RESUMO
Cadmium [Cd] is considered one of the most toxic trace elements in the environment. Kidneys have been used as standards for delimiting metal toxic concentration. However, recent reports indicate that chronic exposure to low doses of cadmium can cause pituitary gland and reproductive disturbances. Since the clinical manifestations of cadmium intoxication become evident only after a certain period of its accumulation, it is important to know if there is an early parameter to detect cadmium toxicity. The aim of this study was to evaluate pituitary gland dysfunction as an early parameter of chronic cadmium toxicity by comparing cadmium toxic effects on pituitary gland, as regard order of appearance, with renal function disturbances. This work was conducted on 66 adult male albino rats that were divided into three main groups; group I [negative control] consisted of 18 rats, group II [positive control group] consisted of 18 rats and received I ml distilled water daily by gavage and group III [Cadmium group]; consisted of 30 rats ad received Cd C12 in a dose of 0.1 mg/kg BW/daily by gavage. Each one of these three main groups was subdivided according to the experimental period into three equal subgroups; [a], [b] and [c]. The experimental period was one month for subgroups Ia, IIa, and IIIa, two months for subgroups Ib, IIb and IIIb and three months for subgroups Ic, IIc and IIIc. Estimation of FSH, LH, creatinine, BUN, Beta2- microglobulins [beta 2-MG] serum levels and Cd tissue level in the kidney and pituitary gland was carried out together with histological examination of pituitary gland and kidneys. The results of this study show that admium has induced toxic effects in both pituitary gland and kidneys with cadmium accumulation in both organs being more in the renal tissues. However, pituitary sysfunction appeared earlier than renal dysfunction. These findings suggest that pituitary gland may be more sensitive to cadmium toxicity than the kidney. So, further researches are recommended for evaluation of estimation of pituitary functions for early detection of chronic cadmium toxicity. Also, strictly enforced limits of cadmium in foods are necessary for an overall decrease in exposure. Moreover, persistence in the environment of this metal requires a long-term move toward minimizing human exposure through environmental measures and preservations of lower cadmium levels wherever possible