Moser A, Reavill C, Jenner P, Marsden C D, Cramer H
Exp Brain Res. 1986;62(3):567-71. doi: 10.1007/BF00236035.
The effect of somatostatin-14 (SRIF) on dopamine-sensitive adenylate cyclase in caudate-putamen pellets was studied in naive female rats, and in rats with chemical lesions of the nigrostriatal dopaminergic tract produced by injection of 6-hydroxydopamine, or of the caudate-putamen itself produced by injection of kainic acid 3 week earlier. In unlesioned rats somatostatin at a concentration of 10(-7) moles/l inhibited adenylate cyclase activation by submaximal concentrations of dopamine, increasing the apparent Km but not altering Emax. In 6-hydroxydopamine lesioned rats somatostatin no longer influenced adenylate cyclase activity, whereas in kainic acid lesioned rats somatostatin still increased the apparent Km for dopamine activation. The effect of somatostatin in untreated and lesioned rats is compatible with a partial competitive antagonism to dopamine. Although the data from the lesioned rats present preliminary results, the dose response characteristics and the effects in lesioned animals suggest a more complex interaction, possibly by binding of somatostatin to an inhibitory subunit of regulatory adenylate cyclase components.
在未处理的雌性大鼠、经6-羟基多巴胺注射造成黑质纹状体多巴胺能通路化学损伤的大鼠，或3周前经 kainic 酸注射造成尾状核-壳核自身损伤的大鼠中，研究了生长抑素-14（SRIF）对尾状核-壳核组织块中多巴胺敏感性腺苷酸环化酶的影响。在未损伤的大鼠中，浓度为10^(-7) 摩尔/升的生长抑素可抑制亚最大浓度多巴胺对腺苷酸环化酶的激活作用，增加表观 Km 值但不改变 Emax。在6-羟基多巴胺损伤的大鼠中，生长抑素不再影响腺苷酸环化酶活性，而在 kainic 酸损伤的大鼠中，生长抑素仍会增加多巴胺激活的表观 Km 值。生长抑素在未处理和损伤大鼠中的作用与对多巴胺的部分竞争性拮抗作用相符。尽管来自损伤大鼠的数据是初步结果，但剂量反应特征以及在损伤动物中的作用表明存在更复杂的相互作用，可能是生长抑素与调节性腺苷酸环化酶成分的抑制亚基结合所致。
