Membrane-mediated inhibition of corticosterone on the release of arginine vasopressin from rat hypothalamic slices.
The arginine vasopressin (AVP) released from the hypothalamic slices containing paraventricular and supraoptic nuclei of Sprague-Dawley rats sectioned with vibratome and incubated in static microchambers was measured by radioimmunoassay. The effect of bovine serum albumin-conjugated corticosterone (B-BSA) on the AVP release was investigated. The results were as follows: (1) B-BSA, within 20 min, significantly inhibited AVP release in a dose-dependent manner from 10(-7) to 10(-4) mol/l. (2) RU38486 (10(-4)-10(-3) mol/l) could partially block the inhibitory effect of B-BSA although it by itself did not change the AVP release. (3) With the elevation of Ca2+ concentration in the incubation medium, the AVP release was increased and the inhibitory effect of B-BSA enhanced; while in the absence of Ca2+, the AVP release decreased and the effect of B-BSA attenuated. (4) The inhibitory effect of B-BSA was enhanced in the presence of neomycin which itself had no influence on AVP release. These results indicated that the inhibitory effect of corticosterone is rapid and membrane-mediated which is non-genomic rather than classical genomic, and that the extracellular Ca2+ play a role in this rapid inhibitory effect.
Liu
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X
Department of Physiology, Second Military Medical University, Shanghai, People's Republic of China.
Chen
Y Z
YZ
D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000502:physiology; D003345:Corticosterone / Q000037:antagonists & inhibitors* / Q000737:chemistry; D003470:Culture Media; D005260:Female; D016678:Genome; D006727:Hormone Antagonists / Q000494:pharmacology; D007031:Hypothalamus / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D015735:Mifepristone / Q000494:pharmacology; D009355:Neomycin / Q000494:pharmacology; D009490:Neurosecretory Systems / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000737:chemistry*
D003470:Culture Media; D006727:Hormone Antagonists; D001127:Arginine Vasopressin; D012710:Serum Albumin, Bovine; D015735:Mifepristone; D009355:Neomycin; D002118:Calcium; D003345:Corticosterone