Inhibitory effect of galanin on dopamine-induced enhanced vasopressin secretion in rat neurohypophyseal tissue cultures.
The effect of galanin (GAL) on vasopressin (VP) secretion was studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP content of the supernatant was determined by radioimmunoassay (RIA) after a 1- or 2-h incubation. A significantly decreased content of VP was detected following the administration of 10(-6)-10(-9) M doses of GAL. Dopamine (DA) and the DA-active drugs apomorphine (APM) and Pro-Lys-Gly (PLG) (10(-6) M in each medium) increased the VP level of NH tissue cultures. This VP concentration elevation could be blocked by the administration of GAL together with DA, APM or PLG. The DA-blocking effect of GAL was prevented by previous treatment with the GAL receptor antagonist galantid (M15). The results indicate that VP release is directly influenced by the GAL-ergic system. The GAL-ergic control of VP secretion from NH tissue in rats can occur independently of the hypothalamus, at the level of the posterior pituitary.
Gálfi
M
M
Department of Biology, Faculty of Juhász Gyula Teacher Training College, University of Szeged, Szeged, Hungary. galfi@jgyt.u-szeged.hu
Baláspiri
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L
Tóth
R
R
Pávó
I
I
László
F
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Morschl
E
E
Varga
Cs
C
László
F A
FA
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D046508:Culture Techniques; D004298:Dopamine / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D019004:Galanin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008297:Male; D010904:Pituitary Gland, Posterior / Q000187:drug effects* / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D018013:Receptors, Neuropeptide / Q000037:antagonists & inhibitors; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology; D014667:Vasopressins / Q000378:metabolism*
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D018013:Receptors, Neuropeptide; D014667:Vasopressins; C074975:galantide; D013373:Substance P; D019004:Galanin; D001058:Apomorphine; D004298:Dopamine