[In vivo effects of 24R,25-dihydroxyvitamin D3 on kidney alkaline phosphatase and gamma-glutamyltransferase of hypophysectomized rats].

The effects of 24R, 25-dihydroxyvitamin D3 (24, 25 (OH)2 D3) on alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT) and acid phosphatase (ACP) activities were investigated on renal cortex of hypophysectomized (Hx) rats. ALP activity was increased by +27, +56 and +60% as compared to controls respectively 3, 6 and 12 h after intraperitoneal administration of the secosteroid (10 pmoles/100 g body weight). Stimulations of GGT activity began only after 6 h (+30%) and 12 h (+ 46%).

Evidence that growth hormone stimulates protein kinase C activity in isolated rat hepatocytes.

The mechanism of action of growth hormone (GH) is not known, although indirect evidence suggests that protein kinase C (PKC) might play an important role in the insulin-like actions of GH. In this investigation, we directly examined the effects of GH relative to those of insulin on PKC activity in isolated rat hepatocytes. Human GH (10(-7) mol/L) significantly increased the activity of PKC in both cytosolic and particulate fractions.

[In vitro effects of 24R,25-dihydroxyvitamin D3 on alkaline phosphatase and gamma-glutamyltransferase in the kidney of hypophysectomized rats].

The effects of 24R,25-dihydroxyvitamin D3 (24,25-(OH)2D3 on alkaline phosphatase (PAL), gamma-glutamyltransferase (GGT) and acid phosphatase (PAC) activities were investigated on renal cortex slices of hypophysectomized rats. Indeed after hypophysectomy renal 24,25-(OH)2D3 production was increased and renal PAL and GGT activities were decreased. After 5h incubation with physiological concentrations (0.

[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 vitro stimulation of alkaline phosphatase and gamma- glutamyltransferase in the kidney of hypophysectomized rat by the mixture of 1,25 and 24,25 dihydroxycholecalciferols].

The present study was undertaken to investigate the in vitro effects of two cholecalciferol metabolites 1,25(OH)2CC and 24,25(OH)2CC on the renal cortex alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT) and acid phosphatase (ACP) activities in hypophysectomized rats. We found that both 1,25-CC and 24,25-CC stimulated ALP and GGT. An additive effect was obtained on ALP and GGT after incubation with one with the other metabolites.