Imura H, Nakao K, Yanaihara N, Katsuura G, Nakamura M
Neuroendocrinology. 1986;44(2):142-8. doi: 10.1159/000124637.
Leumorphin is a 29-amino-acid peptide derived from preproenkephalin B. Intracerebroventricular (i.c.v.) injection of leumorphin through an implanted cannula into the lateral ventricle of rats dose-dependently inhibited water intake induced by water deprivation, angiotensin II (AII) and carbachol. This effect was partially reversed by intraperitoneal injection of naloxone, an opiate antagonist. Naloxone alone rather attenuated water intake. The antidipsogenic effect of leumorphin was very potent: 0.6 pmol of the peptide significantly inhibited AII-induced drinking. Dynorphin 1-17 was almost as potent as leumorphin in inhibiting drinking, whereas alpha-neo-endorphin and leucine-enkephalin (Leu-enkephalin) were far less effective. Leumorphin given i.c.v. dose-dependently enhanced eating and this effect was abolished by naloxone. Dynorphin was as potent as leumorphin in inducing feeding, whereas alpha-neo-endorphin and Leu-enkephalin had no significant activity when 6 nmol was used. General activity measured by an Automex was enhanced by i.c.v. injection of leumorphin but required larger amounts of the peptide than did drinking behavior. The very potent and specific effects of leumorphin and dynorphin on drinking behavior suggest that the antidipsogenic activity of these peptides is of physiological significance like their effect on feeding.
亮啡肽是一种由前脑啡肽原B衍生而来的含29个氨基酸的肽。通过植入的套管向大鼠侧脑室内注射亮啡肽，剂量依赖性地抑制了由水剥夺、血管紧张素II（AII）和卡巴胆碱诱导的饮水。腹腔注射阿片拮抗剂纳洛酮可部分逆转这种作用。单独使用纳洛酮反而会减弱饮水。亮啡肽的抗饮水作用非常强：0.6皮摩尔的该肽就能显著抑制AII诱导的饮水。强啡肽1-17在抑制饮水方面几乎与亮啡肽一样有效，而α-新内啡肽和亮氨酸脑啡肽的效果则差得多。脑室内注射亮啡肽剂量依赖性地增加进食，且这种作用被纳洛酮消除。强啡肽在诱导进食方面与亮啡肽一样有效，而当使用6纳摩尔的α-新内啡肽和亮氨酸脑啡肽时，它们没有显著活性。通过自动运动仪测量的一般活动通过脑室内注射亮啡肽而增强，但与饮水行为相比，需要更大剂量的该肽。亮啡肽和强啡肽对饮水行为的非常强且特异的作用表明，这些肽的抗饮水活性与其对进食的作用一样具有生理意义。
