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Melittin-evoked increase in plasma corticosterone levels.
1Department of Anatomy, Oral Roberts University School of Medicine, Tulsa, Oklahoma 74171.
Life Sciences
|January 1, 1988
Summary
Melittin administration significantly increases corticosterone levels in female rats, impacting pituitary-adrenal function. This effect is dose-dependent and sensitive to dexamethasone suppression, indicating feedback regulation.
Area of Science:
- Endocrinology
- Neuroscience
- Pharmacology
Background:
- The pituitary-adrenal (PA) axis regulates the stress response.
- Melittin, a peptide from bee venom, has known physiological effects.
- Its impact on non-stress PA function requires systematic evaluation.
Purpose of the Study:
- To investigate the effect of melittin on basal pituitary-adrenal function in adult female rats.
- To determine the dose-response and duration of melittin's effect on corticosterone levels.
- To assess the feedback sensitivity of melittin-induced adrenocortical activity.
Main Methods:
- Adult female rats received intraperitoneal injections of melittin (0.5 mg/kg) or saline.
- Plasma corticosterone levels were measured at various time points post-injection.
- Dexamethasone suppression tests were conducted to evaluate feedback mechanisms.
Main Results:
- Melittin administration led to significantly elevated plasma corticosterone levels at 4 and 48 hours post-injection.
- The melittin-evoked corticosterone response persisted for 3 days but diminished by day 6.
- A double injection protocol extended the elevated corticosterone response to 8 days.
- Melittin-induced increases were observed only in the morning and were suppressed by dexamethasone.
Conclusions:
- A 0.5 mg/kg dose of melittin significantly enhances adrenocortical activity in female rats.
- The melittin-induced increase in corticosterone is time-dependent and exhibits feedback sensitivity.
- These findings elucidate melittin's role in modulating the pituitary-adrenal axis.