Background: Toluene is an environmental chemical pollutant and widely used as organic solvent and in production of many industrial products. It has systemic toxic effects on many organs as liver, kidney and the central nervous system and cause immune dysfunction. It can affect nerve myelination and cross the blood-brain barrier. Little is known about the exact effect of toluene exposure on the cells of anterior pituitary and no adequate studies were found about the effect of toluene on the morphological and histological structure of the pituitary cells.
Aim: To assess the ultra structural of the pars distalis after toluene exposure. And to correlate any biochemical changes with the histological alteration as a trial to know the possible mechanism behind these changes.
Materials and Methods: 20 adult male albino rats were divided into control group consisted of 10 rats and toluene exposed group 10 rats were exposed once a day to vapors of toluene (1000 ppm) for 15 minutes for 45 days. Blood samples were taken from the heart chambers of for assessment of the thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH), luteinizing hormone (LH), adrencorticotrophic hormone (ACTH), growth hormone (GH) and prolactin. The anterior lobes of pituitary glands were immediately dissected out. Each specimen was separated into two parts; one processed and stained with hematoxylin & eosin and the other part was examined by electron microscope.
Results: Biochemical: in the toluene-exposed group there was significant reduction in plasma level of GH, TSH, FSH and LH hormones and non-significant reduction in ACTH prolactin.
Microscopic: the exposed group cells show complete loss of normal architecture in many areas and had vacuolated cytoplasm, shrunken asymmetrical nucleus with more thickened chromatin and few secretory granules.
Conclusion: The toluene exposure induced morphological changes in most of cells of pars distalis and their secreted hormones