To investigate the toxic effect of terephthalic acid(TPA)on testicular functions of rats, male Sprague-Dawley rats were orally administered TPA in diet at the levels 0(control),0.2,1 and 5%for 90 days.Testicular functions were assessed by histopathology,testicular sperm head counts,daily sperm production, sperm motility (measured by computer-assisted sperm analysis, CASA), biochemical indices(marker testicular enzymes), and serum testosterone.Oral feeding with terephthalic acid did not cause body and testes weight loss in TPA-treated groups.Histopathologically,damages of spermatogenic cells and Sertoli cells were observed by electron microscope,testicular sperm head counts, daily sperm production,and activities of sorbitol dehydrogenase (SDH) were decreased significantly in the 5% TPA group.The motility of spermatozoa was reduced significantly in all treated groups,which was correlated with administration doses. Serum testosterone concentrations were not declined in treated groups.In conclusion,TPA can cause impairment of testicular functions.The primary sites of action may be spermatogenic cells and Sertoli cells.The results of the present study provide first information of TPA on testicular functions in male rats.

A cross-sectional study of 68 petrochemical workers(23had never smoked [E/NS],45 were current smokers [E/S]) and 130 subjects with no known history of exposure to petrochemicals (49 had never smoked [NE/NS], 81 were current smokers [NE/S]) was conducted to assess the effect of occupational exposure to petrochemicals and smoking on semen quality.In-person interviews revealed occupational history,smoking habit,and lifestyle.Semen parameters such as volume,viability,sperm forward progression rate,sperm density,and total sperm count were determined for all subjects.The results show that the E/NS workers had a lower sperm forward progression rate (P<0.05) compared with controls (NE/NS). Individuals in the NE/S group showed a significant inverse relationship between years smoked and sperm density (r=-.24,P<0.05). The data also revealed that cigarette smokers who had worked in a petrochemical plant had significantly poorer quality semen,including sperm density,total sperm count,and forward progression rate, compared with the control (NE/NS)group (P<0.01). Furthermore, there was a significant inverse correlation between combined exposure and smoking years,and sperm density (r=-.28, P<0.05). These findings suggest that occupational exposure to petrochemical compounds may aggravate the adverse effect that smoking has on semen quality.