PHARMACOLOGICAL CHARACTERIZATION OF POSTSYNAPTIC ALPHA-ADRENOCEPTOR SUBTYPES IN 5 DIFFERENT DOG ARTERIES INVITRO

• Type: Another Publication in an International Scientific Journal
• Date: 1985

Authors

POLONIA, JJ (Author) FMUP; PAIVA, MQ (Author) Other; GUIMARAES, S (Author) Other

Journal

Title: Journal of Pharmacy and Pharmacology

Vol. 37

Pages: 205-208

ISSN: 0022-3573

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 24 Citations

Scopus - 13 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-001-WEN

Abstract (EN): The responses of helically cut strips of arteries isolated from five different sites in the body of dogs to relatively selective ¿1- and ¿2-adrenoceptor agonists and the antagonism exerted on these responses by relatively selective ¿1- and ¿2-adrenoceptor blockers have been studied. On all arteries (renal, splenic, cranial mesenteric, jejunal and femoral) phenylephrine was a full agonist whereas UK-13, 304 was a partial agonist causing maximal contractions of 49, 30, 27, 27 and 10% of the maximum, respectively. Phenylephrine was more potent than UK-14,304, being 9 times more potent in the renal artery and up to 42 times more potent in the cranial mesenteric artery. In the dog saphenous vein, where there are both ¿1- and ¿2-adrenoceptors, it has been previously shown that UK-14,304 is 530 times more potent than phenylephrine. Prazosin in low concentrations displaced concentration-response curves for both phenylephrine and UK-14,304 (pA2 values of 8.16-8.43 and 8.13-8.79, respectively) whereas yohimbine was much less potent (pA2 values of 6.53-6.88 and 6.50-7.20, respectively). The results suggest that the ¿-adrenoceptors of all arteries studied are predominantly, if not exclusively, of the ¿1-subtype.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4