Related Experiment Videos
ACTH immunoactivity in normal rat tissues: modulation by hypophysectomy and adrenalectomy
1Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132.
Endocrine Research
|January 1, 1992
Summary
Adrenalectomy significantly increases adrenocorticotropin (ACTH)-like immunoactivity in rat kidneys, suggesting a blood-derived source. Other peripheral tissues showed no significant changes after pituitary-adrenal axis perturbation.
Area of Science:
- Endocrinology
- Physiology
- Molecular Biology
Background:
- The pituitary-adrenal axis regulates stress response via hormones like ACTH.
- Understanding ACTH distribution in peripheral tissues is crucial for comprehending its systemic effects.
- Perturbations in this axis can lead to altered hormone levels and tissue-specific responses.
Purpose of the Study:
- To investigate the impact of hypophysectomy and adrenalectomy on ACTH-like immunoactivity in rat peripheral tissues.
- To determine if ACTH or related peptides accumulate in specific organs following disruption of the pituitary-adrenal axis.
- To identify potential tissue-specific roles or reservoirs of ACTH-like substances.
Main Methods:
- Adult male rats underwent hypophysectomy or adrenalectomy, with tissue collection at 1, 7, 14, and 28 days post-surgery.
- ACTH-like immunoactivity was measured using a polyclonal antibody (West antibody) in glacial acetic acid extracts.
- Tissues analyzed included liver, colon, heart, small intestine, and kidney.
- Gel filtration was employed to characterize the molecular weight of the immunoactivity.
Main Results:
- ACTH-like immunoactivity in liver, colon, heart, and small intestine remained unchanged after both hypophysectomy and adrenalectomy.
- Kidney ACTH-like immunoactivity was unaffected by hypophysectomy.
- Adrenalectomy led to a significant, progressive four-fold increase in kidney ACTH-like immunoactivity starting at 7 days post-surgery.
- Gel filtration indicated the increased kidney immunoactivity primarily consisted of the 4.5 kD form, consistent with serum ACTH.
Conclusions:
- The pituitary-adrenal axis plays a critical role in regulating ACTH levels in peripheral tissues.
- Kidneys exhibit a unique response to adrenalectomy, with increased ACTH-like immunoactivity likely originating from the bloodstream.
- These findings suggest that peripheral tissues, particularly the kidney, may be influenced by circulating ACTH in ways not previously recognized, especially under conditions of adrenal insufficiency.