TY - JOUR
T1 - Indications for P2-purinoceptor subtypes in guinea pig smooth muscle
AU - Wiklund, N. Peter
AU - Gustafsson, Lars E.
PY - 1988/4/13
Y1 - 1988/4/13
N2 - The effects of ADP, ATP, 2-methylthio ATP, α,β-methylene ADP (α,βmeADP) and α,βmeATP on smooth muscle tone and the responses to transmural nerve stimulation were studied in isolated longitudinal ileum muscle, in vas deferens and in taenia coli of the guinea pig. The nucleotides evoked contractile responses in the ileum and vas deferens preparations which were blocked by p-chloromercuribenzene sulfonic acid (PCMBS) and evoked relaxation in the taenia which was not affected by PCMBS. The potency order of the agonists in the ileum (2-methylthio ATP was more potent than ATP which was equipotent with ADP) is consistent with the suggestion that there are P2Y receptors in the taenia. The antagonist pattern, including the inefficacy of reactive blue 2, instead suggests a similarity between the ileum receptors and the P2X receptors in vas deferens. However, α,βmeATP did not antagonize the contractile effect of ATP in the ileum, in contrast to its effect in the vas deferens where α,βmeATP did abolish the contractile effect of ATP. The possibilities for classification of a new receptor/site of purine nucleotide action, P2S, are considered.
AB - The effects of ADP, ATP, 2-methylthio ATP, α,β-methylene ADP (α,βmeADP) and α,βmeATP on smooth muscle tone and the responses to transmural nerve stimulation were studied in isolated longitudinal ileum muscle, in vas deferens and in taenia coli of the guinea pig. The nucleotides evoked contractile responses in the ileum and vas deferens preparations which were blocked by p-chloromercuribenzene sulfonic acid (PCMBS) and evoked relaxation in the taenia which was not affected by PCMBS. The potency order of the agonists in the ileum (2-methylthio ATP was more potent than ATP which was equipotent with ADP) is consistent with the suggestion that there are P2Y receptors in the taenia. The antagonist pattern, including the inefficacy of reactive blue 2, instead suggests a similarity between the ileum receptors and the P2X receptors in vas deferens. However, α,βmeATP did not antagonize the contractile effect of ATP in the ileum, in contrast to its effect in the vas deferens where α,βmeATP did abolish the contractile effect of ATP. The possibilities for classification of a new receptor/site of purine nucleotide action, P2S, are considered.
UR - http://www.scopus.com/inward/record.url?scp=0023821267&partnerID=8YFLogxK
U2 - 10.1016/0014-2999(88)90114-8
DO - 10.1016/0014-2999(88)90114-8
M3 - Article
C2 - 2838305
AN - SCOPUS:0023821267
SN - 0014-2999
VL - 148
SP - 361
EP - 370
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
IS - 3
ER -