Production of insulin-like growth factor I and its binding protein in rat hepatocytes cultured from diabetic and insulin-treated diabetic rats.
Production of insulin-like growth factor I and its binding protein in rat hepatocytes cultured from diabetic and insulin-treated diabetic rats.
复制标题
糖尿病大鼠和经胰岛素治疗的糖尿病大鼠培养的大鼠肝细胞中胰岛素样生长因子 I 及其结合蛋白的产生。
作者:
C. Scott;R. Baxter
This study examines the effect of experimental diabetes on the release of rat insulin-like growth factor I (rIGF-I) and its binding protein (IGF-BP) by adult rat hepatocytes in primary culture. Rats treated with streptozotocin (75 mg/kg) had decreased serum rIGF-I values of 0.37 +/- 0.04 U/ml compared to 1.06 +/- 0.04 in age-matched untreated rats (1 U = 770 ng human IGF-I). Concomitant decreases in hepatocyte production rates for rIGF-I (15% of the rate in cells from normal rats) and IGF-BP (30% of normal) were also observed for hepatocytes isolated from diabetic rats. Insulin replacement therapy (1.2 U/day) for 3-4 days normalized serum rIGF-I levels (0.92 +/- 0.07 U/ml) and increased rIGF-I production by isolated hepatocytes to 67% the rate of normal cells and IGF-BP production to 70% normal. Treatment of streptozotocin-treated rats with rGH (150 micrograms/day) in vivo for 7 days failed to increase serum rIGF-I levels or hepatocyte production of rIGF-I. Insulin in vitro (3 X 10(-7) M) increased rIGF-I release by hepatocytes from nondiabetic rats, but had no effect on cells from diabetic animals, suggesting that factors other than insulin are required to maintain rIGF-I synthesis in diabetes. Serum rIGF-I levels showed a strong correlation with hepatocyte rIGF-I production in the animals used in this study. However, calculation of circulating rIGF-I half-life based on these values showed a 2-fold higher half-life in diabetic rats (7.91 +/- 1.58 h) and rGH-treated diabetic rats (7.52 +/- 1.25 h) than in nondiabetic (2.99 +/- 0.35 h) and insulin-treated diabetic animals (3.85 +/- 0.36 h). This suggests that the rate of clearance of circulating rIGF-I may be slower in diabetic animals.
DOI:
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发表时间:
1986-01
期刊:
The Journal of biological chemistry
影响因子:
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作者:
T. B. Miller;A. Garnache;J. Cruz;R. McPherson;C. Wolleben
通讯作者:
T. B. Miller;A. Garnache;J. Cruz;R. McPherson;C. Wolleben
DOI:
10.1073/pnas.81.3.935
发表时间:
1984-01-01
期刊:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子:
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作者:
DERCOLE, AJ;STILES, AD;UNDERWOOD, LE
通讯作者:
UNDERWOOD, LE