Abstract
Arterioles of the guinea pig small intestine constricted in response to norepinephrine, but the constriction was not maintained. The duration of constriction was reduced after pretreatment by theophylline, 3-isobutyl-1-methyl-xanthine, bromo-cAMP, or bromo-cGMP, suggesting that the relaxation was related to an increase in cyclic nucleotide levels in the cell. Forskolin also reduced the duration of constriction, suggesting the involvement of cAMP. The duration of constriction was not affected by propranolol or isoprenaline, indicating no involvement of beta adrenoceptors. A scheme to explain these observations, in which alpha 1-adrenoceptor activation stimulates adenylate cyclase, leading to a rise in cAMP and an increased rate of intracellular calcium sequestration is proposed. The resulting fall in intracellular calcium leads to repolarization and relaxation.
References
May 1, 1977·British Journal of Pharmacology·J C DoxeyJ M Walker
Mar 1, 1975·Metabolism: Clinical and Experimental·G SchultzJ G Hardman
Dec 1, 1977·The Journal of Physiology·G D Hirst
Jan 31, 1979·Naunyn-Schmiedeberg's Archives of Pharmacology·K D SchultzG Schultz
Oct 25, 1979·Nature·E Mueller, C van Breemen
Aug 1, 1987·The Journal of Physiology·N G Byrne, W A Large
Mar 22, 1988·European Journal of Pharmacology·G C GraceG J Dusting
Mar 1, 1986·Journal of Autonomic Pharmacology·J A Leedham, J N Pennefather
May 1, 1987·Circulation Research·T O Neild, N Kotecha
May 1, 1987·The Journal of Physiology·T O Neild
Sep 28, 1971·Biochemistry·C A FreeS M Hess
Nov 1, 1971·The American Journal of Physiology·G Ross
Dec 1, 1971·British Journal of Pharmacology·J W Fara
Jan 1, 1982·Progress in Neurobiology·T O Neild, E Zelcer
May 2, 1980·European Journal of Pharmacology·S YamadaW R Roeske
Dec 1, 1983·Pflügers Archiv : European journal of physiology·K D Meisheri, J C Ruegg
Jul 1, 1983·Microvascular Research·L C MaxwellG L Riedel
Jun 1, 1984·The Journal of Physiology·T B BoltonT Takewaki
May 1, 1982·The Journal of Physiology·C C Aickin, A F Brading
Nov 1, 1982·The Journal of Physiology·J M Marshall
Citations
Mar 17, 1992·European Journal of Pharmacology·E BungardtA Surprenant
Oct 6, 1992·European Journal of Pharmacology·E BungardtE Mutschler
Apr 1, 1990·Journal of the Autonomic Nervous System·T O Neild, N Kotecha
Jan 1, 1990·General Pharmacology·G P Morley, T O Neild
Aug 12, 1998·Journal of the Autonomic Nervous System·N Kotecha
Apr 1, 1996·Clinical and Experimental Pharmacology & Physiology·A M LowE E Daniel
Mar 1, 1997·Clinical and Experimental Pharmacology & Physiology·T Neild, J Xia
Dec 1, 1990·British Journal of Pharmacology·K Z ShenA Surprenant
Nov 1, 1992·British Journal of Pharmacology·J XiaN Kotecha
May 1, 1995·British Journal of Pharmacology·T O Neild, C J Lewis
Oct 1, 1990·Circulation Research·S VannerA Surprenant
Feb 12, 1998·The American Journal of Physiology·J Xia, B R Duling