The effect of freezing and storage on seminal immunoreactive prolactin

Thirteen subjects were studied to compare changes in seminal immunoreactive prolactin produced by storage and freezing of semen and seminal plasma separated within 2 hours of ejaculation. Seminal prolactin was significantly higher in semen than in seminal plasma (paired t test, t = 3.29, p less than 0.005). The difference in prolactin between the two values correlated with sperm count (linear regression analysis, r = 0.65, p less than 0.02). This study suggested that variations in reported correlations between sperm count and seminal prolactin might be explained in part by the time interval of semen collection, centrifugation, and/or freezing.