Toxicological Effects of Simultaneous Exposure to Toluene and Noise on some Sexual and Stress Parameters in New Zealand White Rabbits

Noise and toluene are among the numerous physical and chemical pollutants that can induce adverse effects on different body tissues and systems; nevertheless, most studies have only experimented the auditory changes induced by co-exposure to them. The present in-vivo study aimed to examine the endocrine effects of co-exposure to toluene and noise on the testes and adrenal glands. In this experimental study, 24 healthy male New Zealand White rabbits were used. The noise intensity was 100 dB (white noise) and the toluene concentration was 1000 ppm for two consecutive weeks. The luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, cortisol and adrenocorticotropic hormone (ACTH) were measured using the enzyme-linked immunosorbent assay (ELISA) method. The hematoxylin and eosin stain method (H&E) was performed for the histopathological analysis. Comparing different parameters in different groups on post-exposure days was carried out using GEE (generalized estimating equations) method. The results indicated that noise and toluene increased cortisol, LH and FSH levels during different days after the exposure. Exposure to toluene and noise made vacuolization and reduction of primary spermatogonial cells in the testes. Moreover, lymphocyte infiltration, congestion, swelling and vacuolization were detected in adrenal glands through exposure to toluene and noise. Toluene and noise induced different destructive effects on the endocrine system. More studies are required to elucidate other endocrine changes induced by exposure to toluene and noise.