Relationship between platelet-activating factor concentration in rhesus monkey (Macaca mulatta) spermatozoa and sperm motility

Platelet‐activating factor (PAF) is a potent signaling phospholipid that has been implicated in a number of biological activities. PAF concentration in primate spermatozoa has a positive correlation with fertility. While PAF is present in rhesus spermatozoa, there are no relational reports on its concentration and the cell’s motility. The study objective was to determine if PAF concentration in rhesus spermatozoa was correlated with motility indices (percent motility and forward progression). Semen was collected from sexually mature males and cell counts, and percent motilities and forward progressions were recorded prior to PAF measurement by radioimmunoassay. Spermatozoa‐derived PAF concentration ranged from a low of 0.9 picomoles/106 cells to a high of 13.0 picomoles/106 cells. The overall mean (±SEM) PAF concentration was 4.6 (±1.6) picomoles/106 spermatozoa. Regression analysis revealed a positive and significant relationship between PAF concentration in the spermatozoa and percent motility (R2 = 0.914; P < 0.01) as well as forward progression (R2 = 0.849; P < 0.05). A receiver‐operator characteristic curve and the calculation of the probability that a positive forward progression will be predicted indicated a cutoff limit of 1.5 picomoles/106 cells for PAF concentration in rhesus sperm. Rhesus monkey spermatozoa motility was significantly greater (P < 0.01) in the high‐PAF (≥2 picomoles/106 cells) group (31.0 ± 7.6) than in the low‐PAF (