Related Experiment Videos
Insulin secretion during acid-base alterations.
The American Journal of Physiology
|April 1, 1978
Summary
Extracellular pH significantly impacts insulin secretion. Alkalosis (high pH) reduced insulin release, while acidosis (low pH) had variable effects depending on the stimulus, suggesting interference with beta cell emiocytosis.
Area of Science:
- Endocrinology
- Physiology
- Cell Biology
Background:
- Extracellular acid-base balance is crucial for physiological functions.
- Insulin secretion by pancreatic beta cells is a tightly regulated process.
- Understanding how pH affects insulin release is vital for metabolic health.
Purpose of the Study:
- To investigate the effects of metabolic acidosis and alkalosis on insulin secretion.
- To determine how different stimuli interact with pH-mediated changes in insulin release.
- To elucidate the potential mechanisms underlying pH-induced alterations in beta cell function.
Main Methods:
- In vitro perfused rat pancreases were utilized.
- Pancreases were challenged with glucose, arginine, and tolbutamide under varying pH conditions (7.0, 7.4, 7.8).
- Insulin secretion was measured in response to these stimuli at different extracellular pH levels.
Main Results:
- Alkalosis (pH 7.8) consistently reduced insulin secretion compared to the control (pH 7.4) regardless of the stimulus.
- Acidosis (pH 7.0) enhanced insulin secretion stimulated by glucose and glucose plus arginine.
- Acidosis (pH 7.0) reduced insulin secretion with glucose plus tolbutamide and affected only the first phase of secretion with high glucose.
Conclusions:
- Extracellular pH significantly modulates insulin secretion from pancreatic beta cells.
- High extracellular pH (alkalosis) generally impairs insulin release.
- Low extracellular pH (acidosis) has differential effects on insulin secretion depending on the secretagogue, potentially by interfering with beta cell emiocytosis.