THE EFFECT OF NICOTINE ON IN-VITRO SPERM MOTION CHARACTERISTICS

Purpose and study plan: Men who are habitual smokers tend to have poor semen quality. We studied the effect of nicotine on sperm motility in vitro, Spermatozoa from 13 normal fertile nonsmoking donors, washed f ree of seminal plasma, were treated with medium alone (control); and, 10 mM, 5 mM, 1 mM and 0.1 mM nicotine (concentrations estimated to app roximate residual concentrations of nicotine in the testes of heavy sm okers). Computerized sperm motion analysis (CASA) was done at 2, 4, 6 and 24 h after incubation. Results: Sperm motility, beat/cross frequen cy, linearity and maximum anterior, lateral head displacement (ALH max .) were significantly decreased across nominal dosages (P < 0.001 by r epeated measures analysis of variance). Of the concentrations tested, 0.1 mM had no effect; 1 mM significantly decreased sperm motility (P = 0.003) and linearity (P = 0.02); 5 mM decreased the beat frequency (P = 0.001) and linearity (0.02); and 10 mM markedly decreased motility (P = 0.0001), beat frequency (P = 0.0002), linearity (P = 0.02) and AL H max. (P = 0.02). The interactions between dose and time were insigni ficant. Conclusion: Nicotine at concentrations of greater than or equa l to 1 mM significantly decreased sperm motion characteristics after d ifferent periods of incubation, whereas 0.1 mM concentration had the l east effect.