Participation of opioid peptide (beta-endorphin) and norepinephrine in the control of compound 48/80-induced hypovolemic thirst in the rats.
1. Subcutaneous (s.c.) administration of compound 48/80 elicited the increases of water intake, plasma beta-endorphin-like immunoreactivity, hypothalamic 3-methoxy-4-hydroxyphenylethyleneglycol sulfate and Hct in the rats. 2. The s.c. pretreatment of naloxone reduced the compound 48/80-induced water intake but had no effects on other variables. 3. Intracerebroventricular (i.c.v.) injection of naloxone attenuated the compound 48/80- and i.c.v. injected angiotensin II (ANG II)-induced water intake. 4. The hypothalamic norepinephrine metabolism was increased by s.c. injection of compound 48/80 but not by i.c.v. ANG II. 5. The present data suggest the possible involvement of opioid peptide (beta-endorphin) on the compound 48/80- and ANG II-induced thirst. However, it is uncertain whether hypothalamic norepinephrine is involved in the hypovolemic thirst mediated via stimulation of renin-angiotensin system.
Izumi
H
H
Department of Physiology, Tohoku University School of Dentistry, Sendai, Japan.
D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001810:Blood Volume / Q000502:physiology*; D002395:Catecholamines / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007276:Injections, Intraventricular; D007279:Injections, Subcutaneous; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000378:metabolism; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology; D009638:Norepinephrine / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013894:Thirst / Q000187:drug effects*; D001615:beta-Endorphin / Q000502:physiology*; D003189:p-Methoxy-N-methylphenethylamine / Q000008:administration & dosage / Q000494:pharmacology*
D002395:Catecholamines; D000804:Angiotensin II; D009270:Naloxone; D003189:p-Methoxy-N-methylphenethylamine; D008734:Methoxyhydroxyphenylglycol; D001615:beta-Endorphin; D009638:Norepinephrine