Strenuous Acute Exercise Induces Slow and Fast Twitch-Dependent NADPH Oxidase Expression in Rat Skeletal Muscle.

The enzymatic complex Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (NOx) may be the principal source of reactive oxygen species (ROS). The NOX2 and NOX4 isoforms are tissue-dependent and are differentially expressed in slow-twitch fibers (type I fibers) and fast-twitch fibers (type II fibers) of skeletal muscle, making them different markers of ROS metabolism induced by physical exercise. The aim of this study was to investigate NOx signaling, as a non-adaptive and non-cumulative response, in the predominant fiber types of rat skeletal muscles 24 h after one strenuous treadmill exercise session. The levels of mRNA, reduced glycogen, thiol content, NOx, superoxide dismutase, catalase, glutathione peroxidase activity, and PPARGC1α and SLC2A4 gene expression were measured in the white gastrocnemius (WG) portion, the red gastrocnemius (RG) portion, and the soleus muscle (SOL). NOx activity showed higher values in the SOL muscle compared to the RG and WG portions. The same was true of the NOX2 and NOX4 mRNA levels, antioxidant enzymatic activities, glycogen content. Twenty-four hours after the strenuous exercise session, NOx expression increased in slow-twitch oxidative fibers. The acute strenuous exercise condition showed an attenuation of oxidative stress and an upregulation of antioxidant activity through PPARGC1α gene activity, antioxidant defense adaptations, and differential gene expression according to the predominant fiber type. The most prominent location of detoxification (indicated by NOX4 activation) in the slow-twitch oxidative SOL muscle was the mitochondria, while the fast-twitch oxidative RG portion showed a more cytosolic location. Glycolytic metabolism in the WG portion suggested possible NOX2/NOX4 non-regulation, indicating other possible ROS regulation pathways.

High-dose Nandrolone Decanoate induces oxidative stress and inflammation in retroperitoneal adipose tissue of male rats.

The non-therapeutic use of the androgenic anabolic steroid Nandrolone Decanoate is popular due to its effects on physical performance and body composition, especially for its lipolytic and anabolic effects associated. However, high doses of such drugs are often associated with a series of pathologies related to unbalanced redox homeostasis, which, in turn, can be linked to inflammation. The oxidative stress onset could deregulate the secretion of cytokines, evidencing a dysfunctional adipocyte. Thus, the aim of this study was to investigate the effect of supraphysiological doses of Nandrolone Decanoate on redox homeostasis of retroperitoneal fatpad of male rats and its relationship with cytokines-based inflammatory signaling. Hydrogen peroxide production was assessed in the retroperitoneal fat pad of adult male rats which received either 10 mg kg of Nandrolone Decanoate or only a vehicle. Also, catalase, superoxide dismutase and glutathione peroxidase activities were measured, together with total reduced thiols and protein carbonylation, as well as IL-1ß, TNF-α, and IL-6 local levels. High doses of Nandrolone Decanoate caused an increase in the hydrogen peroxide production, together with lower activities of the antioxidant enzymes and lower levels of total reduced thiol. There were also higher protein carbonylation and greater levels of IL-1ß, TNF-α, and IL-6 in the treated group compared to control group. Therefore, it was possible to verify that high doses of Nandrolone Decanoate cause oxidative stress and induce higher inflammatory signaling in retroperitoneal fat pad of male rats.

Phytomodulatory proteins promote inhibition of hepatic glucose production and favor glycemic control via the AMPK pathway.

Phytomodulatory proteins from the latex of the medicinal plant Calotropis procera has been shown to be implicated in many pharmacological properties. However there is no current information about their activity on glucose metabolism, although the latex is used in folk medicine for treating diabetes. In this study the phytomodulatory proteins (LP) from C. procera latex were assessed on glycemic homeostasis. Control animals received a single intravenous dose (5 mg/kg) of LP or saline solution (CTL). Four hours after treatment, the animals were euthanized and their livers were excised for analysis by western blot and RT-PCR AMP-activated protein kinase (AMPK), phosphoenolpyruvate carboxykinase (PEPCK) and tumor necrosis factor alpha (TNF-α). In vivo tests of intraperitoneal tolerance to insulin, glucose and pyruvate were also performed, and the effect of LP administration on fed glycemia was studied followed by blood analysis to determine serum insulin levels. Treatment with LP reduced glycemia two hours after glucose administration (LP: 87.2 ± 3.70 mg/dL versus CTL: 115.6 ± 8.73 mg/dL). However, there was no change in insulin secretion (CTL: 14.16 ± 0.68 mUI/mL and LP: 14.96 ± 0.55 mUI/mL). LP improved the insulin sensitivity, represented by a superior glucose decay constant during an insulin tolerance test (kITT) (4.17 ± 0.94%/min) compared to the CTL group (0.82 ± 0.72%/min), and also improved glucose tolerance at 30 min (105.2 ± 12.4 mg/dL versus 154.2 ± 18.51 mg/dL), while it decreased hepatic glucose production at 15 and 30 min (LP: 75.5 ± 9.31 and 52.5 ± 12.05 mg/dL compared to the CTL: 79.0 ± 3.02 and 84.5 ± 7.49 mg/dL). Furthermore, there was a significant inhibition of gene expression of PEPCK (LP: 0.66 ± 0.06 UA and CTL: 1.14 ± 0.22 UA) and an increase of phosphorylated AMPK (LP: 1.342 ± 0.21 UA versus CTL: 0.402 ± 0.09 UA). These findings confirm the effect of LP on glycemic control and suggest LP may be useful in diabetes treatment. However, the pharmacological mechanism of LP in PEPCK modulation still needs more clarification.