Changes in pituitary-adrenal function under extreme cold in DHA-treated persistent estrous rats

Area of Science:

• Endocrinology
• Neuroendocrinology
• Reproductive Biology

Background:

• Dehydroepiandrosterone (DHA) is a neurosteroid hormone with significant roles in reproductive and adrenal functions.
• Neonatal exposure to hormones can induce long-lasting changes in endocrine systems.
• The pituitary-adrenal axis is a critical stress response system influenced by gonadal hormones.

Purpose of the Study:

• To investigate the effects of neonatal dehydroepiandrosterone (DHA) administration on the pituitary-adrenal axis response to cold stress in rats.
• To compare the plasma corticosterone levels and 14C-l-acetate incorporation into adrenal steroids in DHA-treated and control rats.

Main Methods:

• Rats were treated neonatally with dehydroepiandrosterone (DHA) or a vehicle control.
• Adult rats were exposed to cold stress (-5°C) for 12 hours.
• Plasma corticosterone levels were measured.
• Incorporation of 14C-l-acetate into corticosterone and cortisol was quantified.

Main Results:

• Cold exposure stimulated 14C-l-acetate incorporation into corticosterone and cortisol in both groups.
• DHA-treated rats exhibited significantly lower rates of increase in plasma corticosterone and 14C-incorporation compared to controls.
• Stress-induced pituitary-adrenal activity in DHA-treated rats displayed masculine patterns.
• Plasma corticosterone levels were higher in DHA-treated rats than in controls, despite a blunted response to acute stress.

Conclusions:

• Neonatal DHA administration alters the development and function of the pituitary-adrenal axis.
• DHA exposure appears to induce a persistent, potentially masculinized, modification of stress responsiveness.
• These findings suggest that early-life hormonal milieu can permanently impact neuroendocrine stress regulation.