(Hypertension. 1997;30:708.)
© 1997 American Heart Association, Inc.
Articles |
Gene Transfer to Carotid Sinus In Vivo
A Novel Approach to Investigation of Baroreceptors
From the Cardiovascular Center and the Departments of Internal Medicine (S.S.M., H.Z.M., M.W.C.) and Pharmacology (D.D.H.), University of Iowa College of Medicine, Iowa City, and the Department of Veterans Affairs Medical Center, Iowa City (M.W.C.), Iowa.
Correspondence to Mark W. Chapleau, PhD, Department of Internal Medicine, E327 General Hospital, University of Iowa, 200 Hawkins Dr, Iowa City, Iowa 52242.
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Abstract |
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Abstract Baroreceptor nerve endings are located in the adventitia of the carotid sinuses and aortic arch. The goal of the present study was to develop a method for gene transfer to the carotid sinus adventitia. Replication-deficient adenovirus containing the gene for Escherichia coli ß-galactosidase (ß-Gal) was applied topically to the carotid sinuses of anesthetized rabbits. Transgene expression was localized by histochemical staining and quantified by chemiluminescence assay (Galacto-Light). Possible effects of adenovirus on baroreceptor sensitivity were investigated by recording baroreceptor activity from the vascularly isolated carotid sinus over a pressure range of 0 to 160 mm Hg. ß-Gal expression in carotid sinus was evident 1 day after virus application, was dose dependent, and was markedly enhanced after 4 days. Expression was restricted to the adventitia of the vessel wall and was not present in vehicle-treated carotid sinuses. Baroreceptor sensitivity measured from carotid sinuses exposed to adenovirus 4 to 5 days beforehand was not altered compared with that measured from control carotid sinuses. In summary, topical application of adenoviral vectors to the carotid sinus provides transgene expression restricted to the region of baroreceptor innervation. The technique provides a novel approach to delineate mechanisms involved in baroreceptor activation and to deliver neuroactive gene products to the baroreceptors.
Key Words: baroreceptors • carotid sinus • gene transfer • adenovirus • blood pressure
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Introduction |
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Baroreceptor sensory nerves terminate in the adventitia of the carotid sinuses and aortic arch and play a major role in the reflex regulation of the circulation.1 2 Baroreceptor activity is influenced by mechanical coupling of the nerve endings to the vascular wall and by the local concentration of chemical factors released from nearby cells or circulating in the blood.2 3 4 5 6 7 8 9 10
Investigation into local mechanisms that modulate baroreceptor activity has relied almost exclusively on short-term experiments. We reasoned that manipulation of gene expression through gene transfer might provide a novel method to investigate both acute and chronic influences on baroreceptor function. Recent advances in gene transfer technology have provided new insights into cellular and molecular mechanisms and have led to novel therapeutic approaches in many areas of biology and medicine.11 12 13 We have recently demonstrated gene transfer into cultured sensory neurons isolated from nodose ganglia (site of aortic baroreceptor cell soma) using adenoviral vectors.14 Several groups including our own have used adenovirus to transfer genes to blood vessels.15 16 17 18 19 20 21 Particularly relevant to the present study is the finding that perivascular administration of adenoviral vectors results in expression of the transgene only in the adventitia and not the media.15 16 Thus, topical application of adenoviral vectors to carotid sinuses may selectively transduce cells in the region of baroreceptor endings in the adventitia without directly influencing vascular function. The method may also transduce the baroreceptor neurons. Previous studies have demonstrated that adenoviral vectors can be taken up by nerve endings and retrogradely transported to the cell somata to alter gene expression.22 23
The major goal of the present study was to develop a method to transfer genes to the carotid sinus adventitia. We used a reporter gene that encodes for the enzyme ß-galactosidase (ß-Gal),13 which is generally not present in mammalian cells, and that can be detected with a histochemical stain and quantified by a chemiluminescence assay.13 15 16 17 18 19 20 21 An additional aim of the study was to determine whether exposure of the carotid sinus to the adenovirus vector adversely influences baroreceptor sensitivity.
