The objective of this study was to evaluate the effects of two sublethal doses (4 and 20 mg/kg live weight (LW); every other day) of gossypol on semen and hormonal characteristics of male rabbits. The experiment lasted 16 weeks and included two periods: a treatment period (first 8 weeks) where the animals were given the test materials, and a recovery period (second 8 weeks) where drugs were withdrawn. Results showed that LW and respiration rate (RR) decreased ( P , 0·05) among animals that received gossypol, while rectal temperature increased ( P , 0·05). Animals in gossypol treatment groups had decreased ( P , 0·05) blood plasma levels of tri-iodothyronine (T 3 ) and testosterone. This was accompanied by reductions ( P , 0·05) in sperm concentration, total sperm output, percentage incidence of forward motility, total functional sperm fraction and semen initial fructose concentration. Gossypol however increased ( P , 0·05) reaction time (i.e. decreased libido), percentages of dead sperm and abnormal sperm (AbSp) and altered acrosomes. Estimated weights of testes and semen ejaculate volume increased ( P , 0·05) possibly due to increased water retention. Values of LW, RR, AbSp, and blood plasma T 3 and testosterone returned to control levels after withdrawal of gossypol, while the effect of this drug on other parameters continued during the recovery period.

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This study was done to evaluate the effects of two sublethal doses of gossypol (4 and 20 mg/kg of BW, every other day) on some amino and fatty acid concentrations in male rabbit seminal plasma. Rabbits were chosen as an experimental animal owing to the fact that they are excellent model for reproductive toxicological effects. The experiment lasted 16 weeks and included two periods: a treatment period (first 8 weeks) where the animals were given the tested product, and a recovery period (second 8 weeks) where all drugs were withdrawn. Results showed that total amino acids (TAA), total essential amino acids (EAA), total non-essential amino acids (non-EAA) and EAA/non-EAA ratio were decreased in a dose-dependent manner during gossypol treatment. The deleterious effect on TAA concentrations was mainly due to the reduction in total EAA. However, these concentrations regained their normal values after gossypol cessation. Basic, acidic, neutral amino acids and basic/acidic amino acids ratio decreased in a dose-dependent manner by gossypol treatment. Additionally, gossypol administration caused decreases in total unsaturated fatty acids (USFA) and increases in total saturated fatty acids (SFA) and the SFA/USFA ratio in a dose-dependent manner. During the recovery period, total SFA and USFA showed significant reduction and significant increase, respectively, after gossypol withdrawal. In conclusion, gossypol administration affected rabbit seminal plasma concentrations of amino and fatty acids in a dose-dependant manner. Gossypol reduced TAA, total EAA and total non-EAA. Additionally, gossypol caused decreases in total USFA and increases in total SFA. These deleterious effects were associated with poor-quality semen observed in our previous studies.

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