Gravimetric and Histologic Changes in Rat Testes Following Oral Congo Red Administration

Abstract

Extremely high dose (g/kg) of Congo red has been reportedly used in assessing the testicular effects of this dye in mice and rats based on prenatal exposure. In our experience, low doses (mg/kg) have produced hepatotoxic effects in chickens and serum enzyme inhibition in rats following oral and intraperitoneal administration. Thus the objective of this study was to find out if our low doses can cause testicular toxicity. Hence the effect(s) of orally administered low doses of Congo red (CR) on rat testes was investigated using gravimetric and histologic methods. When compared to CR-free rats, the testes weights of rats exposed to 10, 20, 30 and 40mg CR/kg body weight (once a week for 6 weeks) significantly decreased (p < 0.05). Histological examination of the testes revealed the presence of disrupted tubular basement membranes in rats exposed to 10, 20, 30 and 40mg CR. Changes in the two parameters studied were not noticed in rats exposed to 5mg CR but became readily evident as the dose increased. The results presented here suggest that low doses of Congo red are able to induce adverse testicular effect in rats.

Key words: Congo red, rat testicular changes

Journal of Medical Laboratory Science Vol.12(2) 2003: 42 - 46