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Methods |
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A total of 47 carotid sinuses from 30 New Zealand White rabbits of either sex were studied. The experimental procedures were carried out in accordance with institutional guidelines and the Guiding Principles for the Care and Use of Animals approved by the Council of the American Physiological Society.
Adenovirus Vector
An adenovirus vector containing the gene encoding for
ß-Gal was constructed in the University of Iowa Gene Transfer Vector
Core Laboratory. Construction of the recombinant adenoviral vector has
been described in detail elsewhere.13 In brief, the cDNA
for ß-Gal was cloned into a shuttle vector containing sequences from
serotype 5 human adenovirus, the Rous sarcoma virus (RSV) promoter to
drive transcription, and a simian virus 40 polyadenylation signal. The
resulting plasmid and a plasmid containing the serotype 5 human
adenovirus genome with deletions in the E1A, E1B, and a portion of the
E3 regions were cotransfected into human embryonic kidney (293) cells.
Homologous recombination within the 293 cells produced the
replication-deficient vector (AdRSVß-Gal). We chose to use the RSV
promoter on the basis of our previous study that compared RSV and
cytomegalovirus promoters for gene transfer into cultured nodose
sensory neurons.14 AdRSVß-Gal was subjected to double
cesium gradient purification, suspended in 3% sucrose solution
(1012 particles/mL, or 
1010 plaque forming
units [pfu]/mL), and stored at -70°C.
Application of Adenovirus to Carotid Sinuses
Rabbits were anesthetized with xylazine (20
mg/kg) and ketamine (55 mg/kg) administered
intramuscularly. Under sterile surgical technique, either one or both
carotid sinuses were exposed via a small incision in the cervical
region. The carotid sheath was opened, and either adenovirus suspension
or vehicle solution (3% sucrose) was applied topically to the carotid
sinus region within the sheath by using a pipette. The sheath
restricted the solutions to the region of the carotid bifurcation and
prevented spread of the solutions to adjacent tissues. The dose of
adenovirus administered was either 5x107,
2.5x108, or 5x108 pfu suspended in either 25
or 50 µL of sucrose solution. No attempt was made to remove the small
volume of viral suspension. The incisions were closed and the rabbits
were observed until they regained consciousness. Penicillin (600 000
U) was administered before surgery.
Analysis of ß-Gal Expression
Qualitative analysis and localization of ß-Gal
expression were performed on 19 carotid sinuses from 12 rabbits by
using a histochemical procedure.13 15 16 17 Twelve carotid
sinuses exposed to AdRSVß-Gal and 7 control sinuses (5 exposed to
sucrose vehicle and 2 from intact rabbits) were analyzed. In
brief, the carotid sinus region was removed, rinsed with PBS, and fixed
in 0.5% glutaraldehyde for 30 minutes at room
temperature. The blood vessel segments were then washed with PBS
containing MgCl2 (1 mmol/L) and exposed to
K3Fe(CN)6 (4.9 mmol/L),
K4Fe(CN)6 (4.7 mmol/L), and
5-bromo-4-chloro-3-indolyl-ß-D-galactopyranoside (X-Gal,
2.4 mmol/L) in PBS containing MgCl2 for 1 hour
at 37°C. X-Gal is hydrolyzed by ß-Gal to produce an indolyl that is
oxidized to an indigo blue derivative.13 The X-Gal
solution was then replaced with PBS, and the blood vessels were stored
at 4°C. Photographs were taken of the carotid sinus region and cross
sections of 20-µm thickness.
In separate experiments (20 carotid sinuses from 10 rabbits), ß-Gal activity in the carotid sinus region was measured quantitatively by chemiluminescence (Galacto-Light Plus, Tropix). Sixteen sinuses exposed to AdRSVß-Gal and 4 sinuses exposed to sucrose vehicle were analyzed. Each carotid sinus region was minced and placed in lysis buffer (0.2% Triton X-100 and 100 mmol/L potassium phosphate in 175 µL, pH 7.8) for 20 minutes. The samples were centrifuged at 12 000 rpm for 10 minutes and the supernatant removed. Supernatants were analyzed for ß-Gal activity with 3-(4-methoxyspirol-[1,2-dioxetane-3,21-tricyclo-[3.3.1.13,7]decan]-4-yl)-phenyl-ß-D-galactopyranoside. The reaction produces light that can be detected by a Monolight 2010 luminometer (Analytical Luminescence Laboratory Inc). Standards of purified Escherichia coli ß-Gal (Boehringer Mannheim) were used to generate a standard curve. ß-Gal activity was expressed in milliunits per milligram protein (Bio-Rad DC protein assay).
