The effect of zinc deficiency on prostaglandin synthesis in rat testes

The effect of zinc deficiency on prostaglandin synthesis in rat testes was determined by feeding three groups of rats egg white-based semipurified diets. One group (ZD) was fed a zinc-deficient diet and two control groups were pair-fed (PF) or fed ad libitum (AL) a zinc-sufficient diet. The concentration (nanograms/gram) of the prostacyclin metabolite, 6-keto-prostaglandin-F1 alpha (6-keto-PGF1 alpha), in the tunica homogenate was significantly lower in ZD than in PF and AL groups. However, there was no difference when 6-keto-PGF1 alpha concentration was expressed as nanograms/milligrams of tunica protein. Tunica PGE2 concentrations (nanograms/gram) were not significantly altered by zinc deficiency. Concentrations of prostaglandins (PGs) in testis parenchyma were slightly higher in ZD probably as a result of increased levels of the precursor, arachidonic acid (AA). There was a highly significant correlation between PGE2 and AA in parenchyma phospholipids. PG synthesis was much greater in the tunica than in the parenchyma and prostacyclin appeared to be the major PG synthesized in both the tunica and parenchyma. It was concluded that PG synthesis is altered in the testes of zinc-deficient rats probably due to changes in concentrations of protein in the tunica and AA levels in parenchyma lipids.