Effect of two phosphodiesterase inhibitors, cyclic adenosine 3':5'-monophosphate, and a beta-blocking agent on human sperm motility.

Mann-fructose fluid (MF), and MF plus caffeine, MF plus pentoxifylline, MF (dibutyryl cAMP), MF plus propranolol, and MF plus propranolol plus dibutyryl cAMP were individually added to aliquots of semen samples obtained from 18 normal men. These drugs were added to a final concentration of 0.6 mM. One aliquot with no addition served as control. Samples were incubated at 37 degrees C and observed by light microscopy at 30 minutes and at 1,2, and 4 hours after obtained the material. At each observation time, semen quality was evaluated by determinating the percentages of forwardly progresssive spermatozoa, slowly progressive spermatozoa, "in situ" motile spermatozoa, live and nonmotile spermatozoa, and dead spermatozoa. Mann-fructose fluid resulted in a decrease in motility and the duration of activity of spermatozoa, Caffeine seemed to neutralize the deleterus effect on the buffer, whereas pentoxifylline and cAMP seemed to increase the duration of activity of spermatozoa. Propranolol resulted in a dramatic decrease in motility, an effect that could not be neutralized by the simultaneous addition of cAMP.