Evidence for a noradrenergic innervation to alpha 1A-adrenoceptors in rat kidney.
1. Experiments were undertaken to characterize the alpha 1-adrenoceptor subtype mediating vasoconstrictor responses to periarterial noradrenergic nerve stimulation (PNS) in the isolated perfused kidney of the rat. 2. Vasoconstrictor responses to nerve stimulation were inhibited by prazosin (10 nM), 5-methyl-urapidil (30 nM), and nitrendipine (1 microM) but were resistant to inhibition by chloroethylclonidine (100 microM). 3. 5-Methyl-urapidil (30 nM), chloroethylclonidine (100 microM) and nitrendipine (1 microM) did not inhibit the neuronal release of tritium from nerves loaded with [3H]-noradrenaline. 4. The results suggest that renovascular alpha 1A-adrenoceptors receive a noradrenergic innervation and that the innervated receptors are coupled to dihydropyridine-sensitive calcium channels.
Institute of Pharmacology, Syntex Research, Palo Alto, California 94304.
D R
DR
Blue
R L
RL
Vimont
D E
DE
Clarke
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D015220:Calcium Channels / Q000502:physiology; D003000:Clonidine / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D007668:Kidney / Q000098:blood supply / Q000294:innervation*; D008297:Male; D009568:Nitrendipine / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D010879:Piperazines / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D015220:Calcium Channels; D010879:Piperazines; D011942:Receptors, Adrenergic, alpha; C057446:5-methylurapidil; C051731:chlorethylclonidine; D009568:Nitrendipine; D003000:Clonidine; D009638:Norepinephrine; D011224:Prazosin