Analysis of Baroreceptor Sensitivity
Baroreceptor sensitivity was evaluated in 3 rabbits 4 to 5 days
after topical application of AdRSVß-Gal (5x108 pfu) to
the carotid sinus and in 8 control rabbits. The 3 carotid sinuses
exposed to adenovirus were stained with X-Gal after each experiment to
confirm gene transfer. Rabbits were anesthetized with sodium
pentobarbital (30 to 35 mg/kg IV) and ventilated through a
tracheotomy with room air supplemented with O2.
Arterial blood gases and pH were kept within normal ranges
by adjusting the ventilation. Catheters were introduced into the
femoral artery for measurement of arterial pressure and in
the femoral vein for administration of supplemental anesthetic when
needed.
In each rabbit, one carotid sinus was vascularly isolated as described previously.5 6 8 9 10 Catheters were placed in the common carotid and lingual arteries, and the carotid sinus was filled with oxygenated Krebs-Henseleit buffer. Carotid sinus pressure was controlled by varying the inflow of air into a pressure bottle attached to the common carotid artery catheter and was measured with a transducer (model P23ID, Statham) connected to the lingual artery catheter.5 6 8 9 10 The cervical sympathetic, aortic depressor, and vagus nerves were sectioned. Decamethonium bromide (0.3 mg/kg IV) was administered to eliminate skeletal muscle contractions before recording nerve activity.
The carotid sinus nerve was isolated, sectioned, and placed on a unipolar electrode. The electrode and nerve were insulated either by covering the area with warm paraffin oil (37°C) and/or by encasing them in Wackers silicone gel.8 9 10 Nerve activity was recorded using a high-impedance probe (model HIP511J, Grass Instrument Co) and a Grass band-pass amplifier (model P511J, 100 to 300 Hz to 3 kHz bandwidth). The neurogram was displayed on a dual-beam storage oscilloscope (model 5113, Tektronix). The frequency of action potentials exceeding a selected voltage level just above the electrical noise was counted with a nerve traffic analyzer (model 706C, Department of Bioengineering, University of Iowa, Iowa City).5 6 8 9 10 Systemic arterial pressure, carotid sinus pressure, and the output of the nerve traffic analyzer were continuously recorded on a chart recorder (model 11-1202-25, Gould Inc).
Baroreceptor activity was recorded during slow ramp increases in nonpulsatile carotid sinus pressure from 0 to 160 mm Hg. Pressure ramps were repeated once approximately every 5 minutes until baroreceptor responses were consistent and reproducible. Carotid sinus pressure was held at 60 mm Hg in between pressure ramps in all experiments. The rate of pressure rise (dP/dt) was equivalent during all pressure ramps within each experiment and was similar in virus-treated (2.9±0.3 mm Hg/s) and control (2.7±0.2 mm Hg/s) carotid sinuses.
Baroreceptor activity was measured at 20–mm Hg increments in pressure over a range of 20 to 160 mm Hg. The data from three or four pressure ramps with consistent baroreceptor responses were analyzed and the average responses calculated for each experiment. Because the absolute level of multifiber baroreceptor activity (in spikes per second) varies from preparation to preparation, baroreceptor activity was expressed as a percentage of the maximum activity recorded at high carotid sinus pressure for analysis of differences between virus-treated and control carotid sinuses. The slope of the linear region of the baroreceptor pressure-activity (%) curve was calculated using linear regression analysis and served as a measure of baroreceptor sensitivity.8 9 The linear region of the curve occurred between 40 and 100 mm Hg (r=.989±.004). The position of the curve along the pressure axis was also determined directly from the experimental traces by measuring the carotid sinus pressure corresponding to 50% of the maximum baroreceptor activity (EP50).
