Effect of Angiotensin II Receptor-Blocker (ARB) Losartan on the Myocardium of Streptozotocin Induced Diabetic Rats.: Histological and Histochemical Study

Badawy Khair, Nadia Said; Mansour, Magda Ahmed; Helmy, Asmaa Fawzy; A Abdelaziz, Seham Ahmed

doi:10.21608/ejh.2022.161385.1768

Effect of Angiotensin II Receptor-Blocker (ARB) Losartan on the Myocardium of Streptozotocin Induced Diabetic Rats.: Histological and Histochemical Study

Document Type : Original Article

Authors

¹ histology department.faculty of medicine,menuofiya university

² Histology and cell biology department, Faculty of Medicine-Menoufia University

³ histology and cel biology

⁴ histology an cell biology -faculty of medicine menoufia university

10.21608/ejh.2022.161385.1768

Abstract

Introduction: Diabetes Mellitus (DM) is a common endocrine and metabolic condition. It is one of the most rapidly growing diseases worldwide, and is a prime cause of excess cardiovascular morbidity and mortality in populations. The chronic hyperglycemia of diabetes is associated with long-term damage, dysfunction, and failure of various organs especially the eyes, kidneys, nerves, heart, and blood vessels. Losartan is an angiotensin II type one (AT1) receptor antagonist authorized for arterial hypertension (HTN) treatment. Losartan is also utilized to avoid renal damage in diabetics and those with decreased ejection fraction (EF) due to heart failure
Objective: This research objects to determine the potential protective impact of Losartan administration on the induced diabetic myocardium and aorta of adult male Sprague-Dawley rats.
Materials and Methods: Sixty adult male Sprague-Dawley rats were utilized in the present research. They were allocated into four groups: group I (control group), group II (Losartan received group) they were received losartan 30 mg/kg/day, group III (diabetic group) induction of DM by a single intraperitoneal injection of 65 mg/kg STZ solution freshly mixed in 0.1 M citrate buffer and group IV (diabetic with Losartan group). After 8 weeks, the animals from all groups were anaesthetized and blood samples were obtained for biochemical study. The heart and aorta were dissected, and histological, immunohistochemical and electron microscopic studies were conducted on the tissues.
Results: Diabetic myocardium revealed histological alterations as fragmented muscle fibers, small darkly stained pyknotic nuclei, cellular infiltration and a significant elevation in collagen fibers percentage area with marked biochemical changes as increased plasma level of MDA. Administration of Losartan to diabetic rats made ameliorating effect on the disturbed structure, decreased the elevated tissue malondialdehyde (MDA) levels and increased the reduced activities of the enzymatic antioxidants superoxide dismutase (SOD), and catalase (CAT) in cardiac tissue. Diabetic group exhibited a significant increase (P<0.001) in collagen fibers mean percentage area, number of Caspase-3 positive cells, and a significant decrease (P<0.001) in the intensity of eNOS immunoreaction in the myocardium tissue of rats than the control group. While diabetic group treated with losartan exhibited a significant decrease (P<0.001) in collagen fibers mean percentage area, the number of Caspase-3 positive cells, and a significant increase (P<0.001) in the intensity of eNOS immunoreaction than diabetic group.
Conclusion: Losartan has a protective effect on the biochemical, histological, and morphometric changes of the myocardium and the aorta of diabetic rats.

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