Changes in Serum Levels and Gene Expression of PGC-1 alpha in The Cardiac Muscle of Diabetic Rats: The Effect of Dichloroacetate and Endurance Training
CELL JOURNAL
Authors: Nasab, Hamed Rezaei; Habibi, Abdol Hamid; Nikbakht, Masoud; Rashno, Mohammad; Shakerian, Saeed
Abstract
Objective: Physical activity leads to changes in the level of gene expression in different kinds of cells, including changes in mitochondrial biogenesis in the myocardium in diabetic patients. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) is a gene that plays an important role in regulating mitochondrial biogenesis. The purpose of this study was to investigate changes in serum levels and cardiac muscle expression of PGC-1 alpha in diabetic rats in response to the administration of dichloroacetate (DCA) and endurance training. Materials and Methods: In this experimental study, 64 male Wistar rats were selected and randomly divided into eight groups after induction of diabetes with streptozotocin (STZ). The endurance training protocol was performed on a treadmill for 6 weeks. Intraperitoneal injection of DCA of 50 mg/kg body weight was used for the inhibition of Pyruvate Dehydrogenase Kinase 4 (PDK4) in the myocardium. Gene expression were measured using real-time polymerase chain reaction (PCR). One-way ANOVA and Tukey's test were used to statistically analyze the data. Results: The results of the study showed that PDK4 gene expression in the endurance training group, diabetes+endurance training group, diabetes+endurance training+DCA group and endurance training+DCA group was higher compared to the control group. Expression of PGC-1 alpha was higher in the endurance training group compared to the control group but was lower compared to the control group in diabetes+endurance training+DCA group and diabetes+DCA group (P<0.05). Conclusion: Considering that PGC-1 alpha plays an important role in mitochondrial biogenesis, it is likely that by inhibiting PDK4 and subsequently controlling oxidation of fatty acid (FA) in the heart tissue, oxidative stress in the heart tissue of diabetic patients will be reduced and cardiac efficiency will be increased.
Active management of severe hyponatraemia is associated with improved mortality
EUROPEAN JOURNAL OF ENDOCRINOLOGY
Authors: Garrahy, Aoife; Cuesta, Martin; Murphy, Brian; O'Reilly, Michael W.; Tormey, William P.; Sherlock, Mark; Thompson, Chris J.
Abstract
Objective: Severe hyponatraemia (plasma sodium concentration, pNa <120 mmol/L) is reported to be associated with mortality rates as high as 50%. Although there are several international guidelines for the management of severe hyponatraemia, there are few data on the impact of treatment. Design and methods: We have longitudinally reviewed rates of specialist input, active management of hyponatraemia, treatment outcomes and mortality rates in patients with severe hyponatraemia (pNa <120 mmol/L) in 2005, 2010 and 2015, and compared the recent mortality rate with that of patients with pNa 120-125 mmol/L. Results: Between 2005 and 2010 there was a doubling in the rate of specialist referral (32 to 68%, P = 0.003) and an increase in the use of active management of hyponatraemia in patients with pNa <120 mmol/L (63 to 88%, P = 0.02), associated with a reduction in mortality from 51 to 15% (P < 0.001). The improved rates of intervention were maintained between 2010 and 2015, but there was no further reduction in mortality. When data from all three reviews were pooled, specialist consultation in patients with pNa <120 mmol/L was associated with a 91% reduction in mortality risk, RR 0.09 (95% CI: 0.03-0.26), P < 0.001. Log-rank testing on in-hospital survival in 2015 found no significant difference between patients with pNa <120 mmol/L and pNa 120-125 mmol/L (P = 0.56). Conclusion: Dedicated specialist input and active management of severe hyponatraemia are associated with a reduction in mortality, to rates comparable with moderate hyponatraemia.