Effect of melatonin on antioxidant capacity, inflammation and apoptotic cell death in lung tissue of diabetic rats.

PURPOSE: To investigate the effects of melatonin on antioxidant capacity, inflammation and apoptotic cell death (through expression of cleaved-caspase 3) in lung tissue samples of diabetic rats. METHODS: Thirty male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control group) was made up of healthy rats. Group 2 (diabetes group) received streptozotocin at a dose of 50 mg/kg/day for 5 days.Group 3 (diabetes plus melatonin group) received streptozotocin at a dose of 50 mg/kg/day for 5 days and then they received melatonin at a dose of 20 mg/kg/day between 28thand 35thdays of the study. RESULTS: Tissue MDA and MPO levels were found to be significantly higher in diabetes group compared to control group (p<0.05) whilst administration of melatonin was found to significantly lower this increase down to normal levels (p<0.05). Bronchus associated lymphoid tissue (BALT) was more severe in diabetics whereas administration of melatonin alleviated this hyperplasia. Cleaved caspase 3 activity was severe in hyperplastic BALT in diabetic rats however in lowered down to moderate level when melatonin was administered. CONCLUSION: The melatonin caused an increase in antioxidant capacity and decreased the expression of cleaved-caspase 3.

The effect of desflurane and propofol protocols on preconditioning.

BACKGROUND: Preconditioning is one of the most powerful mechanisms preventing the myocardial ischemic damage that occurs during coronary artery bypass grafting. OBJECTIVES: We aimed to investigate the effects of different propofol and/or desflurane administration protocols in terms of the prevention of ischaemia-reperfusion damage. MATERIAL AND METHODS: Ninety patients, aged > 18 years, American Society of Anesthesiologists (ASA) category III, scheduled to undergo primary elective coronary artery bypass grafting (CABG), were included in the study. During maintenance, the patients in group 1 (n = 30) received a propofol infusion (5-6 mg/kg/h) combined with a fentanyl infusion (3-5 mcg/kg/h); the patients in group 2 (n = 30) also received a propofol infusion (5-6 mg/kg/h) combined with a fentanyl infusion (3-5 mcg/kg/h), but they were also given 6% desflurane inhalation for 15 min both before cross-clamping of the aorta and after removal of the clamp; the patients in group 3 (n = 30) received a propofol infusion (2-3 mg/kg/h) combined with a fentanyl infusion (3-5 mcg/kg/h) and received the continuous 6% desflurane inhalation. Blood samples were drawn in the preoperative period (S1), during cardiopulmonary bypass, before cross-clamping the aorta (S2), after removal of the cross-clamp (S3) and 24 h after the operation (S4). RESULTS: All groups were similar in terms of age and BMI (p > 0.05). TNF-α levels were higher at S3 compared to S1, S2 and S4 (p > 0.001). The TNF-α levels at S4 were lower in group 3 than those in group 1 and group 2 (p < 0.05). In all groups, h-FABP levels showed an increase in S3 but were significantly lower at S4 (p < 0.05). In group 3, h-FABP levels at S2 and S3 were significantly lower than those in group 1 (p < 0.05). There was a moderate correlation between h-FABP and TNF-α levels (Spearman's rho = 0.472, p < 0.001). CONCLUSIONS: On the basis of the measurement of h-FABP and TNF-α, low-dose propofol and continuous desflurane inhalation provide more effective preconditioning than propofol alone or a short course of desflurane in patients undergoing CABG.

Melatonin Attenuates Contrast-Induced Nephropathy in Diabetic Rats: The Role of Interleukin-33 and Oxidative Stress.

BACKGROUND: Inflammation and oxidative stress (OxS) contribute to the pathogenesis of diabetic kidney disease (DKD) and contrast-induced nephropathy (CIN). Patients with DKD were found to be more prone to CIN. Interleukin-33 (IL-33) is a proinflammatory cytokine, but its role in DKD and CIN is unknown. METHODS: Thirty male Sprague-Dawley rats were enrolled. The first group was comprised of healthy rats (HRs), whereas the other four groups were made up of diabetic rats (DRs), diabetic rats with contrast-induced nephropathy (CIN + DRs), melatonin-treated diabetic rats (MTDRs), and melatonin-treated CIN + DRs (MTCIN + DRs). All groups except the HRs received 50 mg/kg/day streptozotocin (STZ). CIN + DRs were constituted by administrating 1.5 mg/kg of intravenous radiocontrast dye on the 35th day. MTDRs and MTCIN + DRs were given 20 mg/kg/day of intraperitoneal injection of melatonin (MT) from the 28th day for the constitutive seven days. RESULTS: We observed increased IL-33 in the kidney tissue following induction of CIN in DRs. To determine whether MT is effective in preventing CIN, we administered MT in CIN + DRs and demonstrated that kidney tissue levels of OxS markers, inflammatory cytokines, and IL-33 were significantly diminished in MTCIN + DRs compared with other groups without MT treatment (p < 0.05). CONCLUSION: Inhibition of IL-33 with MT provides therapeutic potential in DKD with CIN.