The Effects Of Cadmium On Submandibular Gland And The Protective Effects Of Testosterone In Male Rats

Objective Investigating the effects of cadmium and the protection oftestosterone propionate on submandibular gland of male rats. Methods Thirty-five male adult Wistar rats were randomly dividedinto three groups and were treated with intraperitoneal injection, as follows:(1) control: physiological saline, (2) Cd: CdCl2(4 ㎎/㎏×1), (3) Cd + T:Cd(4 ㎎/㎏×1)+T(5 ㎎/㎏ ×3) . Thereafter, the rats were killed at 24h, 3, 7,15, 30d after treatment. The cadmium concentrations in submandibulargland were measured by flame mode of atomic absorptionspectrophotometry . Meanwhile, the morphologic changes of GCT cellswere observeded by light and transmission electron microscopy. In addition,the expression of AR were determined by immunohistochemical SABCmethod and were semi-quantitatively analysed by image analysis. Results (1) After Cd treatment, no obvious lesions were observed insubmandibular gland by light microscope. The transmission electronmicroscopic observation showed that the main ultrastructural changes afterCd treatment included swelling or vacuolation of mitochondria , increase ofmyelin figures in GCT cells , and swelling of mitochondria in theendothelial cells of peritubular capillaries. The changes above were mostprominent at 7-15d. In some GCT cells, swelling of the cytoplasm andslight karyolysis were also found. The morphology of GCT cells didn'trecovery to normal yet after 30d. On the other hand, the ultrastructurallesions of GCT cells in Cd+T group were gentle. (2) Compared withcontrol group, the cadmium concentrations in both Cd and Cd+T groupwere significantly increased, and reached to the highest level within 3-7d.Although the cadmium concentrations in Cd+T group were lower than thatin Cd group, there was no significant difference between the two groups. (3)Specific immunoreactivity of AR in submandibular gland appeared innuclei and plasma of acini, GCT, striated and excretory duct. Theimmunoreactivity level of AR had decreased at 24h after Cd treatment, andwas to the lowest level at 7d. 30d after Cd treatment, they were still lowerthan that in control group .The immunoreactivity level in Cd+T group werehigher than that in corresponding Cd group, and had significant differencebetween them at 24h,3,7d . Conclusions The present results indicate that the earlierultrastructural damage of GCT was related to the direct action of cadmium ,the decrease of androgen and androgen receptor might aggravate thedamage at later stages. To some extent, testosterone pretreatment couldprevent toxicity of cadmium on submandibular gland .