The influence of bicuculline methiodide (BMI), a gamma‐aminobutyric acid (GABA) receptor antagonist, on central nervous system regulation of blood glucose homeostasis was studied in fed rats. Injection of BMI (1–10 nmol) into the third ventricle was found to produce hepatic venous hyperglycemia in a dose‐dependent manner. This change was associated with increased secretion of epinephrine and glucagon. The role of epinephrine in hyperglycemia was then studied in bilaterally adrenalectomized (ADX) rats injected with BMI. Plasma glucose concentration was found to increase in ADX rats although the level was approximately half that for intact rats and significantly higher than for controls. The increase in epinephrine and glucagon secretion seen in intact rats, but not in ADX rats, suggests BMI‐induced epinephrine release is responsible for the glucagon secretion. Three possible mechanisms are suggested to account for the rise in plasma glucose in the hepatic vein after injection of BMI: 1) that epinephrine is secreted by the adrenal medulla, 2) that epinephrine secretion stimulates glucagon secretion or 3) that there may be some direct innervation of the liver in rats.
|Number of pages||4|
|Journal||Journal of Neuroendocrinology|
|Publication status||Published - 1994 Jan 1|
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience