To assess the role of protein kinase C and cAMP on the calcitonin-induced alteration of phosphate accumulation by renal tubular cells, the effects of phorbol esters, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), and DBcAMP on the phosphate accumulation in LLC-PK1 cells were investigated. Calcitonin stimulated phosphate accumulation with a concomitant increase in cAMP production. Phorbol ...

Human Sertoli cell parameters, namely lactate, estradiol-17 beta, and transferrin production, were determined after a 24-hour incubation with either human follicle stimulating hormone (FSH) or dbcAMP in the presence or absence of testosterone plus a phosphodiesterase inhibitor (1-methyl-3-isobutylxanthine; MIX). Testicular tissues were obtained from 10 young patients (mean age, 29 years); using...

Hepatocyte growth factor (HGF) secreted from human promyelocytic leukemia cell line, HL-60, is indistinguishable from HGF in human plasma and its release is significantly stimulated by 1 2-0-tetradecanoylphorbol-I 3-acetate (TPA), a differentiation-inducer of HL-60 cells into monocytes/macrophages (Nishino T et al: Biochem Biophys Res Commun 181 :323, 1991). TPA stimulated HGF release from the ...

HTC cell variants chosen for their lack of tyrosine aminotransferase (EC 2.6.1.5) (TAT) induction by glucocorticoids were tested for interrelated effects on other glucocorticoid responses: TAT induction by dibutyryl cyclic AMP (dBcAMP) +/- dexamethasone, glutamine synthetase (GS) induction, cyclic nucleotide phosphodieterase (PDE) suppression, inhibition of alpha-aminoisobutyric acid (AIB) upta...

The effects of three calmodulin antagonists on rat parotid amylase release were investigated in vitro using a dispersed acinar cell preparation. The potent calmodulin antagonists, trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), inhibited both 1 microM isoproterenol (ISO)- and 1 mM dibutyryl cyclic AMP (DBcAMP)-stimulated amylase release in a dose-dependent ma...

Cholinergic properties of the SN56.B5.G4 cell line derived from the fusion of neurons of the mouse postnatal day 21 septum and the murine neuroblastoma cell line N18TG2 were investigated and correlated with morphological differentiation. In basal serum-containing growth medium, few cells developed neurites. Neurite extension occurred in cells grown for 2 d with forskolin or dibutyryl cAMP (dbcA...

Exposure of CHO-K1 cells in vitro to dibutyryl adenosine cyclic 3',5'-monophosphate (DBcAMP) plus testololactone produces a rapid, reversible antagonism of ligand-induced collection of initially dispersed concanavalin A (Con A) binding sites into a caplike mass. Morphologically, as Con A capping occurs, the cells become less spread and then round completely. With prolonged Con A exposure, cells...

The adaptive responses to hypoxia are mediated by hypoxia-inducible factor 1 alpha (HIF1α). Its role, however, in regulating steroidogenesis remains poorly understood. We examined the role of hypoxia and HIF1α in regulating steroid acute regulatory protein (STAR) expression and steroidogenesis in immortalized (KK1) mouse granulosa cells under progressively lowering O2 concentrations (20%, 15%, ...