Effects of pyrethroid insecticide ICON (lambda cyhalothrin) on reproductive competence of male rats.
OBJECTIVE
To assess the effect of ICON (trade name of lambda-cyhalothrin) on sexual competence and fertility of male rats.


METHODS
Male rats were gavaged daily for 7 consecutive days with different doses of ICON (63 mg/kg and 100 mg/kg) or vehicle (distilled water). Their sexual behaviour and fertility were evaluated at different time points during treatment and post-treatment using receptive females.


RESULTS
Treatment had no effect on fertility, but sexual competence was seriously impaired: libido (assessed in terms of pre-coital sexual behaviour, and numbers of mounting, intromission and ejaculation), sexual arousability/motivation (in terms of latencies for mounting, intromission and ejaculation), sexual vigour (judged by frequencies of mounting and intromission or copulatory efficiency). In addition, ICON suppressed intromission ratio, indicating erectile dysfunction. These effects on sexual function had a rapid onset and was reversible. ICON-induced sexual dysfunction was mediated by multiple mechanisms, mainly toxicity, stress, sedation and possibly via GABA and dopaminergic systems.


CONCLUSIONS
Exposure to ICON may cause sexual dysfunction in male rats.
Ratnasooriya
W D
WD
Department of Zoology, University of Colombo, Sri Lanka. dapput@sltnet.LK
Ratnayake
S S K
SS
Jayatunga
Y N A
YN
D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003307:Copulation / Q000187:drug effects*; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D004906:Erythrocyte Count; D005260:Female; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007248:Infertility, Male / Q000139:chemically induced*; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009570:Nitriles; D011722:Pyrethrins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012472:Salivation / Q000187:drug effects
D006993:Hypnotics and Sedatives; D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C037304:cyhalothrin