Effects of alpha,beta-methylene ATP on resistance and capacitance blood vessels of the cat intestinal circulation; a comparison with other vasoconstrictor agents and sympathetic nerve stimulation.
The autoperfused intestinal circulation of pentobarbitone anaesthetized cats was used to study the effects of alpha,beta-methylene ATP (1-100 micrograms i.a.) on pre-capillary resistance vessels and post-capillary capacitance (venous) blood vessels in comparison with other vasoconstrictor agents (also given i.a.) and the effects of sympathetic nerve stimulation (0.25-16 Hz). All cats were treated with atropine and propranolol. alpha,beta-Methylene ATP, noradrenaline and sympathetic nerve stimulation all caused dose- or frequency-dependent constriction of both resistance and capacitance vessels. alpha,beta-Methylene ATP was particularly active on capacitance vessels causing a greater constriction than either noradrenaline or sympathetic nerve stimulation. In comparison, angiotensin II and vasopressin caused a selective constriction of resistance vessels and prostaglandin F2 alpha a selective constriction of capacitance vessels. The results demonstrate that functional P2x purinoceptors are present on both arterial and venous blood vessels of the cat intestinal circulation.
Taylor
E M
EM
SmithKline Beecham Pharmaceuticals, Welwyn, Hertfordshire, U.K.
Parsons
M E
ME
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002415:Cats; D005260:Female; D007422:Intestines / Q000098:blood supply / Q000187:drug effects*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010477:Perfusion; D013564:Sympathetic Nervous System / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D014662:Vasoconstrictor Agents; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D009638:Norepinephrine