Statistical Analysis of Data
All data are expressed as mean±SEM. The levels of ß-Gal
activity in carotid sinuses from the various experimental groups were
analyzed by one-factor ANOVA and the Tukey-Kramer post hoc test
(GB-Stat 6.0 software). The effects of changes in carotid sinus
pressure and treatment group (virus-treated versus control carotid
sinuses) on normalized baroreceptor activity were analyzed by
two-factor ANOVA and the Tukey-Kramer post hoc test (GB-Stat 6.0
software). Differences in baroreceptor slope and EP50
between the groups were determined by unpaired t test.
Statistical significance of differences was determined at
P<.05.
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Results |
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Gene Transfer to the Carotid Sinus
ß-Gal expression, as indicated by positive X-Gal staining, was observed in each carotid sinus exposed to AdRSVß-Gal (12 of 12 carotid sinuses; Fig 1). Expression of ß-Gal was not observed in carotid sinuses exposed to sucrose vehicle (n=5) or in untreated carotid sinuses (n=2; Fig 1). Expression was observed both 1 (n=6) and 4 (n=6) days after virus application, and the intensity of staining appeared greater after 4 days than after 1 day.
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Cross sections of the carotid sinus region exposed to the adenovirus vector indicated that ß-Gal expression was restricted to the adventitia of the blood vessel wall (n=3, Fig 2). Staining for ß-Gal was never observed in the media or intima.
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ß-Gal activity was measured by chemiluminescence assay. AdRSVß-Gal applied topically to carotid sinuses produced dose-dependent increases in ß-Gal activity 1 day after application of the virus (n=12, Fig 3). Four days after virus application, ß-Gal activity was more than 25-fold greater than that measured 1 day after the same dose of virus was applied (n=4, Fig 3). ß-Gal activity was absent in carotid sinuses exposed to sucrose vehicle (n=4, Fig 3).
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P<.05, 4 days vs 1 day
at the same dose of virus.
Baroreceptor Sensitivity
Baroreceptor activity was recorded from the vascularly
isolated carotid sinus to evaluate the effects of exposure to the
adenovirus. The experiments were conducted 4 to 5 days after
application of the virus (5x108 pfu AdRSVß-Gal) to the
carotid sinus at a time when ß-Gal expression was pronounced (Fig 3).
There were no significant differences in the levels of normalized
baroreceptor activity at equivalent pressures measured from
virus-treated and control carotid sinuses (Fig 4). In addition, neither the slope of the
pressure-activity curve nor the EP50 values were
significantly different between the groups. The slope averaged
1.24±0.09 and 1.21±0.25%/mm Hg for control and virus-treated
sinuses, respectively. There was a tendency for the virus-treated
carotid sinuses to exhibit a leftward shift in the pressure-activity
curve; EP50 values averaged 77±5 and 62±7 mm Hg for
control and virus-treated carotid sinuses, respectively.
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Discussion |
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The major findings of the present study are that (1) gene transfer to the carotid sinus of intact rabbits can be accomplished by using an adenovirus vector; (2) after perivascular application of adenovirus, expression of the transgene is restricted to the region of baroreceptor innervation in the adventitia; (3) transgene expression driven by the RSV promoter occurs within 1 day of virus application and is markedly enhanced after 4 days; and (4) exposure of the carotid sinus to the adenovirus vector does not appear to adversely influence baroreceptor sensitivity.
Applications of Gene Transfer to the Carotid Sinus
Gene transfer has been used to gain insight into fundamental
biological mechanisms and to provide novel therapies for
disease.11 12 An advantage of gene transfer over a
pharmacological approach is the potential for longer-term manipulation
of physiological systems. Gene transfer to the
carotid sinus may enable sustained delivery of neuroactive substances
such as neurotrophic factors and prostanoids to the baroreceptors.
Baroreceptor responses to short-term administration of paracrine and
vasoactive factors have been investigated,3 4 5 6 7 8 9 10 whereas
little is known concerning longer-term responses and potential trophic
effects on baroreceptor structure and function.
