López-Sañudo S, Arilla E
Department of Biochemistry and Molecular Biology, Medical School, University of Alcalá, Madrid, Spain.
Brain Res. 1993 Jun 18;614(1-2):171-7. doi: 10.1016/0006-8993(93)91031-m.
DL-Propranolol (PRO), a beta-adrenergic blocking agent, and the neuropeptide somatostatin (SS) have central nervous system depressant and anticonvulsive properties. To investigate a possible relationship between these two components, we studied the influence of PRO and DL-isoproterenol (ISO), a beta-adrenergic agonist, on the somatostatinergic system in the rat frontoparietal cortex. The short- (5 h) and long-term (14 days) administration of ISO (5 mg/kg, intraperitoneally (i.p.)), or of PRO (10 mg/kg, i.p.) did not affect somatostatin-like immunoreactivity (SLI) content in the frontoparietal cortex of male Wistar rats. Both short- and long-term ISO administration decreased the number of specific [125I]Tyr11-SS receptors in synaptosomes from frontoparietal cortex (31%, P < 0.05, and 26%, P < 0.02, after short- and long-term administration, respectively) without changing the affinity constant. This decrease in the number of [125I]Tyr11-SS receptors was not due to a direct effect of ISO on these receptors since no decrease in binding was produced by high concentrations of ISO (10(-5) M) when added in vitro. This decrease could be blocked by pretreatment with PRO. Short- and long-term administration of PRO alone produced an increase in the [125I]Tyr11-SS binding in frontoparietal cortex (26%, P < 0.02, and 40%, P < 0.001, after short- or long-term administration, respectively) without changing the affinity constant.
DL-普萘洛尔（PRO）是一种β-肾上腺素能阻滞剂，神经肽生长抑素（SS）具有中枢神经系统抑制和抗惊厥特性。为了研究这两种成分之间的可能关系，我们研究了PRO和β-肾上腺素能激动剂DL-异丙肾上腺素（ISO）对大鼠额顶叶皮质生长抑素能系统的影响。短期（5小时）和长期（14天）腹腔注射（i.p.）ISO（5mg/kg）或PRO（10mg/kg）对雄性Wistar大鼠额顶叶皮质中生长抑素样免疫反应性（SLI）含量没有影响。短期和长期给予ISO均可降低额顶叶皮质突触体中特异性[125I]Tyr11-SS受体的数量（短期和长期给药后分别降低31%，P<0.05和26%，P<0.02），而不改变亲和常数。[125I]Tyr11-SS受体数量的减少不是由于ISO对这些受体的直接作用，因为在体外加入高浓度ISO（10^(-5)M）时，结合没有减少。这种减少可被PRO预处理阻断。单独短期和长期给予PRO可使额顶叶皮质中[125I]Tyr11-SS结合增加（短期或长期给药后分别增加26%，P<0.02和40%，P<0.001），而不改变亲和常数。
