Effect of interleukin-1 beta on plasma ACTH, beta-endorphin, and corticosterone levels in infant and prepubertal rats.
IL-1 beta is known to enhance ACTH release from the anterior pituitary in the adult rat, mainly by simulating the hypothalamic ACTH-releasing hormone (CRH) release, but it seems to have a direct effect on the pituitary and on the adrenal hormone secretion, too. The effect of IL-1 beta on the beta-endorphin (beta E) secretion from the intermediate lobe is less well studied. There is very little information on the effect of IL-1 beta on the hypothalamic-pituitary-adrenal axis (HPAA) in the postnatal rat, which is a special period, because the reactivity of the HPAA is blunted. The effect of IL-1 beta in this period seemed to be of special interest, because neither the immune nor the endocrine system is fully developed. In the present study we tested the 30- and 120-min effect of intraperitoneally administered 0.5 and 100 ng/g body weight IL-1 beta on the plasma immunoreactive (ir) ACTH, beta E, and corticosterone (CS) levels in the 10-d-old (infant) and 30-d-old (prepubertal) rat. Generally, the ir-ACTH, ir-beta E, and ir-CS levels were significantly higher in prepubertal than in infant rats. Hormone levels were more enhanced by the higher dose of IL-1 beta, and changes were more pronounced at 120 min than at 30 min. The relative increase of ir-ACTH and ir-beta E was smaller in the infant than in the prepubertal rat. In contrast, the relative increase of ir-CS was more pronounced in the infant rat.(ABSTRACT TRUNCATED AT 250 WORDS)
Barna
I
I
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
Acs
Z
Z
Bugovics
G
G
Koenig
J I
JI
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D000831:Animals, Newborn; D003345:Corticosterone / Q000097:blood*; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D007375:Interleukin-1 / Q000494:pharmacology*; D008297:Male; D010913:Pituitary-Adrenal System / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012741:Sexual Maturation / Q000502:physiology*; D001615:beta-Endorphin / Q000097:blood*
D007375:Interleukin-1; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone