1,721,005 research outputs found
Somatostatin, somatostatin analogs and somatostatin receptor dynamics in the biology of cancer progression.
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Effect of the acid-labile subunit on the binding of insulin-like growth factor (IGF)-binding protein-3 to [125I]IGF-I. J.Clin.Endocrinol.Metab. 80 (4):1318-1324, 1995.
No full textSerum IGF-I concentration is positively associated with 25-hydroxyvitamin D level and increases upon treatment with vitamin D.
No full textDecreased acid-labile subunit (ALS) levels by endotoxin in vivo and by interleukin-1beta in vitro
No full textThe production by the liver of the three subunits of the growth hormone (GH)-dependent 150 kDa complex (IGF-I, IGF-binding protein-3 and acid-labile subunit or ALS) is primarily under the control of GH. Recent data have shown that, besides GH, endotoxin (LPS) and cytokines may regulate the liver IGF-I gene. To investigate the potential regulation of ALS by LPS, we measured serum ALS by immunoblot, 5 and 10 h after IP injection of LPS (250 or 750 microg/100 g BW vs saline), in 4-week-old female Wistar rats (four per group). Ten hours after injection, serum ALS levels were reduced by 57% (delta%) with the lower dose (P<0.05) and by 81% with the higher dose (P<0.01) by comparison with saline-treated rats. The decrease in ALS levels in response to LPS was not prevented by exogenous GH. To investigate the role of interleukin (IL)-1beta in the regulation of ALS, primary cultured rat hepatocytes were exposed to increasing concentrations of IL-1beta. Cell exposure to IL-1beta markedly decreased both basal and GH-stimulated ALS levels (-70%; P<0.01) in a dose-dependent fashion, with the half-maximal inhibitory effect at concentrations of 0.1 ng/ml. Our results show that endotoxin induces a rapid decline in circulating ALS that is potentially mediated through IL-1beta. By limiting the formation of the 150 kDa complex, this reduction in circulating ALS might contribute to the rapid decline in serum IGF-I observed in sepsis
IGF-I production by adult rat hepatocytes is stimulated by transforming growth factor alfa and trasforming growth factor beta1
No full textThe clinical-molecular interface of somatostatin, dopamine and their receptors in pituitary pathophysiology
No full textSomatostatin-induced activation and up-regulation of N-methyl-D-aspartate receptor function: mediation through calmodulin-dependent protein kinase II, phospholipase C, protein kinase C, and tyrosine kinase in hippocampal noradrenergic nerve endings.
No full textSomatostatin receptors and glutamate NMDA receptors coexist and interact in hippocampal noradrenergic axon terminals. Activation of somatostatin receptors was previously found to positively influence the function of NMDA receptors regulating norepinephrine release. The somatostatin receptors involved were pharmacologicaaly characerized as sst type, in experiments in Mg2+-free solutions.Inthe present work, we first confirm the pharmacology of these receptors using selective sst5 ligands in Mg2+-containing solutions. Moreover, we show by western blot that the sst5 protein exists on purified hippocampal synaptosomal membrames. We here investigate the pathways connecting the two receptors using as a functional response the release of norepinephrine from rat hippocampal synaptosomes in superfusion. The release of norepinephrine evoked by somatostatin-14 plus NMDA/glycine, in presence of external Mg2+ ions, was partly prevented by the protein kinase C inhibitor GF109203X and by the non-receptor tyrosine kinase (Src) inhibitors PP2 and lavendustin A; it was largely and almost totally abolished by the phospholipase C inhibitor U73122 and by the Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93, respectively; it was unaffected by the protein kinase A inhibitor H89. The norepinephrine release evoked by somatostatin-14/NMDA/glycine was inhibited when anti-phosphotyrosine antibodies had been entrapped inside the synaptosomes. Entrapping the recombinant activated tyrosine kinase pp60c-Src strongly potentiated the release of norepinephrine elicited by NMDA/glycine in Mg2+-free medium, but failed to permit NMDA receptor activation in presence of external Mg2+ ions. The results suggest the involvement of CaMKII in the sst5 receptor-mediated activation of NMDA receptors in presence of Mg2+ and of the PLC/PKC/Src pathway in the upregulation of the ongoing NMDA receptor activity
Effects of alpha-interferon on insulin-like growth factor-I, insulin-like growth factor-II and insulin-like growth factor binding protein-3 secretion by a human lung cancer cell line in vitro.
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