We demonstrated in the present study that ß-Gal expression was not only maintained but also markedly enhanced between 1 and 4 days after applying adenovirus to the carotid sinus. Although additional studies are needed to determine the maximum duration of altered gene expression in the carotid sinus, our results both in vivo and in isolated sensory neurons14 suggest that transgene expression can be sustained for at least several days. The time course and duration of expression depends in part on the promoter used to drive gene expression.11 12 13 14 15 16 Therefore, the time course of transgene expression can be modified to some extent to meet the needs of a particular experiment by using different promoters.
The importance of baroreceptors in chronic pathologic states such as hypertension and atherosclerosis remains controversial. Decreased baroreflex sensitivity predicts the occurrence of sudden cardiac death in patients with coronary artery disease and myocardial infarction and in animal models.24 25 Baroreflex impairment may be caused by decreased baroreceptor sensitivity or altered central mediation of the reflex. The impact of provoking chronic changes in baroreceptor sensitivity by using gene transfer on the development of hypertension and occurrence of sudden cardiac death would provide new insights into the importance of baroreceptors in those states. Furthermore, restoration of baroreceptor sensitivity by gene transfer would suggest a possible new therapeutic approach.
A second advantage of gene transfer is the ability to specifically alter expression of individual molecules in a regionally selective manner. This is not easily accomplished with a pharmacological approach, particularly during systemic administration of drugs. We found that ß-Gal expression was confined to the adventitia of the carotid sinus after topical application of AdRSVß-Gal. The lack of expression in the media likely reflects a diffusion barrier that prevents the adenovirus vector from crossing the external elastic lamina.18 Rios et al16 have also observed that trans-gene expression following topical application of adenovirus vector to carotid arteries is restricted to the adventitia. We did not investigate whether the adenovirus vector may have reached the systemic circulation by way of absorption into the vasa vasorum in carotid sinus adventitia but believe it is very unlikely. Adenovirus does not easily cross the endothelium,18 20 and intraluminal administration of virus to isolated vessel segments does not generally lead to reporter gene expression at distant sites despite significant expression in the vasa.26 27
Baroreceptor nerve endings are present in the adventitia of carotid sinuses.1 2 Selective targeting of gene transfer to the adventitia may enable modulation of baroreceptor sensitivity by neuroactive factors without interfering with normal gene expression in vascular muscle in the media. In addition, baroreceptor activity may be modulated indirectly by changes in vascular distensibility elicited by delivery of vasoactive substances.2
A third advantage of the gene transfer approach is that the transferred molecule (eg, an enzyme or ion channel) may remain under physiological regulation and therefore may vary its activity in response to appropriate stimuli. For example, paracrine factors such as prostacyclin and nitric oxide are produced intermittently in response to elevations in cytosolic Ca2+ concentration. Mechanical deformation of various types of cells, including baroreceptor neurons, increase cytosolic Ca2+.28 29 30 31 Therefore, gene transfer of prostaglandin H synthase or nitric oxide synthase (NOS) may enable regulated production of prostacyclin and nitric oxide, which may be more physiologically relevant than continuous exposure to exogenously administered factors.
Adenoviral vectors can enter sensory nerve endings and be transported retrogradely to the neuronal soma to alter gene expression.22 23 Therefore, gene transfer to the carotid sinus may enable alteration of gene expression in the baroreceptors themselves and provide a method to modulate electrophysiological properties of nerve endings. Adenovirus-mediated gene transfer of a K+ channel has been used to modify membrane excitability in cardiac myocytes.32 In addition, gene transfer of the endothelial isoform of NOS into hippocampal neurons modifies synaptic transmission.33 Transfer of truncated eNOS, a putative dominant negative inhibitor of endogenous eNOS, prevented long-term potentiation in a subpopulation of hippocampal neurons.33 These studies illustrate that gene transfer may be used to overexpress a functional gene to alter neural function or to block endogenous gene expression.
