CHRONIC CARBON MONOXIDE EXPOSURE AND UTERINE MORPHOLOGY: A DOSE-RESPONSE EXPERIMENTAL STUDY

Abstract

 Background. Carbon monoxide (CO) is a widespread environmental 
toxicant produced by incomplete combustion. Via carboxyhemoglobin formation and mitochondrial inhibition it generates oxidative stress; however, its concentration dependent effects on uterine morphology remain incompletely characterised. Aim. To evaluate dose-dependent morphological and morphometric changes in uterine tissues  following chronic CO inhalation in a rat model. Methods. Forty female Wistar rats were divided into control and three CO-exposed groups (50, 100, 200 ppm; 4 weeks; n = 10 each). Uterine sections stained with haematoxylin–eosin were evaluated morphometrically (endometrial thickness, gland count per mm²). Results. CO caused progressive, concentration-dependent reductions in endometrial thickness (420 → 285 µm) and gland number (28 → 14 per mm²); all changes were significant versus control (p < 0.05). Conclusion. Chronic CO exposure induces dose-dependent structural deterioration of the uterus consistent with hypoxia- and oxidative-stress-mediated  endometrial atrophy, posing a meaningful risk to female reproductive health.