GH regulation by activin and follistatin in grass carp pituitary cells.

Abstract

<p>Effects of increasing doses of human activin A and B on (A) GH secretion and GH cell content, and (B) GH mRNA expression in carp pituitary cells. In parallel experiments, the effects of removing endogenous activin with increasing levels of human follistation on (C) GH secretion and GH cell content, and (D) GH mRNA expression were also examined. In these studies, the duration of drug treatment was fixed at 48 hr. After treatment, culture medium (for GH release) and cell lysate (for GH cell content) were harvested and subjected to Western blot with GH antiserum with parallel blotting of β actin expression as the internal control. In separate experiments, total RNA was also isolated for real-time PCR of GH mature mRNA. GH mRNA data presented (Mean ± SEM) are pooled results from four separate experiments (N = 4) and the groups denoted by different letters represent a significant different at P < 0.05 (ANOVA followed by Newman-Keuls test).</p