Limitations of the Study
Several questions remain to be answered before the full potential
of gene transfer can be realized. A major concern with the use of
adenoviral vectors is the potential for the vector itself to cause
biological responses not related to the function of the transferred
gene. Adenovirus triggers immune and inflammatory responses that can
contribute to loss of expression of the transgene.20 21 In
previous studies, the extent of inflammation and the duration of gene
expression have been variable, depending on the type of vector, the
viral titer, the site of virus application, and the species of animal
studied.13 15 16 17 18 19 20 21 The inflammatory response after gene
transfer was not evaluated in the present study but was
investigated by us in a recent study using similar
techniques.16 In that study, no infiltration of
inflammatory cells was observed 1 day after adenovirus vector
containing the ß-Gal gene (0.3 to 1.5x1010 pfu) was
applied topically to carotid and femoral arteries.16 We
used a lower dose of virus (5x107 to 5x108
pfu) in the present study, which may have further limited the
inflammation. It is possible that the inflammatory response to
adenovirus is less severe when it is applied to the adventitia instead
of intravascularly. Our finding that baroreceptor sensitivity was not
significantly altered 4 to 5 days after virus application suggests that
inflammation, if it did occur, did not markedly influence function. The
results also suggest that adenovirus itself does not adversely
influence baroreceptor sensitivity, which will be important when
investigating responses in carotid sinuses transduced with functional
genes. Nevertheless, further studies are needed to characterize the
duration of gene expression and the impact of immune and inflammatory
responses in adenovirus-treated carotid sinuses.
The absolute amount of activity recorded from multiple baroreceptor fibers cannot be easily compared among separate groups of animals because the measured activity varies depending on the contact between the electrode and carotid sinus nerve. Therefore, we expressed activity as a percentage of the maximum activity in each experiment. The analysis allows the sensitivity to changes in pressure and possible shifts in the pressure-activity curve along the pressure axis to be evaluated but does not enable a comparison of maximum baroreceptor activity. One way we plan to overcome this limitation in future experiments is to investigate effects of carotid sinus gene transfer on baroreflex control of systemic arterial pressure and heart rate, the measurements of which are not dependent on the recording conditions and exhibit much less interanimal variability.
The results of the present study do not define which types of cell in the carotid sinus adventitia expressed ß-Gal after gene transfer. The type of cell transduced may not be critically important in studies attempting to deliver paracrine factors to the region of baroreceptor innervation. In contrast, it will be essential to transduce the baroreceptor neurons in studies investigating the neural mechanisms of mechanoelectrical transduction and determinants of membrane excitability.
Summary
The results of the present study demonstrate that gene
transfer to the site of baroreceptor innervation in the carotid sinus
can be accomplished by using an adenovirus vector. Exposure of the
carotid sinus to the vector containing the reporter gene ß-Gal does
not appear to adversely influence baroreceptor sensitivity. The
technique provides a novel approach for future studies of baroreceptor
mechanisms.
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Acknowledgments |
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The work was supported by a grant from the Iowa Affiliate of the American Heart Association and research funds from the Department of Veterans Affairs awarded to M.W. Chapleau and funds available to M.W. Chapleau through a program project grant (PO1-HL-14388) from the National Institutes of Health. Silvana S. Meyrelles was a graduate student enrolled in the Department of Physiological Sciences, Federal University of Espirito Santo Biomedical Center, Vitoria, ES, Brazil, and was supported by funds from CNPq, Brazil during the time that the work was being carried out. The authors thank Drs Beverly L. Davidson and Richard D. Anderson and the Gene Transfer Vector Core at the University of Iowa for providing the adenovirus vector. The Vector Core is supported in part by funds from the University of Iowa Carver Trust. The authors also thank Dr Donald Lund for assistance with the ß-galactosidase chemiluminescence assay, Aaron T. Holley and Melissa Mora for technical assistance, and Jackie Schneider for typing the manuscript.
Received March 18, 1997; first decision April 17, 1997; accepted May 7, 1997.
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References |
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TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
1. Rees PM. Observations on the fine structure and distribution of presumptive baroreceptor nerves at the carotid sinus. J Comp Neurol. 1967;131:517-548.[Medline] [Order article via Infotrieve]
2. Kirchheim HR. Systemic arterial
baroreceptor reflex. Physiol Rev. 1976;56:100-176.
3. Kunze DL, Krauhs JM, Orlea CJ. Direct action of norepinephrine on aortic baroreceptors of rat adventitia. Am J Physiol. 1984;247(Heart Circ Physiol. 16):H811-H816.
4. Goldman WF, Saum WR. A direct excitatory action
of catecholamines on rat aortic baroreceptors in
vitro. Circ Res. 1984;55:18-30.
5. Chen HI, Chapleau MW, McDowell TS, Abboud FM.
Prostaglandins contribute to activation of baroreceptors in
rabbits: possible paracrine influence of
endothelium. Circ Res. 1990;67:1394-1404.
6. Xie P, Chapleau MW, McDowell TS, Hajduczok G, Abboud FM. Mechanism of decreased baroreceptor activity in chronic hypertensive rabbits: role of endogenous prostanoids. J Clin Invest. 1990;86:625-630.[Medline] [Order article via Infotrieve]
7. Chapleau MW, Hajduczok G, Abboud FM. Paracrine
modulation of baroreceptor activity by vascular
endothelium. News Physiol Sci. 1991;6:210-214.
8. Li Z, Abboud FM, Chapleau MW. Aggregating human
platelets in carotid sinus of rabbits decrease sensitivity of
baroreceptors. Circ Res. 1992;70:644-650.
9. Li Z, Su X, Chapleau MW. Role of cyclooxygenase metabolites in mediating platelet-induced baroreceptor dysfunction. Am J Physiol. 1995;269(Heart Circ Physiol. 38):H599-H608.
10. Li Z, Mao HZ, Abboud FM, Chapleau MW.
Oxygen-derived free radicals contribute to baroreceptor dysfunction in
atherosclerotic rabbits. Circ Res. 1996;79:802-811.
11. Schneider MD, French BA. The advent of
adenovirus: gene therapy for cardiovascular
disease. Circulation. 1993;88:1937-1942.
12. Neve RL. Adenovirus vectors enter the brain. Trends Neurosci. 1993;16:251-253.[Medline] [Order article via Infotrieve]
13. Davidson BL, Doran SE, Shewach DS, Latta JM, Hartman JW, Roessler BJ. Expression of Escherichia coli ß-galactosidase and rat HPRT in the CNS of Macaca mulatta following adenoviral mediated gene transfer. Exp Neurol. 1994;125:258-267.[Medline] [Order article via Infotrieve]
14. Meyrelles SS, Sharma RV, Whiteis CA, Davidson BL, Chapleau MW. Adenovirus-mediated gene transfer to cultured nodose sensory neurons. Mol Brain Res. 1997. In press.
15. Ooboshi H, Welsh MJ, Rios CD, Davidson BL, Heistad
DD. Adenovirus-mediated gene transfer in vivo to cerebral blood
vessels and perivascular tissue. Circ Res. 1995;77:7-13.
16. Rios CD, Ooboshi H, Piegors D, Davidson BL, Heistad
DD. Adenovirus-mediated gene transfer to normal and
atherosclerotic arteries: a novel approach. Arterioscler
Thromb Vasc Biol. 1995;15:2241-2245.
17. Lamping KG, Rios CD, Chun JA, Ooboshi H, Davidson BL, Heistad DD. Intrapericardial administration of adenovirus for gene transfer. Am J Physiol. 1997;272(Heart Circ Physiol. 41):H310-H317.
18. Rome JJ, Shayani V, Flugelman MY, Newman KD, Farb A,
Virmani R, Dichek DA. Anatomic barriers influence the
distribution of in vivo gene transfer into the arterial
wall. Arterioscler Thromb. 1994;14:148-161.
19. Barr E, Carroll J, Kalynych AM, Tripathy SK, Kozarsky K, Wilson JM, Leiden JM. Efficient catheter-mediated gene transfer into the heart using replication-defective adenovirus. Gene Ther. 1994;1:51-58.[Medline] [Order article via Infotrieve]
20. Newman KD, Dunn PF, Owens JW, Schulick AH, Virmani R, Sukhova G, Libby P, Dichek DA. Adenovirus-mediated gene transfer into normal rabbit arteries results in prolonged vascular cell activation, inflammation, and neointimal hyperplasia. J Clin Invest. 1995;96:2955-2965.[Medline] [Order article via Infotrieve]
21. Schulick AH, Newman KD, Virmani R, Dichek DA. In
vivo gene transfer into injured carotid arteries: optimization and
evaluation of acute toxicity. Circulation. 1995;91:2407-2414.
