Balancing shiftwork and life outside work: Do 12-h shifts make a difference?

Abstract

Amounts of ߁-activin, ߃-activin, activin receptor subunits ActRIIA and ActRIIB mRNA, and ߁- and ߃-activin subunit protein immunoreactivity were investigated in male Lewis rats, either untreated or after 5 or 10 weeks of CCl4 treatment to induce cirrhosis. Apoptosis was assessed histologically and with an in situ cell death detection kit (TUNEL). Reverse transcription and polymerase chain reaction were used to evaluate mRNA levels. Activin ߁- and ߃-subunit immunoreactivity was studied by immunohistochemistry using specific monoclonal antibodies. Hepatocellular apoptosis (P<0.001), increased ߁- and ߃-activin mRNAs (three- to fourfold; P<0.01) and increased ߁- and ߃-activin tissue immunoreactivity were evident, whereas ActRIIA mRNA concentrations fell (30%; P<0.01) after 5 weeks of CCl4 treatment. The mRNA concentrations at 10 weeks were not significantly different from controls, despite extensive hepatic nodule formation. We conclude that the increased activin subunit expression is associated with apoptosis, rather than hepatic fibrosis and nodule formation.