Alpha 1D- and alpha 1A-adrenoceptors mediate contraction in rat renal artery.
To investigate the alpha 1-adrenoceptor subtype(s) mediating contraction in rat renal artery, we have compared the effect of the alpha 1-adrenoceptor antagonists, 5-methylurapidil, BMY 7378 (8-(2-(4-(2-methoxyphenyl)-1-piperazinyl) ethyl) 8-azaspiro (4.5) decane-7,9-dione 2HCl) and chloroethylclonidine on functional responses to noradrenaline. A clear blockade by chloroethylclonidine (10(-4) M) of noradrenaline-induced contraction was observed and, along with this effect. pKB values of 9.12 and 8.40 for BMY 7378 and 9.75 and 10.06 for 5-methylurapidil were obtained, indicating that the renal artery expresses the alpha 1D-adrenoceptor subtype as the one involved in contraction and not only the alpha 1A subtype as has been reported.
Villalobos-Molina
R
R
Departamento de Farmacología y Toxicología, CINVESTAV-IPN, México, D.F., Mexico.
López-Guerrero
J J
JJ
Ibarra
M
M
D000818:Animals; D003000:Clonidine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects / Q000502:physiology*; D012077:Renal Artery / Q000187:drug effects / Q000502:physiology*
C547715:Adra1a protein, rat; C547721:Adra1d protein, rat; D010879:Piperazines; D018340:Receptors, Adrenergic, alpha-1; C057446:5-methylurapidil; C051731:chlorethylclonidine; C053428:BMY 7378; D003000:Clonidine; D009638:Norepinephrine