Okuma Y, Yokotani K, Osumi Y
Department of Pharmacology, Kochi Medical School, Japan.
Life Sci. 1996;59(15):1217-25. doi: 10.1016/0024-3205(96)00445-6.
Intracerebroventricular (i.c.v.) administration of bombesin (0.1, 1.0, 10.0 nmol/animal) in urethane-anesthetized rats induced long-lasting and dose dependent increases in plasma levels of adrenaline and noradrenaline. These effects of bombesin were inhibited by i.c.v. pretreatment with indomethacin (50-500 micrograms/animal), while the same dose of indomethacin by the intravenous route was without effect. The bombesin-induced increases in plasma levels of catecholamines were also inhibited by i.c.v. pretreatment with diclofenac (100-500 micrograms/animal), a cyclooxygenase inhibitor other than indomethacin. I.c.v. administration of thyrotropin releasing hormone (TRH) (10 nmol/animal) also induced increases in plasma levels of adrenaline and noradrenaline, however, these increases were not modified by i.c.v. pretreatment with indomethacin. The present results suggest that the bombesin-induced increases in plasma levels of catecholamines are probably due to prostaglandins synthetized in the brain with this neuropeptide. Furthermore, it is likely that prostaglandins are not always involved in central activation of sympatho-adrenomedullary system by other brain neuropeptides.
在氨基甲酸乙酯麻醉的大鼠中，脑室内（i.c.v.）注射蛙皮素（0.1、1.0、10.0 nmol/只动物）可引起血浆肾上腺素和去甲肾上腺素水平持久且剂量依赖性的升高。蛙皮素的这些作用可被吲哚美辛（50 - 500微克/只动物）脑室内预处理所抑制，而相同剂量的吲哚美辛经静脉途径给药则无作用。蛙皮素引起的儿茶酚胺血浆水平升高也可被双氯芬酸（100 - 500微克/只动物）脑室内预处理所抑制，双氯芬酸是一种不同于吲哚美辛的环氧化酶抑制剂。脑室内注射促甲状腺激素释放激素（TRH）（10 nmol/只动物）也可引起血浆肾上腺素和去甲肾上腺素水平升高，然而，这些升高不受吲哚美辛脑室内预处理的影响。目前的结果表明，蛙皮素引起的儿茶酚胺血浆水平升高可能是由于与这种神经肽一起在脑内合成的前列腺素所致。此外，前列腺素可能并不总是参与其他脑内神经肽对交感 - 肾上腺髓质系统的中枢激活作用。
