Considering the importance of leptin andghrelin effects in regulation of the hypothalamic-pituitary-gonadal axis, the objectiveof this study was to investigate the influence of obesity and centrally applied ghrelinon immunohistochemical appearance and quantitative morphology of the pituitaryfollicle-stimulating hormone (FSH) and luteinizing hormone (LH) producing cells inadult male rats. The gene discussed is PLOD1; the disease is obesity due to melanocortin 4 receptor deficiency.