Mixing organophosphate (OP) and pyrethroid (PYR) insecticides becomes common in Egypt since
mid-1980s and result in an impairment of male reproductive function. The
present investigation was conducted to study certain criteria used to evaluate
the reproductive toxicity of treated male rats with the commercial preparation
of OP/PYR mixture, namely Runsave,
which  contains 30% chlorpyrifos (CPF) and 3% lambda-cyhalothrin (LTC) compared to its individual commercial
components of 48% E.C (CPF) and 5%
E.C (LTC). Adult male rats were
treated dermally with sublethal dose of each toxicant (6 rats each) on
alternate day for 8 weeks, then they were sacrificed except few rats that
treated with Runsave mixture. The relative testes weights, semen picture,
activities of plasma and brain cholinesterases as well as histopathological changes
in testes were determined. The remaining rats that treated with Runsave were
allowed to mate with untreated adult females. Results showed that the candidate
toxicants brought about marked reduction in testes relative weights, sperm
counts and motilities, activities of plasma and brain cholinesterases (ChEs) and caused histopathological alterations in testes of treated rats, all in comparison with those of
corresponding control group. Generally, the commercial preparation Runsave has
potentially greater toxic impact for rats than its components alone. Male rats
treated with Runsave and allowed to mate with receptive untreated females,
their reproductive capabilities were greatly diminished.