Aras Part Medical International Press International Journal of Medical Parasitology and Epidemiology Sciences 2766-6492 1 2 2020 04 01 Evaluation of Tissue Changes in the Hearts of Rats Infected with Toxoplasma Gondi 31 34 10.34172/ijmpes.2020.12 EN Hamed Najjare-Aghdam Arash Khaki https://orcid.org/0000-0002-4678-4002 Journal Article 10.34172/ijmpes.2020.12 2019 09 25 2020 03 21 Introduction: Toxoplasma gondii is a protozoan parasite that is globally widespread and infects humans and animals. Obligate intracellular parasites enter many organs and tissues through the bloodstream, where they invade and proliferate into cells, eventually destroying them. The aim of this study was to evaluate the extent of cardiac tissue changes in rats infected with T. gondii. Methods: Male Wistar rats (n=30) were allocated to three groups as follows: control group (n=10), T1 group that received 0.3 mL of T. gondii tachyzoite (IP) (n=10), and T2 group that received 0.6 mL of T. gondii tachyzoite (IP) (n=10). However, the control group just received an equal volume of distilled water daily (IP). Animals were kept in standard condition. Forty days after inducing toxoplasmosis, heart tissues of rat in all groups were removed and prepared for histopathological examinations of heart tissue under optical microscopy after hematoxylin and eosin staining and calculation of heart tissue weight. Results: Heart tissue weight significantly decreased in groups that received 0.3 and 0.6 mL of T. gondii tachyzoite in comparison to control groups. In histopathological studies of heart tissue under optical microscopy, atrophy and necrosis were observed in heart tissues in T. gondii groups. Conclusion: Since this parasite caused necrosis of heart cells in rats in our study, it is suggested that in preventing T. gondii infection, health measures should be taken to promote human and animal health.