alpha-MSH effects on novelty-induced defecation, plasma 11-OHCS and whole brain catecholamines in hypophysectomized rats.
The effect of hypophysectomy on novelty-induced defecation was found to be inhibitory in nature, but this effect was reversed by treatment with alpha-MSH. MSH-treated hypox rats maintained, over days, novelty-induced defecation and showed a significant elevation in plasma 11-OHCS levels, compared with the levels of control-injected counterparts. MSH treatment also reduced over Days 1 to 5 the whole brain DA and whole brain NE levels in hypox animals. Control-treated hypox rats, however, showed an increase in brain NE concentration which was significantly reduced by MSH treatment. Sham-hypox animals also sustained novelty-induced defecation after MSH treatment but did not show a significant rise in plasma 11-OHCS level. Whole brain DA and whole brain NE levels in sham-hypox rats were also reduced significantly by MSH treatment. The behavioral maintenance of defecation in hypox and sham-hypox rats seem to be concomitant with significant reductions in whole brain catecholamines.
D015062:11-Hydroxycorticosteroids / Q000097:blood*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D002395:Catecholamines / Q000378:metabolism*; D003672:Defecation / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism; D007016:Hypophysectomy; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats
D015062:11-Hydroxycorticosteroids; D002395:Catecholamines; D009074:Melanocyte-Stimulating Hormones; D004298:Dopamine; D009638:Norepinephrine