THE EFFECTS OF (+/-)-IDAZOXAN AND ITS STEREOISOMERS ON MOUSE VAS-DEFERENS MOTILITY INVITRO - A COMPARISON WITH YOHIMBINE

被引:2
作者
CARRATU, MR
NAVARRA, P
DESERIO, A
SERIO, M
PREZIOSI, P
MITOLOCHIEPPA, D
机构
[1] UNIV CATTOLICA SACRO CUORE, SCH MED, INST PHARMACOL, LARGO F VITO 1, I-00168 ROME, ITALY
[2] UNIV BARI, SCH MED, INST PHARMACOL, I-70124 BARI, ITALY
关键词
IDAZOXAN STEREOISOMER; PARA-AMINOCLONIDINE; YOHIMBINE; NOREPINEPHRINE; VASDEFERENS; IMIDAZOLINE RECEPTOR;
D O I
10.1111/j.1472-8206.1992.tb00124.x
中图分类号
R9 [药学];
学科分类号
1007 ;
摘要
The effects of idazoxan (IDZ) and its stereoisomers were compared to that of a classical alpha2-antagonist, yohimbine (YOH), on para-aminoclonidine (PAC)- and norepinephrine (NE)-mediated inhibition of the twitch response evoked in the mouse vas deferens by low-frequency (0.1 Hz) field stimulation. (+/-)-IDZ and (+)-IDZ antagonized the inhibitory effects of PAC, (+)-IDZ being twice as potent as (+/-)-IDZ; in contrast, antagonism by (-)-IDZ failed to meet Schild criteria for a competitive mechanism. YOH completely reversed the inhibition of twitch response induced by NE, but not that induced by PAC; in the latter case, residual inhibition was almost fully reversed by (+)-IDZ and to a lesser extent by (+/-)-IDZ, while (-)-IDZ proved ineffective. These results provide pharmacological evidence of alpha2-receptor heterogeneity at the vas deferens level. A possible additional mechanism involving imidazoline binding sites is discussed.
引用
收藏
页码:301 / 307
页数:7
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