ACTION OF NITRIC OXIDE ON THE INTERNAL URETHRAL SPHINCTER FUNCTION

本研究探讨一氧化氮对尿道内括约肌功能的影响。用聚氨酯麻醉雌性大鼠。结扎膀胱颈，独立测量膀胱内压和尿道内压。在静脉给药潘克溴铵消除尿道横纹肌活动的条件下，连续记录动脉给药前后节律性等容量膀胱收缩时膀胱和尿道压力。使用的药物有合成一氧化氮的l -精氨酸、抑制l -精氨酸合成一氧化氮的L-NMMA、L-NAME和抑制可溶性胍基环化酶活化的亚甲基蓝。在给药前，出现有节奏的膀胱收缩并伴有尿道松弛。给予l -精氨酸可降低尿道压力。L-NMMA、L-NAME和亚甲基蓝对膀胱节律性收缩时内尿道括约肌松弛有抑制作用。一氧化氮/循环GMP通路似乎在尿道内括约肌松弛中起重要作用。研究了l -精氨酸和亚甲基蓝对大鼠膀胱充血和电刺激脑桥排尿中枢等容量膀胱收缩的影响。在膀胱填充反应的等容量膀胱收缩中，l -精氨酸使膀胱容量增加，膀胱收缩压力降低。亚甲基蓝对l -精氨酸有抑制作用。在电刺激脑桥排尿中枢引起的等容量膀胱收缩中，亚甲基蓝使膀胱收缩压力和膀胱收缩持续时间增加。一氧化氮/循环GMP通路似乎对膀胱活动有一定作用。少

The present study was performed to investigate action of nitric oxide on the internal urethral sphincter function. Female rats were anesthetzed with urethane. The bladder neck was ligated in order to measure independently intravesical pressure and internal urethral pressure. Under condition of abolishment of the urethral striated muscle activity by the intravenous administration of pancronium bromide, the bladder and urethral pressure were continuosly recorded during rhythmic isovolumetric bladder contractions before and after intraarterial administration of the following drugs. Used drugs were L-arginine from which nitric oxide is synthetized, L-NMMA,L-NAME which inhibit the synthesis of nitric oxide from L-arginine, and methylene blue which inhibits the activation of soluble guanylyl cyclase. Before the administration of each drug, rhythmic bladder contractions with concomitant urethral relaxations were occurred. Administration of L-arginine produced a decrese in urethral pressure. A … More dministration of L-NMMA,L-NAME and methylene blue produced an inhibition of the internal urethral sphincter relaxation during rhythmic bladder contractions. The nitric oxide/cyclic GMP pathway seems to take an important role for the internal urethral sphincter relaxation.Decerebrate dogs were used to examine the effect of L-arginine and methylene blue on the isovolumetric bladder contractions in response to bladder fillig and electrical stimulation of pontine micturition center. In the isovolumetric bladder contractions in response to bladder filling, L-arginine produced an increase in bladder capacity and a decrease in bladder contraction pressure. Methylene blue produced an inhibition of effect of L-arginine. In the isovolumetric bladder contractions in response to electrical stimulation of pontine micturition center, methylene blue produced an increase in the bladder contraction pressure and duration of bladder contraction. The nitric oxide/cyclic GMP pathway seems to take certain role for bladder activity. Less