Effects Of Nitrate Supplementation Research Articles

Effects of nitrate supplementation via beetroot juice on contracting rat skeletal muscle microvascular oxygen pressure dynamics

NO3− supplementation via beetroot juice (BR) augments exercising skeletal muscle blood flow subsequent to its reduction to NO2− then NO. We tested the hypothesis that enhanced vascular control following BR would elevate the skeletal muscle O2 delivery/O2 utilization ratio (microvascular PO2, PmvO2) and raise the PmvO2 during the rest-contractions transition. Rats were administered BR (~0.8mmol/kg/day, n=10) or water (control, n=10) for 5 days. PmvO2 was measured during 180s of electrically induced (1Hz) twitch spinotrapezius muscle contractions. There were no changes in resting or contracting steady-state PmvO2. However, BR slowed the PmvO2 fall following contractions onset such that time to reach 63% of the initial PmvO2 fall increased (MRT1; control: 16.8±1.9, BR: 24.4±2.7s, p<0.05) and there was a slower relative rate of PmvO2 fall (Δ1PmvO2/τ1; control: 1.9±0.3, BR: 1.2±0.2mmHg/s, p<0.05). Despite no significant changes in contracting steady state PmvO2, BR supplementation elevated the O2 driving pressure during the crucial rest-contractions transients thereby providing a potential mechanism by which BR supplementation may improve metabolic control.

Dietary nitrate dramatically increases force in mouse skeletal muscle

Nitrate supplementation has beneficial effects on exercise performance, with both improved mitochondrial efficiency and reduced ATP cost of muscle force production implicated. It was the purpose of this study to examine if nitrate supplementation could improve Ca2+ handling and contractile function using skeletal muscles from C57bl/6 male mice given 0.1 mmol • kg−1 sodium nitrate in drinking water for 7 days (Nitrate). Age matched controls were provided water without added nitrate (Control). Myoplasmic free [Ca2+] ([Ca2+]i) was significantly elevated from 20–150 Hz stimulation in fast‐twitch muscle fibers dissected from Nitrate (n = 5) compared to Control mice (n = 7). This resulted in increased contractile force at stimulation frequencies up to 50 Hz. At 100 Hz stimulation, the rate of force development was ~35% faster in the Nitrate group. These changes were accompanied by increased expression of the Ca2+ handling proteins calsequestrin and the dihydropyridine receptor in fast‐twitch muscles of Nitrate mice. In conclusion, these results show a striking and novel effect of nitrate supplementation on intracellular Ca2+ handling and force production. These data provide a new mechanism by which nitrate can exert effects on muscle performance, and provide a potential new therapeutic role for nitrate in conditions with muscle weakness.

The effect of nitrate supplementation on the biochemical composition of benthic diatoms and the growth and survival of post-larval abalone

Elevating the nitrogen concentration in microalgal growth media can elevate the protein content of the algae and consequently increase their dietary value to molluscs. This study examined the protein content, and dietary value to abalone post-larvae, of seven benthic diatoms acclimated to high-(“H” = 49.4 mg NO 3–N l − 1 ) and standard-nitrate (“S” = 16.5 mg NO 3–N l − 1 ) Walne medium. In Experiment 1, the level of nitrate in the culture medium did not significantly affect the protein content of Cocconeis sp., Cylindrotheca closterium or Nitzschia ovalis, and variation in the growth of post-larval Haliotis iris was not associated with nitrate level or the protein content of the diatoms. When the same six diatom diets were added daily as cell suspensions, growth and survival were much lower than for the equivalent strains fed as established films ( P < 0.0001). In Experiment 2a, the protein content of Navicula incerta was elevated by nitrate supplementation , and the high nitrate strain retained a higher protein content ( P = 0.005) even after 24 days growing in unenriched, flowing seawater. Haliotis rufescens post-larvae grew significantly faster when fed N. incerta H than when fed N. incerta S ( P = 0.006) and survival was also higher with this diet (67 versus 54%). In Experiment 2b, there was no significant effect of nitrate level on protein content of four diatoms or the performance of post-larval H. rufescens. There was, however, a strong positive correlation ( r = 0.95, P < 0.0001) between post-larval survival and the lipid content of the diatom diets. Post-larval growth showed positive, but marginally non-significant, relationships with diatom protein and carbohydrate, but no relationship with lipid content. Overall, only one of seven benthic diatom species acclimated to high-nitrate growth medium displayed significantly elevated protein content. Diatom protein content explained relatively little of the variation in food value of diatom strains for post-larval abalone but lipid content correlated strongly with post-larval survival.

Impact of rhizobial inoculation and nitrogen utilization in plant growth promotion of maize (Zea mays L.)

Abstract. Singh RK, Malik N, Singh S. 2013. Impact of rhizobial inoculation and nitrogen utilization in plant growth promotion of maize (Zea mays L.). Nusantara Bioscience 5: 8-14. During the course of growing population demands, there has been an increasing interest in exploring the possibility of extending the beneficial interaction between cereals and plant growth promoting rhizobacteria (PGPR). Endophytes are a group of microorganism that resides mostly in the intercellular space of various parts of plants including cereals. Assessment of plant growth promoting properties of the five-rhizobial strains belonging to α subclass i.e. Rhizobium leguminosarum bv. phaseoli RRE6 and R. undicola RRE36 and those belonging to β subclass i.e. Burkholderia cepacia (RRE3, RRE5, RRE25) was done by growing maize plants inoculated with these strains. Inoculated maize plants showed a significant increase in plant height, root length, shoot and root dry weight over uninoculated control. R. leguminosarum bv. phaseoli RRE6 and B. cepacia RRE5 among the α and β-subclass representatives respectively, gave the best inoculation response. Effect of nitrate supplementation upon maize-RRE6 and RRE5 association was also studied and a significant increase in all the growth parameters and colonization ability was recorded when nitrate was present as a supplement over uninoculated control and maize-RRE6 and RRE5 in absence of external nitrate.