Evaluation of the developmental neuroendocrine and reproductive toxicology of aluminium

Two experiments evaluating functional endpoints pertaining to the developmental neuroendocrine effects of aluminium in the rat are reported. A total of 31 timed mated dams were fed by daily gastric gavage 0, 5, 25, 50, 250, 500 or 1000 mg/kg body weight/day aluminium as a solution of aluminium lactate in distilled water from days 5 to 15 of gestation. The 390 offspring were evaluated for morphological and physiological parameters of reproductive functioning, including birth weight, anogenital distance (AGD), timing of vaginal opening, regularity of oestrous cycles, duration of pseudopregnancy (PSP), number of superovulated oocytes, and gonadal weight. No consistent or reproducible findings suggestive of toxic effect were found in the parameters of birth weight, AGD, timing of vaginal opening, duration of PSP, number of superovulated oocytes, and adult gonadal weight. A temporary increase in the proportion of aberrant oestrous cycles was detected during the first four cycles after vaginal opening, in the 250 mg/body weight/day group, with none by the fifth consecutive oestrous cycle. These results suggest that, apart from a transient disturbance of oestrous cycle regularity, aluminium does not have a developmental reproductive toxic effect.