Effect of Ethephon on testicular pathology and apoptosis of spermatogenic cell in offspring male rats

Abstract

Objective To investigate the effect of Ethephon on the testis pathological structure and apoptosis of spermatogenic cell in offspring male rats. Methods Twenty-four healthy female SD rats of 45 days old were randomly divided into control group, low-dose Ethephon group, medium-dose Ethephon group and high-dose Ethephon group according to body weight.The male rats of the same age were selected to mate with female rats.The rats were fed with Ethephon solution of different concentrations or 9 g/L saline every day, and they were continued to be fed with Ethephon during pregnancy and lactation.At the age of 7 days and 14 days, 10 offspring male rats were randomly selec-ted from each group and were put to death.The testicular tissue was stained with HE, and the morphological changes in the testis were observed with light microscope; the apoptotic cells were labeled with terminal deoxynucleotidyl transfe-rase dUTP nick-end labeling (TUNEL method) and the apoptosis index(AI) of testis spermatogenic cells was detected with fluorescence microscope. Results At the age of 7 days, the testis internal structure of the control group developed well, and the spermatic tubules were neatly and compactly arranged.In the low-dose Ethephon group, the seminiferous tubules of the testis were slightly smaller and the spermatogenic cells were loosely arranged compared with the control group.In the medium-dose Ethephon group, the testis seminiferous tubules were slightly disordered and the cell gap increased.In the high-dose Ethephon group, the testis development was poor, the diameter of seminiferous tubules decreased significantly, and the spermatogenic cells arrangement was in disorder.There was no statistically significant difference in spermatogenic cell AI between the low-dose group [(0.54±0.10)%] and the control group[(0.53±0.09)%] (P>0.05), while the spermatogenic cell AI in the medium-dose Ethephon group [(0.63±0.11)%] and the high-dose Ethephon group [(0.81±0.06)%] were higher than that in the control group, thus there exists a statistically significant difference (all P<0.01). The spermatogenic cell AI in the low-dose Ethephon group [(0.54±0.10)%] was lower than that in the medium-dose Ethephon group [(0.63±0.11)%], and the difference was statistically significant (P<0.05). The spermatogenic cell AI in the medium-dose Ethephon group was higher than that in the high-dose Ethephon group, and the difference was statistically significant (P<0.01). At the age of 14 days, the spermatogenic cells AI in control group, low-dose Ethephon group, medium-dose Ethephon group and high-dose Ethephon group were (0.54±0.08)%, (0.65±0.11)%, (0.77±0.11)%, and (0.88±0.10)% respectively, and the spermatogenic cells AI in all groups increased gradually, in which the differences were statistically significant (all P<0.01). Conclusions Excessive dose of Ethephon can induce pathological changes in testicular tissue and increase the apoptosis of spermatogenic cells, resulting in low fertility of offspring rats. Key words: Ethephon; Testis; Spermatogenic cell; Apoptotic index