[Passive immunization with an anti-oCRF41 immune serum inhibits the circadian increase of plasma ACTH in rats].
For 24 hrs. after i.v. injection of 1 ml of an undiluted immune serum raised against oCRF41, the diurnal surge of plasma ACTH dropped to a short-lived limited rise above baseline level. On the second day after injection, the ACTH level in treated rats rose to a subnormal level, although both plasma dilution of the immune serum and its binding capacity in the plasma remained unchanged throughout the experiment. Plasma corticosterone, on the contrary, displayed a normal circadian rhythm during the entire experiment. However, in animals given a second injection of 0.5 ml oCRF41 immune serum 32 hrs. after the first, both ACTH and corticosterone titers fell rapidly below their circadian minimal levels in controls. Concomitantly, the concentration of immune serum in the peripheral plasma, and its capacity to bind to oCRF, rose by 50%. The major role of CRF41 as a diurnal trigger of the circadian rhythm of ACTH is discussed, as well as the limits of passive immunization.
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000276:immunology / Q000502:physiology*; D007106:Immune Sera / Q000494:pharmacology; D007116:Immunization, Passive; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D007106:Immune Sera; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone
L'immunisation passive avec un immun-sérum anti-oCRF41 inhibe l'augmentation circadienne de l'ACTH plasmatique chez le rat.