Implication of leumorphin in inhibitory control of vasopressin secretion in conscious rats

Takayuki Yamada, Kazuwa Nakao, Hiroshi Itoh, Narito Morii, Shozo Shiono, Makoto Sakamoto, Akira Sugawara, Yoshihiko Saito, Masashi Mukoyama, Hiroshi Arai, Hiroo Imura

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The effects of leumorphin, a K-agonist derived from proenkephalin B (neoendorphin and dynorphin precursor), on vasopressin secretion were studied under basal and stimulated conditions in conscious, unrestrained rats. Intracerebroventricular injection of leumorphin (60 or 600 pmol) significantly inhibited basal vasopressin secretion. The vasopressin response induced by intracerebroventricular injection of angiotensin II (100 pmol) was significantly suppressed, hi a dose-dependent fashion, by the simultaneous intracerebroventricular injection of leumorphin (6, 60, or 600 pmol). Intravenous pretreatment with naloxone (0.5 mg/kg body weight) diminished the inhibitory action of leumorphin (60 pmol) on vasopressin secretion. Moreover, naloxone (0.5 mg/kg body weight) prolonged the vasopressin secretion induced by intracerebroventricular injection of angiotensin II (100 pmol). These results indicate that leumorphin possesses a potent inhibitory effect on vasopressin secretion and that, alone or in combination with other endogenous opioid peptides, it plays an important role hi the control of vasopressin secretion.

Original languageEnglish
Pages (from-to)I-80-I-83
JournalHypertension
Volume11
Issue number2
Publication statusPublished - 1988 Feb
Externally publishedYes

    Fingerprint

Keywords

  • Angiotensin II
  • Naloxone
  • Opioid peptides
  • Vasopressin

ASJC Scopus subject areas

  • Internal Medicine

Cite this

Yamada, T., Nakao, K., Itoh, H., Morii, N., Shiono, S., Sakamoto, M., Sugawara, A., Saito, Y., Mukoyama, M., Arai, H., & Imura, H. (1988). Implication of leumorphin in inhibitory control of vasopressin secretion in conscious rats. Hypertension, 11(2), I-80-I-83.