Release of proinflammatory cytokines related to luteolysis and the periparturient acute phase response in prostaglandin-induced parturition in cows.

摘要

A physiological reaction to tissue damage, known as the acute phase response, has been reported previously in cows at parturition. To monitor the changes that occur during the acute phase response, 5 cows in late pregnancy (256-262 days) were implanted with vascular catheters in the maternal aorta and uterine vein. On day 275, PG was given to induce luteolysis. Plasma concentrations of the proinflammatory cytokines, tumour necrosis factor-alpha, interleukin-1 and interleukin-6, as well as progesterone, PGF metabolite and serum amyloid A (SAA) were measured every 4 h between PG injection and expulsion of the calf. In the arterial plasma, progesterone levels declined to baseline values within 10 h of PG treatment, indicating complete luteolysis. Contrary to expectation, the uterine vein samples showed lower proinflammatory cytokine concentrations than maternal aorta samples. A classical acute phase response, as assessed by SAA, was observed during the expulsive stage, but not during luteolysis.