Abstract
1. Arterial relaxant responses to beta-adrenoceptor agonists are decreased in spontaneously hypertensive rats (SHR) when compared with normotensive Wistar-Kyoto rats (WKY). To establish which component of the beta-adrenoceptor.adenylate cyclase (AC) system is impaired in the SHR arteries, effects of two activators of AC--cholera toxin (CTX) and forskolin--and of dibutyryl cyclic AMP (db cyclic AMP) were compared between strips of femoral arteries isolated from 13 week-old SHR and age-matched WKY. 2. In the absence of timolol, a beta-adrenoceptor antagonist, contractile responses of the strips to noradrenaline (NA) were significantly greater in the SHR than in the WKY. Timolol augmented the contractile responses to NA to a smaller extent in the SHR than in the WKY. 3. After blockade by timolol of beta-adrenoceptors, contractile responses of the strips to NA through the activation of alpha-adrenoceptors were not significantly different between the two strains. 4. Pre-treatment of the strips with CTX, an activator of the stimulatory GTP-binding protein (Gs), produced a slow-onset and long-lived antagonism of the alpha-adrenoceptor-mediated contractions. The antagonism was much smaller in the SHR than in the WKY. 5. The dose-response curves of the strips from both strains for alpha-adrenoceptor stimulation with NA determined after pretreatment with CTX were comparable to those determined in the absence of timolol. 6. Forskolin, an activator of the catalytic subunit of AC, and DB cyclic AMP also antagonized the alpha-adrenoceptor-mediated contractions. However, these antagonisms were not significantly different between the two strains. 7. Isobutyl methylxanthine (IBMX), an inhibitor of cyclic AMP phosphodiesterase, produced a similar antagonism of the alpha-adrenoceptor-mediated contractions between the two strains. 8. These results suggest that a reduced function of Gs is the main factor responsible for the decreased responsiveness to beta-adrenoceptor stimulation in the SHR femoral artery.
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Selected References
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- Amer M. S. Cyclic adenosine monophosphate and hypertension in rats. Science. 1973 Feb 23;179(4075):807–809. doi: 10.1126/science.179.4075.807. [DOI] [PubMed] [Google Scholar]
- Amer M. S., Gomoll A. W., Perhach J. L., Jr, Ferguson H. C., McKinney G. R. Aberrations of cyclic nucleotide metabolism in the hearts and vessels of hypertensive rats. Proc Natl Acad Sci U S A. 1974 Dec;71(12):4930–4934. doi: 10.1073/pnas.71.12.4930. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Asano M., Aoki K., Matsuda T. Reduced beta adrenoceptor interactions of norepinephrine enhance contraction in the femoral artery from spontaneously hypertensive rats. J Pharmacol Exp Ther. 1982 Oct;223(1):207–214. [PubMed] [Google Scholar]
- Asano M., Hidaka H. Pharmacological properties of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), a calmodulin antagonist in arterial strips from rats and rabbits. J Pharmacol Exp Ther. 1985 Aug;234(2):476–484. [PubMed] [Google Scholar]
- Asano M., Masuzawa K., Matsuda T. Evidence for reduced beta-adrenoceptor coupling to adenylate cyclase in femoral arteries from spontaneously hypertensive rats. Br J Pharmacol. 1988 May;94(1):73–86. doi: 10.1111/j.1476-5381.1988.tb11501.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bender J. L., Wolf L. G., Neer E. J. Interaction of forskolin with resolved adenylate cyclase components. Adv Cyclic Nucleotide Protein Phosphorylation Res. 1984;17:101–109. [PubMed] [Google Scholar]
- Chatelain R. E., Dardik B. N., Robson R. D. Elevated arterial cyclic AMP levels during the development of spontaneous hypertension in rats. Eur J Pharmacol. 1985 Jun 7;112(2):271–275. doi: 10.1016/0014-2999(85)90509-6. [DOI] [PubMed] [Google Scholar]
- Cohen M. L., Berkowitz B. A. Decreased vascular relaxation in hypertension. J Pharmacol Exp Ther. 1976 Feb;196(2):396–406. [PubMed] [Google Scholar]
- Daly J. W. Forskolin, adenylate cyclase, and cell physiology: an overview. Adv Cyclic Nucleotide Protein Phosphorylation Res. 1984;17:81–89. [PubMed] [Google Scholar]
