Prostaglandin Levels in Avian Blood and Reproductive Organs

Abstract

A radioimmunoassay with a sensitivity of 5 pg/assay tube was established to measure prostaglandins E, F, and A in avian plasma and tissues. Compared to plasma values when no egg is present in the uterus (shell gland), PGE but not PGF or PGA levels were significantly higher in hens in which an egg was present (P<0.001). However, in the various segments of the oviduct as well as in the lung, PGF levels were 2-8 times higher than PGE levels. In the plasma of laying Japanese quail hens, both PGE and PGF (but not PGA) levels were significantly higher than in birds that ceased to lay. Relatively high PGE concentrations were found in turkey hens during the day (855 pg/ml), and these increased significantly in the evening (1310 pg/ml). Prostaglandin levels in the plasma of roosters were generally lower than in hen plasma. Similarly, concentrations in the testes were considerably lower than those found in ovaries. It is suggested that, in the domestic hen, E prostaglandins are involved not only in promoting oviposition (as previously proposed) but also in mobilizing calcium from skeletal stores during the hours of intensive shell formation.