Hyperprolactinemia does not influence hypothalamic-pituitary-adrenocortical function during hypoglycemia in women

Area of Science:

• Endocrinology
• Neuroendocrinology
• Reproductive Endocrinology

Background:

• Rheumatic disorders are associated with elevated prolactin and hypocortisolemia.
• Hyperprolactinemia's potential inhibitory effect on the hypothalamic-pituitary-adrenocortical (HPA) axis requires investigation.

Purpose of the Study:

• To assess the impact of hyperprolactinemia on HPA axis function and sympathoadrenal activity.
• To determine if elevated prolactin levels inhibit cortisol and ACTH responses to hypoglycemia.

Main Methods:

• Ten healthy female volunteers received domperidone (to induce hyperprolactinemia) or placebo.
• Insulin-induced hypoglycemia was used to stimulate the HPA axis and sympathoadrenal system.
• Plasma levels of prolactin, ACTH, cortisol, epinephrine, and norepinephrine were measured.

Main Results:

• Domperidone significantly increased prolactin levels but did not alter basal ACTH, cortisol, or catecholamine levels.
• Both domperidone and placebo groups showed similar significant increases in ACTH, cortisol, and epinephrine in response to hypoglycemia.
• Norepinephrine response to hypoglycemia was observed but was not influenced by domperidone.

Conclusions:

• Pharmacologically induced hyperprolactinemia does not significantly alter HPA axis function in healthy young women.
• Elevated prolactin levels do not appear to inhibit sympathoadrenal activity during hypoglycemia.
• These findings suggest prolactin does not play a significant inhibitory role in the human stress response.