Objective: During the last decades, the environmental contamination by lead generated by human activities has become an evident concern. So, effects of lead acetate were studied on histomorphometric structure of ovary during POSTNATAL development in Wistar rats.Materials and Methods: The female pups randomly divided in control and experiment groups. The mothers of experiment groups received 100 and 300 mg/L/day lead acetate via drinking water during lactation. The ovaries of pups were removed at 3 months after birth; their weights recorded and were fixed in Bouin’s solution. Followed tissue processing, 5-6 µm paraffin sections were stained with haematoxylin-eosin, and then, number, diameter and surface area of primordial, primary, secondary, graffian and atretic follicles were estimated in control and experiment groups.Results: The results showed that the means of ovary weights in low and high doses groups decrease at 3 months after birth in comparison with control group. Microscopic results indicated that number of primordial and atretic follicles increased significantly (p<0.05) at puberty in low and high doses groups in comparison with control group. Also, mean diameter and surface area of secondary and graffian follicles decreased significantly (p<0.05) in high dose group.Conclusion: Present study shows that lead acetate affect prepubertal ovarian follicle development and can decrease fertility and reproductive efficiency of female Wistar rats.

Introduction: Acute or chronic lead poisoning in animals and humans is well documented. Moreover developing brain appears to be especially vulnerable to lead neurotoxicity, and the cerebellum has been described as a favorable target for lead poisoning. The aim of present study was to evaluate the effects of neonatal lead EXPOSURE (POSTNATAL period of cerebellar development) on the motor behavior and cerebellar cortex in male rats.Methods: In this study, new born male rats were randomly divided into two groups: Control (n=10) and lead EXPOSURE groups (n=10). Rat pups in lead EXPOSURE group received 8 mg/kg lead acetate intraperitoneally daily for 21 days. Behavioral studies including rotarod and open field tests were performed in POSTNATAL days 31–33 (PD) and histological study was performed after completion of behavioral measurements in POSTNATAL day 33.Results: Result of the present work indicated that lead could impair rotarod performance in sessions 1, 2 (P<0.01) and in sessions 4, 6 (P<0.05). Also, open field test demonstrated that number of crossing and rearing significantly decreased in lead EXPOSURE group as compared to control group (P<0.05). Histological analysis also indicated that number of purkinje cells significantly reduced in lead treated group as compared to control group (P=0.001).Conclusion: These results suggested that chronic POSTNATAL lead EXPOSURE had toxic effect on the cerebellum and can induce dysfunctions in motor and exploratory behaviors.

Background: Lead is a heavy metal with no apparent biological function. The widespread environmental contamination, the propensity to cause a wide spectrum of toxic effects and the number of individuals affected worldwide makes this ubiquitous neurotoxicant a public health problem of global magnitude. The nervous system is the primary target for the low levels of lead EXPOSURE and the developing brain appears to be especially vulnerable to lead neurotoxicity.Objectives: The aim of present study was to evaluate the effects of neonatal lead EXPOSURE on spatial learning and memory in Morris water maze.Materials and Methods: In this experimental study, 30 new born male rats were randomly divided into two groups: Control and lead EXPOSURE groups. Rat pups in lead EXPOSURE group received 8 mg/kg lead acetate intraperitoneally daily for 21 days. Then, rats trained with 6 trials per day for 6 consecutive days in the water maze at 36th POSTNATAL day (PD). Twenty four hours after ending of training, a probe test was done to measure memory retention.Results: Results of this study demonstrated that EXPOSURE to lead could affect learning as indicating by significant differences in escape latency and traveled distance between 2 groups during 6 days of training. Lead EXPOSURE group exhibited significantly higher escape latency and distance traveled during training trials compared to control group. Also, lead EXPOSURE rats had higher platform location latency than control group during probe trial (P<0.05).Conclusions: These data suggests that lead EXPOSURE during early POSTNATAL period of brain development causes impairment in spatial learning and memory.