RT Journal Article
SR Electronic
T1 Postjunctional alpha-1 and alpha-2 adrenoceptors in the coronaries of the perfused guinea-pig heart.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 251
OP 257
VO 232
IS 1
A1 N Decker
A1 J Schwartz
YR 1985
UL http://jpet.aspetjournals.org/content/232/1/251.abstract
AB Prazosin and yohimbine were used to differentiate postjunctional alpha adrenoceptors in the coronaries of the perfused guinea-pig heart. Two postjunctional alpha adrenoceptor subtypes were distinguished by the affinities of the receptor for yohimbine and prazosin. The pA2 for yohimbine were 8.74 against alpha-methylnorepinephrine and 8.98 against BHT-920, and the pA2 for prazosin was 9.84 against phenylephrine. Yohimbine was not very active against the alpha-1 selective agonist as was prazosin against the alpha-2 selective agonists. Alpha-1 and alpha-2 postjunctional adrenoceptors mediate vasoconstriction in the whole coronary bed of the perfused guinea-pig heart.