Effect of Inhaled Methanol on Pituitary and Testicular Hormones in Chamber Acclimated and Non-Acclimated Rats

摘要

Two experiments were conducted to evaluate the effects of methanol (MEOH) on the serum hormones associated with reproductive function in the male rat. First, rats were exposed to MEOH for 6 hs and killed immediately or 24 hs later. The effect of the handling associated with placing the rat in the exposure chamber was also evaluated by comparing hormonal changes in sham- and MEOH-exposed groups acclimated (A) for two weeks with groups that were not acclimated (N-A). At 6 h, serum LH in sham-exposed, NA rats was significantly greater than in sham-exposed, A rats. 5,000 ppm MEOH significantly reduced serum LH in the N-A rats, while 10,000 ppm significantly increased serum LH in the A rats. Serum FSH and testosterone (T) were not different at 6 h. At 24 h, serum LH in A rats exposed to 10,000 ppm MEOH was greater than sham-exposed rats. Also, concentrations of serum and interstitial fluid (IF) T in the N-A rats at 24 h was generally greater than that observed in A rats. Serum and IF T in the A rats exposed to 10,000 ppm was lower, while serum and IF T in N-A rats was greater after exposure to 5,000 ppm and 10,000 ppm, respectively. In a second experiment, groups of A and N-A rats were exposed to 5000 ppm MEOH for 1, 2 or 6 h and killed immediately. Serum LH, T and corticosterone concentrations in sham- and MEOH-exposed rats were similar at all time points. However, the concentrations of LH and T in the N-A rats were greater than A rats after 1 and 6 h exposure, while that of corticosterone was greater at 1 and 6 h.