Rat activin-βE mRNA expression during development and in acute and chronic liver injury

Activin-betaE mRNA expression was investigated in male and female rats using gel-based and quantitative RT-PCR, in fetal and post-natal liver during development and in a variety of tissues from 200 gm adult animals. Activin-betaE expression was also assessed in rat liver after partial hepatectomy, and after repeated toxic insult. Male Sprague Dawley rats were subjected to partial hepatectomy or sham operations. Samples were collected from the caudate liver lobe during regeneration, from 12 to 240 hr after surgery. Three groups of 5 male rats were treated with CCl(4) for 0 (control), 5 or 10 weeks, to induce liver fibrosis and cirrhosis. Activin-betaE mRNA was predominantly expressed in liver, with much lower amounts of mRNA observed in pituitary, adrenal gland and spleen, in both males and females. Low activin-betaE expression was observed in liver at fetal day 16, with higher levels seen between post-natal days 3 and 35 and a further increase noted by day 47, in both males and females. Liver activin-betaE mRNA concentrations did not change from control values 12-72 hr after PHx, but significantly increased over six fold, 168 hr post-hepatectomy, when liver mass was restored. Activin-betaE mRNA was up-regulated after 5 weeks of CCl(4) treatment, but not after 10 weeks. The changes in activin-betaE mRNA concentrations after liver insult did not always parallel those reported for the activin-betaC subunit, suggesting activin-betaE may have an independent role in liver under certain conditions.