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The biological activities of IGF-I and ?II are mediated mainly by the type 1 IGF receptor (IGF 1R) and controlled by their interaction with soluble proteins, the IGF binding proteins (IGFBPs). Although there is a growing body of evidence that some IGFBPs may be cell surface-bound, published data concerning cell association of IGFBP-1 are scarce and none of them concern placental cells. The cell membranes used in this study were isolated from term human placenta. Detergent-solubilized membranes were shown to contain two types of IGF binding structures that were separated by gel filtration on a Sephadex G-100 column. Proteins in the first peak were eluted at V0(Mr>100 kD) and they bound IGF-I with greater specificity and affinity than IGF-II and insulin. Most likely, they represented the IGF 1R. Small proteins (Mr?45 kD) were eluted with the membrane proteins in the second maximum. They were able to bind IGF-I and IGF-II, but not insulin. The identity of these proteins was shown to be IGFBP-1 on the basis of their reaction with specific anti-IGFBP-1 antibodies. To the best of our knowledge, the existence of IGFBP-1 associated with human placental cell membranes has not been reported in the literature before. Colocalisation of IGFBP-1 with IGF 1R in cell membranes could provide efficient modulation of IGF 1R receptor-ligand interactions.

The insulin-like growth factor (IGF)/IGF-binding protein (IGFBP) system was investigated in ejaculates from thirty men aged 23-46 years. Mean ejaculate volume was 3.3 mL (range 1-6 mL). Viscosity was increased moderately in six samples and greatly in four more. The number of motile sperm (0-165 million/mL; mean 49; median 39) was highly correlated with total number (P < 0.001). Concentrations of IGF-I and -II determined by displacement radioimmunoassay were positively correlated (P = 0.001). IGF-I ranged from 2.7 to 29.7 nmol/L (mean 9.6; median 6.5) and increased with viscosity. IGF-II ranged from 5.7 to 39.0 nmol/L (mean 16.0; median 13.5). IGFBP-2 and putative IGFBP-4 were detected by autoradiography of ligand blots after polyacrylamide gel electrophoresis. These binding proteins were stable in ejaculates stored at -18 ?C with protease inhibitors and remained associated with higher molecular weight complexes during molecular size chromatography with 1 mol/L acetic acid. They eluted at least partially in the expected fractions with 1 mol/L sodium chloride but further attempts at purification were unsuccessful due to progressive degradation. It is suggested that ionic bonds between IGFBP-2 and other components, such as proteoglycans, provide protection from proteolysis in a similar way as shown for IGFBP-1 and alpha2-macroglobulin.

Some metabolic and endocrine consequences of portacaval shunt were examined in rats eight weeks after the operation. Plasma levels of insulin, glucagon somatostatin, such as pancreatic content of insulin, glucagon, and somatostatin were determined by radioimmunoassay. Numerous biochemical parameters, such as the concentration of serum ammonia, transaminase (AST and ALT), urea bilirubin, total plasma protein and plasma albumin levels were determined by standard biochemical tests. Normal plasma levels of insulin and somatostatin hyperglucagonaemia were observed in rats with portacaval shunt. After portacaval shunt there was a highly significant increase (p

Alterations of insulin-like growth factors (IGF-I and -II) and their binding proteins (IGFBP) in patients infected with Helicobacter pylori or Francisella tularensis are reported in this paper. Infections were diagnosed immunochemically, by determination of specific antibodies to each bacterial species. It was shown that IGF-I, IGF-II and IGFBP-3 concentrations were lower in patients with bacterial infections, while IGFBP-2 concentration increased in comparison with healthy adults. Although the effect was more pronounced in the case of H. pylori infection, statistically significant reductions of IGF-I and IGF-II were found in both groups of patients. For IGF-I p < 0.0001 and for IGF-II p = 0.037 in patients with H. pylori, while p = 0.017 and p = 0.032 in patients with F. tularensis. Alterations of the IGF system can be regarded as a combined effect of bacterial infection on immuno, gastrointestinal hepatobiliary and nutritional axes in the organism.