Effects Of Sub-Chronic Aluminum Exposure On The Reproductive Toxicity In Female Rats

Sixty healthy female Wistar rats (5weeks old) weighed110g-120g were randomly allocated into control-group (GC), low-dose group (GL), medium-dose group (GM) and high-dose group (GH). They were acclimatized for one week before the test, and were orally exposed to0,64.18,128.36and256.72mg/kg body weight aluminum trichloride (AlC13) in drinking water for120days to copy the model of sub-chronic aluminum exposure in rats, respectively. Clinical symptom, body weights, microstructure and ultrastructure of the ovaries were observed. The levels of E2, P, T, LH and FSH in serum were detected using125I radioimmunoassay (RIA) kits. The activities of ACP, ALP, SDH and ATPase were detected by spectrophotometry. The contests of Fe, Cu and Zn in ovaries were measured using flame atomic absorption spectrophotometry and Al in ovaries and serum were were measured using graphite furnace atomic absorption spectrophotometry. The protein expressions of FSHR and LHR in ovaries were detected by immunohistochemistry. The results showed as follows:1Aluminum (A1) exposure model was made successfully in the rats by clinical symptom and physical change.2The body and ovary weights both decreased with the increase of the dose of Al administration (P<0.05; P<0.01), while there was no significant difference in the organ coefficient of ovary. It was proved that aluminum exposure could inhibit rats’growth and development.3Under optical microscope, blurred ovarian granulosa cells, matrix adhesion and fibrosis in the cytoplasm of Al-treated ovaries, more infiltrating stroma inflammatory cells, pyknotic, chipped necrotic and liquid in corpus luteum organization cells and stromal cells, atresia follicle and hemorrhagic were observed. Under electron microscope, scattered and highly concentrated chromatin at nuclear membrane edge, weazen nuclear membrane, sunk and chipped nucleolus, typical and crescented apoptosis of corpus luteum granulosa cells were observed. Also, much lipid drops and phagolysosome, decreased rough endoplasmic reticulum, swollen and fused mitochondria were observed in intracytoplasm. It was proved that Al exposure could cause rat ovary structure damage. 4The contents of A1were higher in ovary and serum, copper (Cu) was higher (P<0.05; P<0.01) and zinc (Zn) and iron (Fe) were lower (P<0.05; P<0.01) in ovary of rats in Al-treated groups than that in GC. It indicated that A1could accumulate in the ovary following long-time A1exposure. A1could interrupte the metabolism of trace element, and inhibited the reproductive function of ovary of rats in A1-treated groups.5Compared with GC, the activities of ALP, ACP, SDH, and ATPase were decreased (P<0.05; P<0.01), it was proved that Al exposure can interfere energy metabolism of reproductive system in female rats ovaries.6The serum levels of E2, P, LH and FSH in GH were decreased significantly than GC (P<0.01). Compared with GC, T level was increased significantly in GL and GM (P<0.05; P<0.01) and increased no significant in GH (P>0.05). The protein expressions of FSHR and LHR in GM and GH were decreased than GC. The results indicated that Al exposure disturbed the ovary secretory function, reduced the combination of the hormones and receptors, and decreased the hormone physiological function.