en تخصصي Special مقالات اصيل Original Article BACKGROUND<br> The aim of the presented study was to investigate the inhibitory effect of diltiazem on the microcirculation of the tissue flaps created in the delay phe-nomenon applied rabbits.<br> METHODS<br> The experiment was performed in Central Research Laboratory of Azerbai-jan Medical University, Baku, Azerbaijan in 2018. Ischemia model on the flaps were formed in 30 rabbits for experiment. The subjects were divided into three groups: I (control) group - consists of 10 rabbits who underwent ischemia model, but no medication had been used during the duration of the experiment; II (comparative) group - consists of 10 rabbits who underwent ischemia model, and during 14 d, with a daily dose of 60 mсg nitroglycerin had been applied; III (main) group - consists of 10 rabbits who underwent ischemia model, and during 14 d, with a daily dose of 45 mg diltiazem had been applied.<br> RESULTS<br> There was statistically significant difference between the control and the main groups when comparing the mean values of endothelial hyperplasia (P=0.001). However, we found a statistically significant difference when compared the mean values of the arterial vessel wall thickening in the main and the control groups (P=0.022); and the mean values of thrombosis in the main and the comparative groups (P=0.001).<br> CONCLUSION<br> With prescription of diltiazem, endothelial hyperplasia on microcirculatory system, the thickening of arterial vessel walls, the thrombosis in vessel&rsquo;s passage was rarely seen by statistical difference. The main achievement of our study was to discover the correlation between diltiazem and endothelial hyperplasia. Diltiazem, Experiment, Histology, Microcirculation, Pedicle flap 61 66 http://wjps.ir/browse.php?a_code=A-10-270-4&slc_lang=en&sid=1 Mahammad M Davudov 100319475328460010615 100319475328460010615 Yes Department of Oral and Maxillofacial Surgery, Azerbaijan Medical Universi-ty, Baku, Azerbaijan. Jamal Musayev 100319475328460010616 100319475328460010616 No Department of Pathology, Azerbaijan Medical University, Baku, Azerbaijan Adalat Hasanov 100319475328460010617 100319475328460010617 No Department of Pathology, Azerbaijan Medical University, Baku, Azerbaijan Hamid Reza Fathi 100319475328460010618 100319475328460010618 No Department of Plastic, Reconstructive and Aesthetic Surgery, Tehran Univer-sity of Medical Sciences, Tehran, Iran.