TY - JOUR
T1 - Antagonism of the vasodilator effects of a platelet activating factor precursor in anesthetized spontaneously hypertensive rats
AU - Ma, Yunn Hwa
AU - Dunham, Earl W.
PY - 1988/1/12
Y1 - 1988/1/12
N2 - The hemodynamic effects of platelet activating factor (PAF), PAF antagonist and a precursor of PAF, 1-palmityl-2-acetyl-glycerol (PAG), were examined in pentobarbital-anesthetized spontaneously hypertensive rats to determine whether functionally significant amounts of PAF are produced via the cholinephosphotransferase pathway of PAF synthesis in vivo. Intravenous bolus doses of PAF, PAG and nitroprusside elicited hypotension and active mesenteric vasodilatation. Responses to PAG were slower in onset and longer in duration than those of PAF and nitroprusside. The specific PAF antagonists, CV-3988 and SRI 63-675, attenuated PAG- and PAF-, but not nitroprusside-induced changes in blood pressure and mesenteric flow/resistance. In contrast, captopril, which blocked the effects of angiotensin I, did not influence the hypotension caused by PAG, PAF and nitroprusside. The results suggest that the vasodilator effects of PAG are attributable to PAF produced from this alkylacetylglycerol, and the renin-angiotensin system does not appear to influence the biotransformation of PAG of PAF or the hypotensive action of PAF.
AB - The hemodynamic effects of platelet activating factor (PAF), PAF antagonist and a precursor of PAF, 1-palmityl-2-acetyl-glycerol (PAG), were examined in pentobarbital-anesthetized spontaneously hypertensive rats to determine whether functionally significant amounts of PAF are produced via the cholinephosphotransferase pathway of PAF synthesis in vivo. Intravenous bolus doses of PAF, PAG and nitroprusside elicited hypotension and active mesenteric vasodilatation. Responses to PAG were slower in onset and longer in duration than those of PAF and nitroprusside. The specific PAF antagonists, CV-3988 and SRI 63-675, attenuated PAG- and PAF-, but not nitroprusside-induced changes in blood pressure and mesenteric flow/resistance. In contrast, captopril, which blocked the effects of angiotensin I, did not influence the hypotension caused by PAG, PAF and nitroprusside. The results suggest that the vasodilator effects of PAG are attributable to PAF produced from this alkylacetylglycerol, and the renin-angiotensin system does not appear to influence the biotransformation of PAG of PAF or the hypotensive action of PAF.
KW - Captopril
KW - Cholinephosphotransferase
KW - Hypotension
KW - Palmitylacetylglycerol
KW - Platelet activating factor
KW - Vasodilators
UR - http://www.scopus.com/inward/record.url?scp=0023864289&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023864289&partnerID=8YFLogxK
U2 - 10.1016/0014-2999(88)90226-9
DO - 10.1016/0014-2999(88)90226-9
M3 - Article
C2 - 2832188
AN - SCOPUS:0023864289
SN - 0014-2999
VL - 145
SP - 153
EP - 162
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
IS - 2
ER -