モルモット輸精管におけるGuanethidineの交感神経遮断作用に対するPhenoxybenzamineの影響
1980 年 100 巻 12 号 p. 1247-1251
詳細
1980 年 100 巻 12 号 p. 1247-1251
The interaction of guanethidine (Guan) and phenoxybenzamine (PBA) has been studied for the responses to hypogastric nerve stimulation (HS) and transmural stimulation (TS) of guinea pig vas deferens. Response to TS (40 pulses at 20 Hz) was fully inhibited and the peak of response to HS at 20 Hz was inhibited by about 60% by the addition of Guan (3×10-5M). After treatment with PBA (1×10-8-1×10-7M), the peak of response to HS was significantly inhibited and sometimes completely by the addition of Guan. But when the concentration of PBA was increased to 1×10-6M or 1×10-5M, the reduction of the peak of response to HS by Guan became less concentration-dependent. Inhibitory effect of Guan on response to TS was also prevented by pretreatment with PBA (1×10-6-1×10-5M). On the other hand, after treatment with PBA (1×10-7M or 1×10-6M) methamphetamine (1×10-5M) fully restored the response to TS but scarcely restored the peak of response to HS in the presence of Guan. After the addition of methamphetamine, inhibitory effect of Guan on the peak response to HS was prevented soon and completely by washout of Guan. PBA seems to cause inhibition of Guan uptake at nerve endings. But after treatment with PBA the conduction of impulse to nerve endings seems to be partially blocked by the addition of Guan and methamphetamine does not seem to antagonized the conduction blocking activity induced by Guan.
