Darin Van Gammeren

Apocynin attenuates diaphragm oxidative stress and protease activation during prolonged mechanical ventilation

Objective: To investigate whether apocynin protects the diaphragm from wasting and oxidative stress during mechanical ventilation (MV). Design: Prospective, randomized, controlled study. Setting: Research laboratory. Subjects: Adult female Sprague-Dawley rats. Interventions: Rats were randomly assigned to one of five experimental groups: 1) acutely anesthetized control, 2) spontaneous breathing control, 3) spontaneously breathing control with administration of the nicotinamide adenine dinucleotide phosphate oxidase inhibitor, apocynin, 4) mechanically ventilated, and 5) mechanically ventilated with apocynin. Measurements and Main Results: Apocynin attenuated MV-induced diaphragmatic oxidative stress, contractile dysfunction, and type I, type IIa, and type IIb/IIx myofiber atrophy. The apocynin-induced attenuation of MV-induced diaphragmatic atrophy and contractile dysfunction occurred in conjunction with a reduction in the small increase in nicotinamide adenine dinucleotide phosphate oxidase activity as well as the preservation of total glutathione levels, glutathione peroxidase protein abundance, and a decrease in the activation of the cysteine proteases, calpain-1 and caspase-3. Interestingly, independent of MV, apocynin increased diaphragmatic levels of calpastatin, an endogenous calpain inhibitor. Furthermore, treatment of skeletal muscle cells in culture (C2C12 myotubes) with apocynin resulted in an increase in both calpastatin mRNA levels and protein abundance. Conclusions: Our results suggest that the protective effects of apocynin on the diaphragm during prolonged MV seem to be linked to both its functions as an antioxidant and role in cellular signaling regulating the cysteine protease inhibitor calpastatin.

Effects of norandrostenedione and norandrostenediol in resistance-trained men.

The purpose of this study was to determine the effects of norsteroid supplementation (224 mg of 19-nor-4-androstene-3,17-dione and 120 mg of 19-nor-4-androstene-3,17-diol, total daily dose = 344 mg) on body composition and strength in resistance-trained men. In a placebo-controlled, double-blind, randomized fashion, 10 subjects received the norsteroid (11 capsules containing a combination of both norsteroids) or a placebo for 8 wk (five subjects per group). Each subject participated in resistance training an average of 4 d/wk for the duration of the study. Body composition was determined via dual-energy x-ray absorptiometry. Strength was determined using a one-repetition maximum bench press and a one-repetition maximum biceps curl. With regard to all measures in both groups, there were no significant changes between before and after the study.Therefore, in this small sample of resistance-trained men, 344 mg/d of norsteroid supplementation had no effect on strength or body composition.

The effects of four weeks of ribose supplementation on body composition and exercise performance in healthy, young, male recreational bodybuilders: a double-blind, placebo-controlled trial.

Abstract Background: Ribose is a pentose sugar that is present in ribonucleic acids, riboflavin, nucleotides, and adenosine triphosphate. Whether exogenous ribose administration affects skeletal muscle concentrations of total adenine nucleotides is unknown. Whether supplementation with ribose positively affects body composition or exercise performance in recreational bodybuilders also is unknown. Objective: The purpose of this double-blind, placebo-controlled trial was to determine the effects of 4 weeks of ribose supplementation on body composition and exercise performance in healthy, young, male recreational bodybuilders. Methods: Healthy, male recreational bodybuilders aged 18 to 35 years were recruited and randomized to a ribose-supplemented group (10 g/d in powder formulation) or a placebo group (dextrose). Each subject participated in a heavy-resistance training program designed to increase skeletal muscle mass. Body composition (ie, body weight, body fat, lean body mass, fat mass, and bone mineral content) was assessed using dual-energy x-ray absorptiometry analysis. Muscular strength (as measured by a 1-repetition maximum-strength [1-RM] bench press) and total work performed (as measured by total repetitions for 10 sets of bench presses before muscular failure; 1-minute resting interval between sets) to muscular failure at a submaximal load (100% of pretest body weight) were ascertained. In addition, 24-hour dietary recalls were obtained before and after the study. Results: Twenty men (mean age ± SE, 23.9 ± 1.4 years) were enrolled; 19 subjects completed 24-hour dietary recalls and exercise performance testing; 12 subjects completed the study (24-hour dietary recalls, exercise performance, and body composition). No baseline differences were found between the 2 groups for any of the measured parameters. The ribose-supplemented group experienced a significant pretreatment-to-posttreatment increase in the total work performed, whereas the placebo group did not change significantly (24.5 ± 7.6 to 29.3 ± 7.5 repetitions; 19.6% ribose [ P = 0.028] vs 34.1 ± 8.6 to 38.2 ± 8.0 repetitions, 12.0% placebo). In addition, the ribose-supplemented group experienced a significant increase in 1-RM bench press strength, whereas the placebo group did not change significantly (114.1 ± 13.6 to 117.7 ± 14.0 kg, 3.2% ribose [ P = 0.008] vs 129.6 ± 14.2 to 131.8 ± 14.5 kg, 1.7% placebo). No pretreatment-to-posttreatment within-group or between-group differences were found for any of the measures of body composition or the 24-hour dietary data. Conclusion: The results of this study indicate that supplementation with ribose 10 g/d for 4 weeks resulted in significant increases in muscular strength and total work performed in recreational bodybuilders in this study, although no significant changes in body composition or 24-hour dietary data were found.