Najbar-Kaszkiel A T, Di Iulio J L, Li C G, Rand M J
Department of Medical Laboratory Science, Royal Melbourne Institute of Technology, Vic., Australia.
Eur J Pharmacol. 1997 Oct 22;337(2-3):251-8. doi: 10.1016/s0014-2999(97)01270-3.
Excitatory and inhibitory transmitter systems were investigated in strips of prostate glands from rats, guinea pigs, pigs and rabbits. In strips from all species, electrical field stimulation (1 ms pulses at 1-30 Hz for 10 s) produced frequency-dependent contractions which were abolished by tetrodotoxin (1 microM). In strips from rats, guinea pigs and rabbits, contractions were reduced by prazosin (1 microM), guanethidine (10 microM) and atropine (2 microM), indicating the presence of noradrenergic and cholinergic mechanisms. However, the smooth muscle in the pig prostate appears to have a non-(nor)adrenergic non-cholinergic (NANC) excitatory innervation for which the transmitter was not identified. When noradrenergic and cholinergic mechanisms were blocked by guanethidine and atropine, respectively, and tone was raised with noradrenaline or methoxamine, field stimulation produced relaxations only in strips of rabbit prostate, and these were greatly reduced by N(G)-nitro-L-arginine methyl ester (L-NAME, 100 microM), providing functional evidence for a nitrergic relaxant innervation. In accord with this, nitric oxide (NO) synthase activity was considerably higher in rabbit than in rat or pig prostates.
对大鼠、豚鼠、猪和兔的前列腺条带中的兴奋性和抑制性递质系统进行了研究。在所有物种的条带中，电场刺激（1 - 30 Hz的1 ms脉冲，持续10 s）产生频率依赖性收缩，这种收缩被河豚毒素（1 μM）消除。在大鼠、豚鼠和兔的条带中，哌唑嗪（1 μM）、胍乙啶（10 μM）和阿托品（2 μM）可使收缩减弱，表明存在去甲肾上腺素能和胆碱能机制。然而，猪前列腺中的平滑肌似乎有一种非（去甲）肾上腺素能非胆碱能（NANC）兴奋性神经支配，但尚未确定其递质。当分别用胍乙啶和阿托品阻断去甲肾上腺素能和胆碱能机制，并用去甲肾上腺素或甲氧明提高张力时，电场刺激仅在兔前列腺条带中产生舒张作用，且这些舒张作用被N（G）-硝基-L-精氨酸甲酯（L-NAME，100 μM）大大减弱，这为氮能舒张性神经支配提供了功能证据。与此一致的是，兔前列腺中的一氧化氮（NO）合酶活性明显高于大鼠或猪的前列腺。
