Selective blockade by nifedipine of 'purinergic' rather than adrenergic nerve-mediated vasopressor responses in the pithed rat.
1. Nifedipine can attenuate pressor responses to sympathetic nerve stimulation both in the presence and in the absence of alpha-adrenoceptor blocking agents. 2. In the presence of alpha,beta-methylene ATP, nifedipine produces only a small attenuation of the vasopressor response. 3. Nifedipine attenuates the vasopressor response produced by intravenous bolus administration of alpha,beta-methylene ATP. 4. The results suggest that the purinergic component of the vasopressor response to stimulation of the sympathetic outflow in the rat is subject to blockade by nifedipine, whereas the alpha-adrenoceptor-mediated response to co-transmitter noradrenaline is relatively resistant.
Bulloch
J M
JM
Institute of Physiology, University of Glasgow.
McGrath
J C
JC
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D003655:Decerebrate State; D005703:Gallamine Triethiodide / Q000494:pharmacology; D006221:Halothane / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology*; D011224:Prazosin / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011983:Receptors, Purinergic / Q000187:drug effects*; D013564:Sympathetic Nervous System / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D015016:Yohimbine / Q000494:pharmacology
D011941:Receptors, Adrenergic; D011983:Receptors, Purinergic; D014662:Vasoconstrictor Agents; D015016:Yohimbine; D000255:Adenosine Triphosphate; D011433:Propranolol; D009543:Nifedipine; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D005703:Gallamine Triethiodide; D006221:Halothane; D011224:Prazosin