Inhibitory effects of proopiomelanocortin on cortical and medullary activity in the calf adrenal.

Abstract

The effects of the infusion of ACTH1-24 and proopiomelanocortin on the denervated adrenal gland have been investigated in conscious 3-6 weeks-old calves by means of the adrenal-clamp technique. To prevent variation in the release of endogenous ACTH the pituitary stalk was cauterized during preparatory surgery. ACTH1-24 (5 ng/min per kg, i.v.) increased the output of cortisol from the adrenal by about 500 ng/min per kg body weight and this effect was rapidly reduced by simultaneous infusion of ovine proopiomelanocortin at 5 ng/min per kg. Release of met5-enkephalin and leu-enkephalin from the adrenal was reduced by ACTH1-24 (P less than 0.05) and this effect was enhanced significantly by additional infusion of proopiomelanocortin (P less than 0.02). However met5-enkephalin represented less than one-third of the met-enkephalin containing peptide released and the output of this pool was unaffected by infusion of ACTH. Proopiomelanocortin had no effect on met5-enkephalin production nor that of the total pool of met5-enkephalin containing peptides. It is concluded that ACTH reduced the quantity of pro-enkephalin processed to met5-enkephalin.

• Authors: C T Jones, A V Edwards, D Tindell
• Journal: Journal of developmental physiology (J Dev Physiol) Vol. 17 Issue 2 Pg. 69-73 (Feb 1992) ISSN: 0141-9846 [Print] England
• PMID: 1323590 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Enkephalins
• Protein Precursors
• proenkephalin
• Cosyntropin
• Enkephalin, Methionine
• Enkephalin, Leucine
• Pro-Opiomelanocortin
• Adrenocorticotropic Hormone
• Hydrocortisone

Topics

• Adrenal Cortex (drug effects, metabolism)
• Adrenal Medulla (drug effects, metabolism)
• Adrenocorticotropic Hormone (blood)
• Animals
• Cattle
• Cosyntropin (pharmacology)
• Enkephalin, Leucine (blood, metabolism)
• Enkephalin, Methionine (blood, metabolism)
• Enkephalins (metabolism)
• Hydrocortisone (blood, metabolism)
• Hypophysectomy
• Pro-Opiomelanocortin (pharmacology)
• Protein Precursors (metabolism)