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Insulin affects ionic composition of rainbow trout erythrocytes
1Department of Biological Sciences, Brock University, St. Catharines, Canada.
Regulatory Peptides
|August 1, 1988
Summary
Rainbow trout red blood cells respond to insulin, showing increased potassium and water content. This suggests that fish erythrocytes possess insulin receptors, similar to mammals.
Area of Science:
- Comparative physiology
- Endocrinology
- Cell biology
Background:
- Mammalian erythrocytes are anucleate and exhibit insulin sensitivity.
- Understanding erythrocyte function in non-mammalian vertebrates provides insights into evolutionary adaptations.
Purpose of the Study:
- To investigate the insulin sensitivity of anucleate red blood cells in rainbow trout (Salmo gairdneri).
- To determine if rainbow trout erythrocytes possess insulin receptors.
Main Methods:
- Erythrocytes were cultured in vitro with varying concentrations of insulin (20, 200, 2000 microU/ml) for 2 and 6 hours.
- Ionic composition (potassium, sodium, magnesium, chloride) and water content were measured and compared to control cells cultured in insulin-free medium.
Main Results:
- Insulin exposure led to dose-dependent increases in intracellular potassium and water content.
- Conversely, sodium, magnesium, and chloride levels decreased in a dose-dependent manner with insulin treatment.
- These changes were observed at both 2 and 6-hour time points.
Conclusions:
- Rainbow trout anucleate erythrocytes demonstrate insulin sensitivity.
- The observed alterations in ionic and water content suggest the presence of insulin receptors on the erythrocyte membrane.
- This finding highlights a conserved mechanism of insulin action across vertebrate erythrocyte types.
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