THYROID-GLAND AND EPIDIDYMAL SPERM MOTILITY IN RATS

The purpose of this research was to investigate the effect of hypofunc tion of the thyroid gland, caused by radioactive suppression of the gl and, on the pattern of spermatozoa motility in different segments of t he rat epididymis. Thyroidectomy was obtained by i.p. infection of 270 mu Ci of I-131. After about 30 days, the animal reached hypothyroidis m as determined by serum level of T-4. When the motility pattern of th e sperm obtained from the epididymis of normal rats was compared to th at of hypothyroid animals, a drop in the parameter of path velocity (V AP), progressive velocity (VSL), and track speed (VCL) were detected. Hypofunction was associated with decreasing sperm motility in the epid idiymis. In thyroidectomized rats injected with T-4, no sperm motility changes were observed.