Evidence that ATP does not act as a cotransmitter with noradrenaline in field-stimulated preparations of rat seminal vesicles.
Field stimulation (20 pulses, 60 V, 2 ms, 5-70 Hz) of the nerve terminals within the rat seminal vesicle produced monophasic contractions which were blocked by guanethidine 5 microM and phentolamine 1 microM, and minimal in tissues from rats pretreated with reserpine, but unaffected by repeated application of alpha,beta-methylene ATP. Field stimulation at 40 Hz led to the release of ATP (0.39 +/- 0.12 pmol/mg; n = 10). However neither ATP nor alpha,beta-methylene ATP 10 microM caused contraction of the tissue. We conclude that ATP does not act as a cotransmitter in preparations of rat seminal vesicle because P2-purinoceptors appear to be absent.
Chin
P F
PF
Department of Pharmacology, Monash University, Victoria, Australia.
Pennefather
J N
JN
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology / Q000502:physiology*; D051381:Rats; D011983:Receptors, Purinergic / Q000502:physiology; D012669:Seminal Vesicles / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D009435:Synaptic Transmission
D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D009638:Norepinephrine