The histopathological effects of levosimendan on liver injury induced by myocardial ischemia and reperfusion.

BACKGROUND: The aim of this study was to evaluate the histological and immunohistochemical effects of levosimendan on liver injury induced by myocardial ischemia and reperfusion (I/R) in a rat model. METHODS: Twenty-four male Wistar Albino rats were randomly divided into the four groups: Group C (Control, n = 6), Group I/R (n = 6), Group BI (I/R group treated with levosimendan before ischemia, n = 6), and Group AI (I/R group treated with levosimendan after ischemia, n = 6). Myocardial I/R was induced by ligation of the left anterior descending coronary artery for 30 min followed by two hours of reperfusion in I/R and I/R+Levosimendan groups. At the end of the study, liver tissue samples were obtained for histopathological and immunohistochemical examination. RESULTS: Masson Trichrome staining revealed significant hepatocyte degeneration and necrosis most marked in portal acinus Zone 3, especially around the central veins in Group I/R. Histopathological changes in Group AI were more similar to the changes in Group I/R. Milder hepatocellular degeneration was found in Group BI, when compared to groups I/R and AI. Immunohistochemical score was found to be significantly higher in Group I/R compared to groups C, BI and AI (p < 0.0001). The scores in groups BI and AI were found to be similar (p = 0.068). CONCLUSION: Levosimendan ameliorates liver injury induced by myocardial IR, especially when administered before induction of ischemia (Fig. 9, Ref. 37).

The protective effects of dexmedetomidine on liver injury-induced myocardial ischemia reperfusion.

PURPOSE: The aim of this study was to evaluate the effect of dexmedetomidine (100 µg/kg-ip) on liver injury-induced myocardial ischemia and reperfusion (IR) in rats. MATERIALS AND METHODS: Twenty-four Wistar Albino rats were separated into four groups. There were four experimental groups (Group C (Control; n = 6), Group IR (ischemia-reperfusion, n = 6), Group D (Dexmedetomidine; n = 6) that underwent left thoracotomy and received ip dexmedetomidine without IR administered via 100 µg/kg ip route 30 minutes before ligating the left coronary artery, and Group IR-D (IR-Dexmedetomidine; n = 6). A small plastic snare was threaded through the ligature and placed in contact with the heart. To produce IR, a branch of the left coronary artery was occluded for 30 min followed by two hours of reperfusion. However, after the above procedure, the coronary artery was not occluded or reperfused in the control rats. At the end of the study, liver tissue was obtained for histochemical and immunohistochemical determination.Some part of tissue samples were stained with Masson-trichrome for the evaluation of ultrastructural changes and inducible nitric oxide synthase (iNOS) expression was evaluated in other part of samples for immunohistochemical examination. RESULTS: Histopathological changes were detected in Group IR when compared with Group C. iNOS expression was found to be increased and stronger particularly in the vascular wall, perisinusoidal space and hepatocytes around vena centralis in this group compared to the control group. Perivascular oedema was detected to be decreased in Group IR-D compared to Group IR. It was also observed that the impairment in the radial arrangement of hepatocytes significantly recovered in Group IR-D. The immunoreactivity was found to be significantly decreased in the assessment of iNOS expression in the same group when compared with Group IR. CONCLUSION: Administration of dexmedetomidine ameliorates liver injury induced by myocardial ischemia and reperfusion (Fig. 8, Ref. 33).

Immunohistochemical and ultrastructural changes in rat fat tissue related to the local hCG injection.

OBJECTIVES: Recently, it has been observed that weight loss is accelerated by human chorionic gonadotropin (hCG) hormone preparation used for hypothalamic dysfunction in obesity treatment in both sexes. hCG is also used for in vitro fertilization and in treatment of hypogonadotropic hypogonadism. Our aim was to observe the ultrastructural changes caused by local injections of hCG made for purpose of weight loss and to present them to inform those receiving such therapy. MATERIALS AND METHODS: In our study, 10 obese female, 10 male obese, 10 non-obese female and 10 non-obese male rats were used. In each group, single dose of subcutaneous hCG injection has been applied to 7 rats for 5 weeks in 5 days of the week, and placebo has been applied to the remaining 3 rats. Following the injection, the tissues were evaluated morphologically, immunohistochemically and ultrastructurally. RESULTS: Leptin immunoreactivity was similar in all groups. When the adipose tissue samples were examined under electron microscope, they were observed to exhibit normal structure with organelles located around the nuclei and nucleoli, and no distinctive features were found among the groups. CONCLUSIONS: Administering hCG in addition to diet had no advantage on weight reduction in rats.

Effect of melatonin and time of administration on irradiation-induced damage to rat testes.

The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol) or melatonin administered 24 h before (10 mg/kg), immediately before (20 mg/kg) and 24 h after irradiation (10 mg/kg), all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05). Melatonin-treated groups showed less apoptosis as indicated by a considerable decrease in caspace-3 immunoreactivity (P < 0.05). Electron microscopic examination showed that all spermatogenic cells, especially primary spermatocytes, displayed prominent degeneration in the groups submitted to total body and abdominopelvic irradiation. However, melatonin administration considerably inhibited these degenerative changes, especially in rats who received abdominopelvic irradiation. Total body and abdominopelvic irradiation induced identical apoptosis and testicular damage. Chronobiological assessment revealed that biologic rhythm does not alter the inductive effect of irradiation. These data indicate that melatonin protects against total body and abdominopelvic irradiation. Melatonin was more effective in the evening abdominopelvic irradiation and melatonin-treated group than in the total body irradiation and melatonin-treated group.

Effect of melatonin and time of administration on irradiation-induced damage to rat testes

The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol) or melatonin administered 24 h before (10 mg/kg), immediately before (20 mg/kg) and 24 h after irradiation (10 mg/kg), all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05). Melatonin-treated groups showed less apoptosis as indicated by a considerable decrease in caspace-3 immunoreactivity (P < 0.05). Electron microscopic examination showed that all spermatogenic cells, especially primary spermatocytes, displayed prominent degeneration in the groups submitted to total body and abdominopelvic irradiation. However, melatonin administration considerably inhibited these degenerative changes, especially in rats who received abdominopelvic irradiation. Total body and abdominopelvic irradiation induced identical apoptosis and testicular damage. Chronobiological assessment revealed that biologic rhythm does not alter the inductive effect of irradiation. These data indicate that melatonin protects against total body and abdominopelvic irradiation. Melatonin was more effective in the evening abdominopelvic irradiation and melatonin-treated group than in the total body irradiation and melatonin-treated group.