Age-sex dimorphisms in the estimation of median lethal dose (LD50) of lead diacetate in rabbits using up-and-down procedure (Arithmetic method)

Lead had been known to be toxic since pre-antiquity. It causes neurodevelopmental, cardiovascular and renal pathologies. Other toxicological studies of lead (Pb) salts are studied in laboratory animals such as rat, mice, hamsters, rabbits and monkeys; however, there is paucity of information on the median lethal dose (LD50) of Pb salts in rabbits especially when used as a model for molecular studies of Pb toxicity. In view of this, oral LD50 of lead (Pb) diacetate [Pb(CH3COO)2] was determined in both young (6 weeks old, weighing 0.40 ± 0.03 kg) and adult (34 weeks old, weighing 1.63 ± 0.10 kg), male and female New Zealand White (NZW) rabbits (Oryctolagus cuniculus) using the revised arithmetic method of Up-and-Down Procedure (UDP). The estimated LD50 of Pb diacetate in young male and female NZW rabbits was 1214.20 ± 275.80 and 1214.20 ± 275.80 mg/kg body weight respectively. Also, the LD50 of the adult male and female rabbits was 1503.30 ± 342.90 and 1792.50 ± 354.40 mg/kg body weight respectively. Similarities in the estimated LD50 of the young rabbits could be attributed to poorly developed xenobiotic metabolic processes. Sex-dimorphism in the toxicity of Pb diacetate was observed in the adult animals, where the male animals were found to be more sensitive to the toxicant than the female. Hence, Pb diacetate is moderately toxic in NZW Rabbits according to “Gosselin, Smith and Hodge scale” of toxicity rating.Keywords: Arithmetic mean, Dimorphism, Dose, Lead, Rabbits, Sex, Toxicit