Cholesterol and phospholipids in human seminal plasma before and after vasectomy

38 men who had undergone vasectomy for fertility regulation had 3 semen samples taken before and 2 and 6 months after the operation in order to determine the concentration of cholesterol and phospholipids in the seminal plasma for the evaluation of any possible changes in the physiology of genital glands. Prior to vasectomy there were 130 +or- 50 million of spermatozoa/ml of ejaculate with a 75% +or- 11% motility in a sample of 35 men. There was no statistically significant change in cholesterol content before and 2 and 6 months after vasectomy nor was there a significant difference between free cholesterol and esterified cholesterol. This indicated good correspondence in the content of glandular secretions of the male genital tract mainly the prostate and the seminal vesicles. On the other hand the concentration of phospholipids diminished 2 and 6 months after vasectomy from 230 +or- 90 mcg moles/in 21 patients to 100 +or- and 100 +or- 20 mcg moles/1 in 15 patients respectively. There was no significant difference in the average volume of seminal plasma 2 and 6 months after vasectomy. The decrease of the phospholipid content could be attributed to the inhibition of the biosynthesis of phospholipids owing to the hypertrophy of the epididymis or the absence of phospholipid secretion originating from the testicular fluid. Not all alterations in genital glands are apparent immediately therefore time is an important parameter in the evaluation of the response of the organism to vasectomy.