Low-intensity tensile loading increases intratendinous glucose uptake in the Achilles tendon.

The metabolic activity of tendinous tissues has traditionally been considered to be of limited magnitude. However, recent studies have suggested that glucose uptake increases in the force-transmitting tissues as a response to contractile loading, which in turn indicates an elevated tissue metabolism. The purpose of the present study was to investigate whether such a mechanism could be observed for the human Achilles tendon following tensile loading. Six subjects participated in the study. Unilateral Achilles tendon loading was applied by 25-min intermittent voluntary plantar flexor contractions. A radioactive tracer ([18F]-2-fluoro-2-deoxy-D-glucose) was administered during muscle action, and glucose uptake was measured by use of PET. Regions of interest were defined on the PET images corresponding to the cross section of Achilles tendon at two longitudinally separated sites (insertion and free tendon). Glucose uptake index was determined within respective regions of interest for the active and resting leg. Tendon force during voluntary contractions was approximately 13% of maximal voluntary contraction force. Tendon loading induced an elevated glucose uptake index compared with that of the contralateral resting tendon in the region of tendon insertion (0.13 +/- 0.05 vs. 0.09 +/- 0.02; P < 0.05) and at the free tendon (0.12 +/- 0.01 vs. 0.08 +/- 0.02; P < 0.05). The present data suggest that tissue metabolism is elevated in the human Achilles tendon in response to low-intensity loading.     

Enhanced mitochondrial sensitivity to creatine in rats bred for high aerobic capacity.

Qualitative and quantitative measures of mitochondrial function were performed in rats selectively bred 15 generations for intrinsic aerobic high running capacity (HCR; n = 8) or low running capacity (LCR; n=8). As estimated from a speed-ramped treadmill exercise test to exhaustion (15 degrees slope; initial velocity of 10 m/min, increased 1 m/min every 2 min), HCR rats ran 10 times further (2,375+/-80 m) compared with LCR rats (238+/-12 m). Fiber bundles were obtained from the soleus and chemically permeabilized. Respiration was measured 1) in the absence of ADP, 2) in the presence of a submaximally stimulating concentration of ADP (0.1 mM ADP, with and without 20 mM creatine), and 3) in the presence of a maximally stimulating concentration of ADP (2 mM). Although non-ADP-stimulated and maximally ADP-stimulated rates of respiration were 13% higher in HCR compared with LCR, the difference was not statistically significant (P>0.05). Despite a similar rate of respiration in the presence of 0.1 mM ADP, HCR rats demonstrated a higher rate of respiration in the presence of 0.1 mM ADP+20 mM creatine (HCR 33% higher vs. LCR, P<0.05). Thus mitochondria from HCR rats exhibit enhanced mitochondrial sensitivity to creatine (i.e., the ability of creatine to decrease the Km for ADP). We propose that increased respiratory sensitivity to ADP in the presence of creatine can effectively increase muscle sensitivity to ADP during exercise (when creatine is increased) and may be, in part, a contributing factor for the increased running capacity in HCR rats.     

Genotoxicity Evaluation of Pectin-Mediated Gold Nanoparticles on Zebrafish Embryos (Danio rerio)

Applied Biochemistry and Microbiology - Pectin is a polymer commonly found in the fruit peels. Pectin-mediated gold nanoparticles (AuNPs) were fabricated and characterized by spectroscopic and...     

Immobilization of a Mixed Culture of Oxygenic Phototrophic Microorganisms on a Chitosan-Based Sorbent for Nutrient Bioremoval

Applied Biochemistry and Microbiology - The immobilization of cells of a mixed culture of the microalgae (MA) Micractinium sp. NAMSU A-19 and cyanobacteria (CB) Synechococcus sp. 1Dp66E-1 on a...     

Antifungal Surfaces

Applied Biochemistry and Microbiology - This review presents recent data about various types of antifungal surfaces (nanostructured, functionalized, and with modified wettability) used in medicine,...     

Plant Stress and Allelotoxicity of Soils

Doklady Biological Sciences - Stress exposures during vegetation are known to reduce the yield in crops, but the intensity and duration of stress is rather difficult to determine from the crop...     

A Correlation of Excitatory and Inhibitory Synaptic Processes in the Antinociceptive Raphe Magnus Nucleus in a Hydrocortisone-Protected Model of Parkinson’s Disease

Journal of Evolutionary Biochemistry and Physiology - In neurodegenerative diseases, mainly in Parkinson’s disease (PD), neurodegeneration involves antinociceptive centers, which is...     

The Motor Synergies’ Organization Features at Different Levels of Motor Control during High Coordinated Human’s Movement

Journal of Evolutionary Biochemistry and Physiology - The study considers the synergetic effects manifested at the level of interaction between the various parts of the musculoskeletal system with...     

Morphofunctional Features of Two Types of Phagocytes in the Holothurian Еupentacta fraudatrix (Djakonov et Baranova, 1958)

Journal of Evolutionary Biochemistry and Physiology - Phagocytes of the Far Eastern holothurian Eupentacta fraudatrix are separated by gradient centrifugation into two fractions (P1 and P2...