Possible subtypes of ATP receptor producing contraction of rat vas deferens, revealed by cross-desensitisation.
1. Adenosine triphosphate (ATP), alpha beta-methylene ATP and the dinucleotides P1P4diadenosine tetraphosphate (AP4A) and P1P5-diadenosine pentaphosphate (AP5A) have been applied to preparations of the rat vas deferens in vitro in preliminary experiments designed to assess the feasibility of using such nucleotides to detect subtypes of the ATP receptor causing smooth muscle contractions. 2. Desensitisation to the dinucleotides induced a change in the profile of the response to ATP with the preferential loss of an early transient component. 3. Desensitisation to low concentrations of alpha beta-methylene ATP produced a greater loss of the later, slower component of contraction to ATP. 4. It is suggested that these components may therefore involve pharmacologically distinguishable nucleotide receptors.
Stone
T W
TW
Department of Pharmacology and Clinical Pharmacology, School of Medicine, University of Auckland, New Zealand.
Paton
D M
DM
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D015226:Dinucleoside Phosphates / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011983:Receptors, Purinergic / Q000378:metabolism*; D014649:Vas Deferens / Q000187:drug effects
D015226:Dinucleoside Phosphates; D011983:Receptors, Purinergic; C012275:P(1),P(5)-di(adenosine-5'-)pentaphosphate; C020733:diadenosine tetraphosphate; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate