Lau W A, Ventura S, Pennefather J N
Department of Pharmacology, Monash University, Clayton, Victoria, Australia.
J Auton Pharmacol. 1998 Dec;18(6):349-56. doi: 10.1046/j.1365-2680.1998.1860349.x.
Histochemical studies carried out on sections of rat and guinea-pig prostate glands revealed the presence of acetylcholinesterase- and noradrenaline-containing nerve fibres in the fibromuscular stroma. Positive staining for acetylcholinesterase but not for noradrenaline was also seen in the epithelium. Electrical field stimulation with trains of 0.5 ms pulses, dial setting of 60 V, delivered at 1-30 Hz for 10 s at 5 min intervals, was applied to nerve terminals within the rat and guinea-pig isolated prostate glands. The evoked contractions were frequency-dependent. Tetrodotoxin (1 microM) abolished contractions evoked by short pulse repetitive stimulation (trains of 20 0.5 ms pulses at 10 Hz every 100 s) in tissues from both species. The field stimulation-induced contractions of the prostatic smooth muscle were markedly attenuated by guanethidine (10 microM) and prazosin (0.1 and 1 microM) indicating that neurotransmission to the prostatic smooth muscle in both species is predominantly sympathetic and noradrenergic, and that noradrenaline released during field stimulation acts at postjunctional alpha1-adrenoceptors. Atropine (0.1 and 1 microM) caused a slight but significant reduction of the field stimulation-induced contractions of prostate smooth muscle from both the rat and the guinea-pig. In the guinea-pig, cholinesterase inhibition by physostigmine and neostigmine, both at 10 microM, enhanced the field stimulation-induced contractions of the prostatic smooth muscle. This enhancement was reversed by atropine (0.1 microM) but not by hexamethonium (0.1 mM). These data are compatible with some participation of acetylcholine, acting at muscarinic receptors, in neurotransmission to prostatic smooth muscle.
对大鼠和豚鼠前列腺切片进行的组织化学研究显示，在纤维肌基质中存在含乙酰胆碱酯酶和去甲肾上腺素的神经纤维。上皮细胞中也可见乙酰胆碱酯酶呈阳性染色，但去甲肾上腺素呈阴性染色。将间隔5分钟、以1 - 30赫兹频率施加10秒、脉宽0.5毫秒、电压设置为60伏的串刺激施加于大鼠和豚鼠离体前列腺内的神经末梢。诱发的收缩具有频率依赖性。河豚毒素（1微摩尔）可消除两种动物组织中短脉冲重复刺激（每100秒10赫兹的20个0.5毫秒脉冲串）诱发的收缩。胍乙啶（10微摩尔）和哌唑嗪（0.1和1微摩尔）可显著减弱电场刺激诱发的前列腺平滑肌收缩，表明两种动物中前列腺平滑肌的神经传递主要是交感神经和去甲肾上腺素能的，且电场刺激期间释放的去甲肾上腺素作用于节后α1 - 肾上腺素能受体。阿托品（0.1和1微摩尔）可使大鼠和豚鼠前列腺平滑肌的电场刺激诱发收缩略有但显著降低。在豚鼠中，毒扁豆碱和新斯的明（均为10微摩尔）抑制胆碱酯酶可增强电场刺激诱发的前列腺平滑肌收缩。这种增强作用可被阿托品（0.1微摩尔）逆转，但不能被六甲铵（0.1毫摩尔）逆转。这些数据表明乙酰胆碱作用于毒蕈碱受体，在前列腺平滑肌的神经传递中发挥了一定作用。