- Donnelly T. E., Jr Lack of altered cyclic nucleotide phosphodiesterase activity in the aorta and heart of the spontaneously hypertensive rat. Biochim Biophys Acta. 1978 Aug 17;542(2):245–252. doi: 10.1016/0304-4165(78)90020-x. [DOI] [PubMed] [Google Scholar]
- Dusseau J. W., Hutchins P. M. Elevated arteriolar adenosine 3',5'-cyclic monophosphate production by SHR. Am J Physiol. 1982 Sep;243(3):H398–H403. doi: 10.1152/ajpheart.1982.243.3.H398. [DOI] [PubMed] [Google Scholar]
- Farfel Z., Brickman A. S., Kaslow H. R., Brothers V. M., Bourne H. R. Defect of receptor-cyclase coupling protein in psudohypoparathyroidism. N Engl J Med. 1980 Jul 31;303(5):237–242. doi: 10.1056/NEJM198007313030501. [DOI] [PubMed] [Google Scholar]
- Furchgott R. F., Zawadzki J. V. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature. 1980 Nov 27;288(5789):373–376. doi: 10.1038/288373a0. [DOI] [PubMed] [Google Scholar]
- Hayashi T., Kunihara M., Tadokoro S. Enhancement of ambulation-increasing effect produced by repeated administration of methamphetamine in rats and neurochemical changes in catecholaminergic neurons. Jpn J Pharmacol. 1987 Mar;43(3):283–290. doi: 10.1254/jjp.43.283. [DOI] [PubMed] [Google Scholar]
- Levine M. A., Downs R. W., Jr, Moses A. M., Breslau N. A., Marx S. J., Lasker R. D., Rizzoli R. E., Aurbach G. D., Spiegel A. M. Resistance to multiple hormones in patients with pseudohypoparathyroidism. Association with deficient activity of guanine nucleotide regulatory protein. Am J Med. 1983 Apr;74(4):545–556. doi: 10.1016/0002-9343(83)91008-2. [DOI] [PubMed] [Google Scholar]
- Levine M. A., Downs R. W., Jr, Singer M., Marx S. J., Aurbach G. D., Spiegel A. M. Deficient activity of guanine nucleotide regulatory protein in erythrocytes from patients with pseudohypoparathyroidism. Biochem Biophys Res Commun. 1980 Jun 30;94(4):1319–1324. doi: 10.1016/0006-291x(80)90563-x. [DOI] [PubMed] [Google Scholar]
- Northup J. K., Sternweis P. C., Smigel M. D., Schleifer L. S., Ross E. M., Gilman A. G. Purification of the regulatory component of adenylate cyclase. Proc Natl Acad Sci U S A. 1980 Nov;77(11):6516–6520. doi: 10.1073/pnas.77.11.6516. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ousterhout J. M., Steinsland O. S. Effects of cholera toxin on vasoconstriction and cyclic AMP content of the isolated rabbit ear artery. Life Sci. 1981 Jun 15;28(24):2687–2695. doi: 10.1016/0024-3205(81)90169-7. [DOI] [PubMed] [Google Scholar]
- Ramanathan S., Shibata S. Cyclic amp blood vessels of spontnaeously hypertensive rat. Blood Vessels. 1974;11(5-6):312–318. doi: 10.1159/000158024. [DOI] [PubMed] [Google Scholar]
- Richards K. L., Douglas S. D. Pathophysiological effects of Vibrio cholerae and enterotoxigenic Escherichia coli and their exotoxins on eucaryotic cells. Microbiol Rev. 1978 Sep;42(3):592–613. doi: 10.1128/mr.42.3.592-613.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sands H., Sinclair D., Mascali J. Cyclic AMP and protein kinase in the spontaneously hypertensive rat aorta and tissue-cultured aortic smooth muscle cells. Blood Vessels. 1976;13(6):361–373. doi: 10.1159/000158106. [DOI] [PubMed] [Google Scholar]
- Seamon K. B., Daly J. W. Forskolin: a unique diterpene activator of cyclic AMP-generating systems. J Cyclic Nucleotide Res. 1981;7(4):201–224. [PubMed] [Google Scholar]
- Silver P. J., Michalak R. J., Kocmund S. M. Role of cyclic AMP protein kinase in decreased arterial cyclic AMP responsiveness in hypertension. J Pharmacol Exp Ther. 1985 Mar;232(3):595–601. [PubMed] [Google Scholar]
- Triner L., Vulliemoz Y., Verosky M., Manger W. M. Cyclic adenosine monophosphate and vascular reactivity in spontaneously hypertensive rats. Biochem Pharmacol. 1975 Mar 15;24(6):743–745. doi: 10.1016/0006-2952(75)90253-1. [DOI] [PubMed] [Google Scholar]
- Tsujimoto G., Lee C. H., Hoffman B. B. Age-related decrease in beta adrenergic receptor-mediated vascular smooth muscle relaxation. J Pharmacol Exp Ther. 1986 Nov;239(2):411–415. [PubMed] [Google Scholar]
- Vegesna R. V., Diamond J. Effects of isoproterenol and forskolin on tension, cyclic AMP levels, and cyclic AMP dependent protein kinase activity in bovine coronary artery. Can J Physiol Pharmacol. 1984 Sep;62(9):1116–1123. doi: 10.1139/y84-187. [DOI] [PubMed] [Google Scholar]
