Seasonal changes in the chemical composition of red deer ( Cervus elaphus) semen

Abstract

During reproductive quiescence, apart from a rapid decrease in total protein content, there was a 2–3 fold decrease in the activity of certain enzymes (glutamic-oxaloacetic transaminase (GOT), alkaline phosphatase, acrosin inhibitors) in the seminal plasma of red deer stags. The activity of the enzymes of the spermatozoa, hyaluronidase and acrosin, increased in the seminal plasma, probably due either to ageing of the spermatozoa, accumulated in the epididymis, or to changes in the permeability of cell membranes. These phenomena were accompanied by an increased concentration of albumins originating in blood, and by a noticeable disappearance of globulin fractions. This would point to a change in the permeability of the tissue barriers in the deer stag reproductive system, and to a decreased rate of protein synthesis in particular sections of this system, especially in the epididymis, during reproductive quiescence.