Effects of interleukin-1-beta, interleukin-6 and tumor necrosis factor-alpha, alone or in association with hexarelin or galanin, on growth hormone gene expression and growth hormone release from pig pituitary cells.
OBJECTIVE
We studied the effects of IL-1beta, IL-6 and TNF-alpha on GH gene expression and secretion with or without galanin and hexarelin.


METHODS
Pituitary cells from adult pigs were treated with IL-1beta, IL-6 or TNF-alpha (1, 10 and 100 ng/ml), alone or in association with galanin or hexarelin (10(-8) M): GH mRNA was measured by RT-PCR and GH secretion by ELISA.


RESULTS
IL-1beta (1, 10 and 100 ng/ml) and IL-6 (1 and 10 ng/ml) significantly (p < 0.05) enhanced GH output. IL-1beta and TNF-alpha (1 and 10 ng/ml) reduced (p < 0.05) the galanin-induced GH secretion and IL-6 (10 ng/ml) potentiated the effect of both GH releasers (p < 0.05). GH gene expression was increased only by IL-6 at the concentrations of 1 and 10 ng/ml, either alone or in association with both galanin and hexarelin.


CONCLUSIONS
We hypothesize that cytokines may play a paracrine/autocrine role in GH regulation in the pituitary independently from the intracellular pathways of the GH secretagogues.
D000818:Animals; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D005260:Female; D019004:Galanin / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D013006:Growth Hormone / Q000235:genetics* / Q000378:metabolism*; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D013552:Swine; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D009842:Oligopeptides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C086184:hexarelin; D019004:Galanin; D013006:Growth Hormone