This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hayashi, K. Articles by Loutzenhiser, R. Search for Related Content PubMed PubMed Citation Articles by Hayashi, K. Articles by Loutzenhiser, R.

Hypertension, Vol 19, 153-160, Copyright © 1992 by American Heart Association

ARTICLES

Enhanced myogenic responsiveness of renal interlobular arteries in spontaneously hypertensive rats

K Hayashi, M Epstein and R Loutzenhiser
Nephrology Section, Veterans Administration Medical Center, Miami, Fla 33125.

We recently demonstrated that the interlobular artery (ILA) constricts in response to elevating renal arterial pressure (RAP), suggesting that the ILA contributes to renal autoregulation. In the present study, we examined the segmental myogenic responsiveness of the ILA in kidneys from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). The tapered nature of the ILA allowed us to characterize the regional responsiveness, using the basal diameter to define segments as either proximal (greater than 60 microns), intermediate (40-60 microns), or distal (less than 40 microns). At 80 mm Hg, segmental diameters were similar in WKY and SHR arteries (proximal, 76.0 +/- 3.1 versus 71.6 +/- 3.5 microns; intermediate, 48.2 +/- 1.4 versus 48.1 +/- 1.7 microns; distal, 30.7 +/- 0.9 versus 27.9 +/- 1.3 microns for WKY and SHR, respectively). In both strains, intermediate and distal segments exhibited graded reductions in diameter as RAP was elevated, whereas proximal segments did not. Pressure-induced decrements in the diameters of distal ILA segments were similar in WKY (-24 +/- 2%) and SHR (-20 +/- 2%; p greater than 0.1). The intermediate ILA of SHR exhibited an augmented myogenic responsiveness, constricting at lower RAP levels and exhibiting greater maximal decrements in diameter at 180 mm Hg (i.e., - 19 +/- 2% and -12 +/- 2% for SHR and WKY, respectively; p less than 0.05). Nifedipine (1.0 microM) reduced pressure-induced vasoconstriction of intermediate and distal ILA segments by 56 +/- 11% and 79 +/- 7%, respectively, in WKY.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				C. Lau, I. Sudbury, M. Thomson, P. L. Howard, A. B. Magil, and W. A. Cupples Salt-resistant blood pressure and salt-sensitive renal autoregulation in chronic streptozotocin diabetes Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2009; 296(6): R1761 - R1770. [Abstract] [Full Text] [PDF]

				H. A. Drummond, S. C. Grifoni, and N. L. Jernigan A New Trick for an Old Dogma: ENaC Proteins as Mechanotransducers in Vascular Smooth Muscle Physiology, February 1, 2008; 23(1): 23 - 31. [Abstract] [Full Text] [PDF]

				R. Loutzenhiser, K. Griffin, G. Williamson, and A. Bidani Renal autoregulation: new perspectives regarding the protective and regulatory roles of the underlying mechanisms Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2006; 290(5): R1153 - R1167. [Abstract] [Full Text] [PDF]

				Z. Ungvari and A. Koller Endothelin and Prostaglandin H2/Thromboxane A2 Enhance Myogenic Constriction in Hypertension by Increasing Ca2+ Sensitivity of Arteriolar Smooth Muscle Hypertension, November 1, 2000; 36(5): 856 - 861. [Abstract] [Full Text] [PDF]

				T. R. Nurkiewicz and M. A. Boegehold Limitation of arteriolar myogenic activity by local nitric oxide: segment-specific effect of dietary salt Am J Physiol Heart Circ Physiol, November 1, 1999; 277(5): H1946 - H1955. [Abstract] [Full Text] [PDF]

				J. C. McGiff and J. Quilley 20-HETE and the kidney: resolution of old problems and new beginnings Am J Physiol Regulatory Integrative Comp Physiol, September 1, 1999; 277(3): R607 - R623. [Abstract] [Full Text] [PDF]

				T. R. Nurkiewicz and M. A. Boegehold High dietary salt alters arteriolar myogenic responsiveness in normotensive and hypertensive rats Am J Physiol Heart Circ Physiol, December 1, 1998; 275(6): H2095 - H2104. [Abstract] [Full Text] [PDF]

				T. Takenaka, H. Suzuki, H. Okada, K. Hayashi, Y. Ozawa, and T. Saruta Biophysical Signals Underlying Myogenic Responses in Rat Interlobular Artery Hypertension, December 1, 1998; 32(6): 1060 - 1065. [Abstract] [Full Text] [PDF]

				A. Huang and A. Koller Endothelin and Prostaglandin H2 Enhance Arteriolar Myogenic Tone in Hypertension Hypertension, November 1, 1997; 30(5): 1210 - 1215. [Abstract] [Full Text]

				K. Hayashi, H. Suzuki, and T. Saruta Nitric Oxide Modulates but Does Not Impair Myogenic Vasoconstriction of the Afferent Arteriole in Spontaneously Hypertensive Rats : Studies in the Isolated Perfused Hydronephrotic Kidney Hypertension, June 1, 1995; 25(6): 1212 - 1219. [Abstract] [Full Text]