Bowman A, Drummond A H
Br J Pharmacol. 1984 Apr;81(4):665-74. doi: 10.1111/j.1476-5381.1984.tb16133.x.
Field stimulation of the non-adrenergic, non-cholinergic inhibitory nerves to the bovine isolated retractor penis muscle evoked a relaxation that was preceded by a rise in the tissue content of cyclic GMP. There was no change in the content of cyclic AMP. The selective cyclic GMP phosphodiesterase inhibitor, 2-o- propoxyphenyl -8- azapurin -6-one (M&B 22948), elevated the tissue's cyclic GMP content, and potentiated both the relaxation and the rise in cyclic GMP produced by inhibitory nerve stimulation. Sodium nitroprusside and an inhibitory factor extracted from the bovine retractor penis muscle mimicked the effects of inhibitory nerve stimulation in that they each produced relaxation associated with a selective rise in cyclic GMP concentration. Haemoglobin (in the form of erythrocyte haemolysate) and N- methylhydroxylamine , which are known to block guanylate cyclase, blocked the relaxation and the rise in cyclic GMP content produced by inhibitory nerve stimulation, inhibitory factor and sodium nitroprusside. Haemoglobin itself caused a rise in muscle tone and at the same time reduced the cyclic GMP content of the tissue. 8-Bromocyclic GMP, a permeant derivative of cyclic GMP, produced a relaxation of the muscle that, as expected, was not blocked by haemoglobin. Vasoactive intestinal polypeptide, prostaglandin E1 and forskolin each produced relaxation associated with a selective rise in cyclic AMP content. Their effects were not blocked by haemoglobin or N- methylhydroxylamine . It is concluded that inhibitory nerve stimulation in the bovine retractor penis muscle produces a relaxation that is mediated by cyclic GMP, although some substances relax the muscle without affecting cyclic GMP levels. The results are also compatible with the view that the extracts of muscle contain the inhibitory neurotransmitter.
对牛离体阴茎退缩肌的非肾上腺素能、非胆碱能抑制神经进行场刺激，可诱发肌肉松弛，此松弛之前组织中环鸟苷酸（cGMP）含量会升高。环磷酸腺苷（cAMP）含量无变化。选择性cGMP磷酸二酯酶抑制剂2 - o - 丙氧基苯基 - 8 - 氮杂嘌呤 - 6 - 酮（M&B 22948）可提高组织中的cGMP含量，并增强抑制神经刺激所产生的肌肉松弛及cGMP升高。硝普钠和从牛阴茎退缩肌中提取的一种抑制因子模拟了抑制神经刺激的作用，即它们各自产生与cGMP浓度选择性升高相关的肌肉松弛。已知可阻断鸟苷酸环化酶的血红蛋白（以红细胞溶血产物形式存在）和N - 甲基羟胺，可阻断抑制神经刺激、抑制因子和硝普钠所产生的肌肉松弛及cGMP含量升高。血红蛋白本身可引起肌张力升高，同时降低组织中的cGMP含量。8 - 溴环鸟苷酸是cGMP的一种可渗透衍生物，可使肌肉松弛，正如预期的那样，这种松弛不受血红蛋白的阻断。血管活性肠肽、前列腺素E1和福斯高林各自产生与cAMP含量选择性升高相关的肌肉松弛。它们的作用不受血红蛋白或N - 甲基羟胺的阻断。得出的结论是，牛阴茎退缩肌中的抑制神经刺激产生的肌肉松弛是由cGMP介导的，尽管有些物质可使肌肉松弛而不影响cGMP水平。这些结果也与肌肉提取物含有抑制性神经递质这一观点相符。
