Effect of insulin on glucose oxidation and amino isobutyric acid transport and binding of insulin in chicken thymocytes |
| |
Authors: | Jean Simon |
| |
Affiliation: | Station de Recherches Avicoles (Institut National de la Recherche Agronomique), Centre de Recherches de Tours, 37380 Nouzilly France |
| |
Abstract: | In chicken thymocytes isolated from 15–40 day-old chickens, after a 2 h incubation at 37°C, insulin stimulated amino isobutyric acid uptake (maximal response: 40–50% of increase at 1 μg insulin/ml and half maximal response at 60 ng/ml) by specifically stimulating the influx without altering the efflux. Insulin also stimulated glucose oxidation (maximal response: 11% of increase at 1 μg insulin/ml). Binding of 125I-labelled chicken insulin to thymocytes was rapid and higher at 15°C than at 37°C. At steady state, (90 min at 15°C), chicken, porcine and goose insulins were equipotent in inhibiting the binding of 125I-labelled chicken insulin. Maximal binding capacity was estimated at 1250 pg insulin/108 cells, i.e., 1250 binding sites/cell with an apparent dissociation constant of 200 ng insulin/ml at 15°C. Degradation of 125I-labelled chicken insulin in the incubation medium was negligible at 15°C but very noticeable at 37°C. Therefore, the low level of insulin binding at 15°C reflects a true scarcity of insulin receptors in chicken thymocytes as compared to rat thymocytes. |
| |
Keywords: | Glucose oxidation Amino isobutyric acid uptake Insulin (Chicken thymocyte) |
本文献已被 ScienceDirect 等数据库收录! |
|