[In vitro effects of 1,25-dihydroxycholecalciferol on alkaline phosphatase and gamma-glutamyltransferase activity in hypophysectomized rats].
Effects in vitro of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) on alkaline phosphatase (PAL), gamma-glutamyltransferase (gamma-GT) and acid phosphatase (PAC) activities were investigated on renal cortex from hypophysectomized rats. In these animals the biosynthesis of 1,25-(OH)2D3 and the specific activities of kidney PAL and gamma-GT were decreased. The course of these effects was determined from 45 min to 8 h. In the presence of 1,25-(OH)2D3 (2 x 10(-6) M) a delayed (5h) but simultaneous stimulation of the three enzymes was observed. It reached a maximum at 6h and disappeared at 8h. The dose-response relation was studied at 6h. In the presence of 1,25-(OH)2D3 (5 x 10(-7) M), the three enzymes were activated. The effect was maximal at 10(-6) M; it was +22% for PAL, +17% and +15% respectively for gamma-GT and PAC compared with controls. Cycloheximide suppressed the induction of PAL but not of gamma-GT activity. The effects of the secosteroid on renal enzymes seems to be a pharmacological more than a physiological one.
Laboratoires de Physiologie et de Biochimie appliquée (CHU), UFR des Sciences Médicales et Pharmaceutiques, Angers, France.
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Prelot
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Do
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Planchenault
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A
Girault
D000135:Acid Phosphatase / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D004347:Drug Interactions; D013006:Growth Hormone / Q000494:pharmacology; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000187:drug effects / Q000201:enzymology; D010902:Pituitary Gland / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D013006:Growth Hormone; D003513:Cycloheximide; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D002117:Calcitriol
Effets in vitro du 1,25-dihydroxycholecalciferol sur la phosphatase alcaline et la gamma-glutamyltransferase du rein de rat hypophysectomisé.