Extracellular metabolisation of NADH by blood cells correlates with intracellular ATP levels.

A new assay allowing quantitation of extracellular NADH metabolisation by intact blood cells was compared with the intracellular ATP/ADP ratio of these cells. The sensitivity, reproducibility and NADH specificity of this assay were determined. The diagnostic potential of this test was examined in a study with highly conditioned athletes. NADH consumption was measured before and immediately after maximum aerobic performance as well as 1 day later and was compared with the ATP/ADP level in these blood cells. A significant decline of cellular energy after aerobic performance was detected with both approaches to a similar extent (P<0.01). However, the extracellular NADH metabolisation assay (ENMA) is more convenient to perform than the determination of intracellular ATP/ADP. Due to its easy and versatile handling, a huge array of possible applications like monitoring the training efficiency of athletes, the fitness of senior citizens or the recovery from disease may be envisioned.

NADH supplementation decreases pinacidil-primed I K ATP in ventricular cardiomyocytes by increasing intracellular ATP.

1 The aim of this study was to investigate the effect of nicotinamide-adenine dinucleotide (NADH) supplementation on the metabolic condition of isolated guinea-pig ventricular cardiomyocytes. The pinacidil-primed ATP-dependent potassium current I(K(ATP)) was used as an indicator of subsarcolemmal ATP concentration and intracellular adenine nucleotide contents were measured. 2 Membrane currents were studied using the patch-clamp technique in the whole-cell recording mode at 36-37 degrees C. Adenine nucleotides were determined by HPLC. 3 Under physiological conditions (4.3 mM ATP in the pipette solution, ATP(i)) I(K(ATP)) did not contribute to basal electrical activity. 4 The ATP-dependent potassium (K((ATP))) channel opener pinacidil activated I(K(ATP)) dependent on [ATP](i) showing a significantly more pronounced activation at lower (1 mM) [ATP](i). 5 Supplementation of cardiomyocytes with 300 micro g ml(-1) NADH (4-6 h) resulted in a significantly reduced I(K(ATP)) activation by pinacidil compared to control cells. The current density was 13.8+/-3.78 (n=6) versus 28.9+/-3.38 pA pF(-1) (n=19; P<0.05). 6 Equimolar amounts of the related compounds nicotinamide and NAD(+) did not achieve a similar effect like NADH. 7 Measurement of adenine nucleotides by HPLC revealed a significant increase in intracellular ATP (NADH supplementation: 45.6+/-1.88 nmol mg(-1) protein versus control: 35.4+/-2.57 nmol mg(-1) protein, P<0.000005). 8 These data show that supplementation of guinea-pig ventricular cardiomyocytes with NADH results in a decreased activation of I(K(ATP)) by pinacidil compared to control myocytes, indicating a higher subsarcolemmal ATP concentration. 9 Analysis of intracellular adenine nucleotides by HPLC confirmed the significant increase in ATP.

Genetic diversity in European red deer (Cervus elaphus L.): anthropogenic influences on natural populations.

Allozyme, microsatellite and mtDNA (RFLP and sequence) data of European red deer populations were examined as to their capability of indicating anthropogenic influences such as the keeping of animals in enclosures, selective hunting for trophies translocation of specimens to improve trophy quality and habitat fragmentation. Deer in enclosures revealed considerable deviations of allele frequencies from isolation-by-distance expectations but no remarkable loss of genetic diversity. Particular allozyme genotypes were associated with antler morphology, and selective hunting was shown to alter allele frequencies in the expected direction. Habitat fragmentation is reflected by various kinds of genetic markers but due to the lack of information on population histories no unequivocal evidence on particular human activities could be obtained.

On the safety of reduced nicotinamide adenine dinucleotide (NADH).

The objective of the study was to determine both the toxicity of the stabilized orally absorbable form of nicotinamide adenine dinucleotide (NADH) (ENADA) and the maximum tolerated intravenous dose (MTD) of betaNADH (the reduced form of NADH) in beagle dogs. The administration of the stabilized orally absorbable form of NADH to beagle dogs at dose levels of 20, 100, and 150 mg/kg for 14 days elicited no signs of a toxicological effect. A transitory change in stool formation was observed with the intermediate and high dose in males. There were also apparent increases in adrenal, heart, kidney, liver, brain, and thyroid weights, particularly in males, but none of these changes were considered to be toxicologically significant. In addition, four dogs (two of each sex) received intravenous infusions of 100 mg NADH/kg/day for 4 days, followed by 200 mg NADH/kg/day for 3 days, followed by 500 mg NADH/kg/day for 4 days, and 1000 mg NADH/kg/day on the final day. At the end of the MTD phase, the control animals that had received saline solution in the MTD phase were used to evaluate the potential toxicity of the established MTD. These animals received 500 mg NADH/kg/day for 14 days (fixed dose phase). There were no deaths. At dose levels between 100 and 1000 mg/kg/day, effects on the cardiovascular system and also some evidence of an effect on the central nervous system and on the adrenals were observed. At doses of 500 mg/kg/day and above, food consumption and body weight were reduced. On the basis of the observed changes, the maximum intravenous dose of NADH tolerated by beagle dogs was considered to be 500 mg/kg/day. There were no gross histological findings indicative of toxicity in the organs of tissues examined. Based on these findings, the stabilized orally absorbable form of NADH (ENADA) can be regarded as safe.

Oxidative stress: potential of distinct peroxide determination systems.

When reactive oxygen species attack biological structures, peroxides, which are short-lived oxidative intermediates, are generated. We evaluated the potential of two different, commercially available peroxide activity assays (Pox-Act and d-ROMS) to see whether the results were associated with the clinical condition of subjects who were participating in a routine health care program. Furthermore, we determined the total antioxidant status (TAS) and the titer of autoantibodies against oxidized low-density lipoprotein (oLAb) to verify the hydroperoxide measurements. Subjects with medical conditions (hereafter referred to as patients) had significantly increased serum peroxide levels compared to healthy subjects. The d-ROMS kit indicated that 86% of subjects had an increased level of total peroxides. Although the assays had a significant correlation (p<0.001), 34% of the subjects had an increased total peroxide concentration in the Pox-Act assay that was clearly associated with clinical symptoms. Furthermore, the sensitivity of the Pox-Act assay was 35 times higher than that of the d-ROMS kit. In subjects with medical conditions, there was a trend toward a decreased TAS and a slightly increased oLAb titer in comparison to healthy subjects, but this was not statistically significant. The Pox-Act assay seems to be a valuable tool for the determination of total peroxides, while the results from the d-ROMS kit should be considered with caution.