22. Ridoux V, Robert JJ, Zhang X, Perricaudet M, Mallet J, Le Gal La Salle G. Adenoviral vectors as functional retrograde neuronal tracers. Brain Res. 1994;648:171-175.[Medline] [Order article via Infotrieve]
23. Ghadge GD, Roos RP, Kang UJ, Wollmann R, Fishman PS, Kalynych AM, Barr E, Leiden JM. CNS gene delivery by retrograde transport of recombinant replication-defective adenoviruses. Gene Ther. 1995;2:132-137.[Medline] [Order article via Infotrieve]
24. La Rovere MT, Speccia G, Mortara A, Schwartz PJ.
Baroreflex sensitivity, clinical correlates, and
cardiovascular mortality among patients with a first
myocardial infarction: a prospective study.
Circulation. 1988;78:816-824.
25. Schwartz PJ, Vanoli E, Stramba-Badiale M, DeFerrari GM,
Billman GE, Foreman RD. Autonomic mechanisms and sudden death:
new insights from analysis of baroreceptor reflexes in
conscious dogs with and without a myocardial infarction.
Circulation. 1988;78:969-979.
26. Guzman RJ, Lemarchand P, Crystal RG, Epstein SE, Finkel
T. Efficient and selective adenovirus-mediated gene transfer
into vascular neointima. Circulation. 1993;88:2838-2848.
27. Feldman LJ, Steg PG, Zheng LP, Chen D, Kearney M, McGarr SE, Barry JJ, Dedieu J-F, Perricaudet M, Isner JM. Low efficiency of percutaneous adenovirus-mediated arterial gene transfer in the atherosclerotic rabbit. J Clin Invest. 1995;95:2662-2671.[Medline] [Order article via Infotrieve]
28. Naruse K, Sokabe M. Involvement of stretch-activated ion channels in Ca2+ mobilization to mechanical stretch in endothelial cells. Am J Physiol. 1993;264(Cell Physiol. 33):C1037-C1044.
29. Glogauer M, Ferrier J, McCulloch CAG. Magnetic fields applied to collagen-coated ferric oxide beads induce stretch-activated Ca2+ flux in fibroblasts. Am J Physiol. 1995;269(Cell Physiol. 38):C1093-C1104.
30. Sharma RV, Chapleau MW, Hajduczok G, Wachtel RE, Waite LJ, Bhalla RC, Abboud FM. Mechanical stimulation increases intracellular calcium concentration in nodose sensory neurons. Neuroscience. 1995;66:433-441.[Medline] [Order article via Infotrieve]
31. Sullivan MJ, Sharma RV, Wachtel RE, Chapleau
MW, Waite LJ, Bhalla RC, Abboud FM. Non–voltage-gated calcium
influx through mechanosensitive ion channels in aortic baroreceptor
neurons. Circ Res. 1997;80:861-867.
32. Johns DC, Nuss HB, Chiamvimonvat N, Ramza BM, Marban E, Lawrence JH. Adenovirus-mediated expression of a voltage-gated potassium channel in vitro (rat cardiac myocytes) and in vivo (rat liver): a novel strategy for modifying excitability. J Clin Invest. 1995;95:1152-1158.
33. Kantor DB, Lanzrein M, Stary SJ, Sandoval GM,
Smith WB, Sullivan BM, Davidson N, Schuman EM. A role for
endothelial NO synthase in LTP revealed by
adenovirus-mediated inhibition and rescue. Science. 1996;274:1744-1748.
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  S. S. Meyrelles, R. V. Sharma, H. Z. Mao, F. M. Abboud, and M. W. Chapleau Modulation of baroreceptor activity by gene transfer of nitric oxide synthase to carotid sinus adventitia Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2003; 284(5): R1190 - R1198. [Abstract] [Full Text] [PDF]
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