(Hypertension. 1995;26:425-431.)
© 1995 American Heart Association, Inc.
Articles |
Differential Modulation of Baroreceptor Sensitivity by Long-term Antihypertensive Treatment
Presented in part at the 8th International Symposium on SHR and Related Studies, Osaka, Japan, October 18-20, 1994, and published in abstract form (Clin Exp Pharmacol Physiol. 1994[suppl 1]:S30).
From the Department of Internal Medicine, Keio University, School of Medicine, Tokyo, Japan.
Correspondence to Takao Saruta, MD, Department of Internal Medicine, Keio University, School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160, Japan.
Abstract We investigated the effects of long-term oral treatment with four different classes of antihypertensive drugs (a thiazide diuretic [trichlormethiazide, 10 mg/kg per day]; a ß-blocker [atenolol, 90 mg/kg per day]; a calcium channel antagonist [nicardipine, 150 mg/kg per day]; and an angiotensin-converting enzyme inhibitor [enalapril maleate, 10 mg/kg per day]) on aortic baroreceptor activity in spontaneously hypertensive rats with chronic hypertension (36 weeks of age). Treatment with each of the four drugs, given from 10 to 36 weeks of age, similarly decreased arterial pressure (171±2 to 144±1 mm Hg, P<.01) and similarly decreased the threshold pressure for baroreceptors (116±3 to 103±1 mm Hg, P<.05). The four antihypertensive drugs also potentiated the maximal gain of the pressure-activity relation in these rats (untreated, 1.08±0.05% maximum/mm Hg); however, nicardipine and enalapril (1.77±0.04% and 1.70±0.06% maximum/mm Hg, respectively) augmented the maximal gain to a greater extent (P<.05 to .01) than did trichlormethiazide or atenolol (1.49±0.05% and 1.42±0.02% maximum/mm Hg, respectively). When the initiation of treatment was delayed to 28 weeks of age, no differences were found in the effects on either threshold pressure (104±1 mm Hg) or maximal gain (1.36±0.03% maximum/mm Hg) for all four drugs. These findings suggest that in the treatment of chronic hypertension (1) baroreceptor resetting to a lower pressure level is similarly induced with the four drugs, and (2) baroreceptor sensitivity is augmented more by early and long-term treatment with calcium channel antagonists or angiotensin-converting enzyme inhibitors than by diuretics or ß-blockers.
Key Words: pressoreceptors • rats, inbred SHR • angiotensin-converting enzyme inhibitors • calcium channel blockers • diuretics • adrenergic beta antagonists • aorta
This article has been cited by other articles:
 |
|
 |
|
  J. Zicha and J. Kunes Ontogenetic Aspects of Hypertension Development: Analysis in the Rat Physiol Rev, October 1, 1999; 79(4): 1227 - 1282. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Jin, L. Chao, and J. Chao Potassium supplement upregulates the expression of renal kallikrein and bradykinin B2 receptor in SHR Am J Physiol Renal Physiol, March 1, 1999; 276(3): F476 - F484. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Uechi, K. Asai, N. Sato, and S. F. Vatner Voltage-Dependent Calcium Channel Promoter Restores Baroreflex Sensitivity in Conscious Dogs With Heart Failure Circulation, September 29, 1998; 98(13): 1342 - 1347. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Tsuchihashi, S. Kagiyama, Y. Ohya, I. Abe, and M. Fujishima Antihypertensive Treatment and the Responsiveness to Glutamate in Ventrolateral Medulla Hypertension, January 1, 1998; 31(1): 73 - 76. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Nishizawa, H. Kumagai, M. Ichikawa, N. Oshima, H. Suzuki, and T. Saruta Improvement in Baroreflex Function by an Oral Angiotensin Receptor Antagonist in Rats With Myocardial Infarction Hypertension, January 1, 1997; 29(1): 458 - 463. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Kumagai, H. Suzuki, M. Ichikawa, M. Jimbo, M. Nishizawa, M. Ryuzaki, and T. Saruta Comparison of Early and Late Start of Antihypertensive Agents and Baroreceptor Reflexes Hypertension, February 1, 1996; 27(2): 209 - 218. [Abstract] [Full Text]
|
|