Decreased inflammatory responsiveness of hypophysectomized rats to heat is reversed by a corticotropin-releasing factor (CRF) antagonist.
Hypophysectomy, but not adrenalectomy, decreased (relative to sham-operated controls) the swelling and Evans blue dye extravasation responses of the anesthetized rat's pawskin to thermal injury. alpha-Helical CRF (9-41), a synthetic competitive antagonist of corticotropin-releasing factor (CRF) on isolated pituitary cells, did not affect in sham-operated rats the swelling response after immersion of the paw in 58 degrees C water for 30 s. Swelling was measured over a 1 h period using the fluid displacement method for quantifying paw volume. But, when alpha-helical CRF (9-41) was injected 92 micrograms/kg i.v. 10 min before or immediately after heat exposure, it both attenuated and reversed the insensitive state produced by hypophysectomy: that is, the swelling response reappeared. Under the same test conditions, naloxone hydrochloride, an opioid antagonist, was ineffective. The results suggest that hypophysectomy may induce a condition whereby endogenous CRF or CRF-like peptides may act as an anti-inflammatory agent.
Wei
E T
ET
School of Public Health, University of California, Berkeley 94720.
Wong
J C
JC
Kiang
J G
JG
D000315:Adrenalectomy; D000818:Animals; D002056:Burns / Q000503:physiopathology*; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D004487:Edema / Q000517:prevention & control*; D018409:Foot Injuries; D005552:Forelimb / Q000293:injuries; D007016:Hypophysectomy; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D010446:Peptide Fragments; D003346:Corticotropin-Releasing Hormone; C045089:corticotropin releasing hormone (9-41)