![]() ![]() Diabetes mellitus was documented at 24 h by a rise in plasma glucose (vehicle-injected control, 133 +/- 4 diabetic, 482 +/- 22 mg/dl and a fall in plasma insulin (control, 53.1 +/- 5.7 diabetic, 35.6 +/- 4.0 microIU/ml. Glomerular angiotensin II receptors were measured by Scatchard analysis insulin, renin activity, angiotensin II, and aldosterone were measured by RIA. The time course and role of the renin-angiotensin-aldosterone system in the pathogenesis of the receptor abnormality were studied in male Sprague-Dawley rats made diabetic with streptozotocin (65 mg, iv). Glomerular angiotensin II receptors are reduced in number in early diabetes mellitus, which may contribute to hyperfiltration and glomerular injury. Reduced glomerular angiotensin II receptor density in diabetes mellitus in the rat: time course and mechanism We conclude that rat hepatocytes in primary culture contain specific IGF- II receptors and that both cell surface and intracellular receptors are regulated by cell density There was no evidence that IGF binding proteins, either secreted by hepatocytes or present in fetal calf serum, had any effect on the measurement of receptor concentration or affinity. The increase was not due simply to the exposure of receptors from the intracellular pool, as a density-related increase in receptors was also seen in cells permeabilized with digitonin. In hepatocytes cultured at low densities, the number of cell surface receptors increased markedly, from 10-20,000 receptors per cell at a culture density of 6 X 10(5) cells/well to 70-80,000 receptors per cell at 0.38 X 10(5) cells/well. Determined by Scatchard analysis and by polyacrylamide gel electrophoresis after affinity labeling, the higher binding was due solely to an increase in binding sites present on 220 kDa type II IGF receptors. IGF- II binding increased when cells were permeabilized with 0.01% digitonin, suggesting the presence of an intracellular receptor pool. Less than 1% cross-reactivity by IGF-I and no cross-reactivity by insulin were observed. In hepatocytes cultured at 5 X 10(5) cells per 3.8 cm2 plate IGF- II bound to specific, high affinity receptors (Ka = 4.4 +/- 0.5 X 10(9) l/mol). ![]() Insulin-like growth factor- II (IGF- II) receptors in primary cultures of adult rat hepatocytes were characterized and their regulation by cell density examined. International Nuclear Information System (INIS) Insulin-like growth factor- II receptors in cultured rat hepatocytes: regulation by cell density ![]()
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