Inorganic Phosphate

Non‐invasive determination of mitochondrial content is an important objective in clinical and sports medicine. 31P MRS approaches to obtain information on this parameter at low field strength typically require in‐magnet exercise. Direct observation of the intra‐mitochondrial inorganic phosphate (Pi) pool in resting muscle would constitute an alternative, simpler method. In this study, we exploited the higher spectral resolution and signal‐to‐noise at 7T to investigate the MR visibility of this metabolite pool. 31P in vivo MR spectra of the resting soleus (SOL) muscle were obtained with 1H MR image‐guided surface coil localization (six volunteers) and of the SOL and tibialis anterior (TA) muscle using 2D CSI (five volunteers). A resonance at a frequency 0.38 ppm downfield from the cytosolic Pi resonance (Pi1; pH 7.0 ± 0.04) was reproducibly detected in the SOL muscle in all subjects and conditionally attributed to the intra‐mitochondrial Pi pool (Pi2; pH 7.3 ± 0.07). In the SOL muscl...

Non‐invasive determination of mitochondrial content is an important objective in clinical and sports medicine. 31P MRS approaches to obtain information on this parameter at low field strength typically require in‐magnet exercise. Direct observation of the intra‐mitochondrial inorganic phosphate (Pi) pool in resting muscle would constitute an alternative, simpler method. In this study, we exploited the higher spectral resolution and signal‐to‐noise at 7T to investigate the MR visibility of this metabolite pool. 31P in vivo MR spectra of the resting soleus (SOL) muscle were obtained with 1H MR image‐guided surface coil localization (six volunteers) and of the SOL and tibialis anterior (TA) muscle using 2D CSI (five volunteers). A resonance at a frequency 0.38 ppm downfield from the cytosolic Pi resonance (Pi1; pH 7.0 ± 0.04) was reproducibly detected in the SOL muscle in all subjects and conditionally attributed to the intra‐mitochondrial Pi pool (Pi2; pH 7.3 ± 0.07). In the SOL muscl...

Cellular metabolism depends on the appropriate concentration of intracellular inorganic phosphate (Pi). Pi starvation-responsive genes appear to be involved in multiple metabolic pathways, implying a complex Pi regulation system in microorganisms and plants. A group of enzymes is required for absorption and maintenance of adequate phosphate levels, which is released from phosphate esters and anhydrides. The phosphatase system is particularly suited for the study of regulatory mechanisms because phosphatase activity is easily measured using specific methods and the difference between the repressed and derepressed levels of phosphatase activity is easily detected. This paper analyzes the protein phosphatase system induced during phosphate starvation in different organisms.

Experiments were designed to evaluate the relative contribution of impulse propagation failure, high‐energy phosphate depletion, lowered pH, and impaired excitation‐contraction coupling to human muscle fatigue and recovery. 31P nuclear magnetic resonance spectroscopy measurements were made on adductor pollicis muscle, together with simultaneous measurements of M‐wave, force, and rectified integrated EMG (RIEMG). During fatigue, maximum voluntary contraction force (MVC) fell by 90%, pH fell from 7.1 to 6.4, and phosphocreatine was almost totally depleted. Neuromuscular efficiency (NME = force/RIEMG) was reduced to 40% of control at the end of the fatiguing contraction, and the M wave was reduced in amplitude and prolonged in duration. Following exercise, the M wave returned to normal within 4 minutes. pH, high‐energy phosphates, and MVC recovered within 20 minutes. By contrast, neuromuscular efficiency did not recover within 60 minutes. These findings indicate three different compone...

The sequencing and availability of inorganic and organic fractions of phosphorus at different days interval in two soils after the fertilizer (SSP) application was the objective of this investigation. The study helped to obtain the sequence of dominating pool of phosphorus at different days intervals and the rate of release in the soil. This sequential fractionation was used for two native soils i) Alluvial soil and ii) Acidic soil, with 0 to 80 ppm SSP/ 100 gm soil added in a pot experiment and the soil samples were analyzed at different days intervals started from 5 days to 60 days. The result revealed that amount of maximum total P fell in the range from 325.14 to 387.30 mg kg-1 and 284.60 to 330.25 mg kg-1 for alluvial soil and acid soil, respectively up to 30 days. In case of inorganic P fractions under alluvial soil the dominating species were like Ca-P > Fe-P > Al-P >Saloid-P, while under acidic soil the following order Fe-P > Al-P > Ca-P > Saloid-P was obse...

The sequencing and availability of inorganic and organic fractions of phosphorus at different days interval in two soils after the fertilizer (SSP) application was the objective of this investigation. The study helped to obtain the sequence of dominating pool of phosphorus at different days intervals and the rate of release in the soil. This sequential fractionation was used for two native soils i) Alluvial soil and ii) Acidic soil, with 0 to 80 ppm SSP/ 100 gm soil added in a pot experiment and the soil samples were analyzed at different days intervals started from 5 days to 60 days. The result revealed that amount of maximum total P fell in the range from 325.14 to 387.30 mg kg-1 and 284.60 to 330.25 mg kg-1 for alluvial soil and acid soil, respectively up to 30 days. In case of inorganic P fractions under alluvial soil the dominating species were like Ca-P > Fe-P > Al-P >Saloid-P, while under acidic soil the following order Fe-P > Al-P > Ca-P > Saloid-P was obse...

Sprint Interval Training (SIT) includes high intensity intermittent forms of cycling or running repeated sprints loads. Fatigue can be defined as impairment in muscle performance. Neuromuscular and-or ionic perturbation during fatigue have investigated before. The aim of this study was to investigate the effects of SIT on sprint performance, ionic regulation and levels of creatine kinase (CK) and lactate dehydrogenase (LDH) during exhaustive exercise in young men. Fourteen male (22.3± 3.1 year) participated the study voluntarily. Before the training program, maximal 30 m sprint time and maximum voluntary contraction force (MVC) were measured. The subjects perform the exhaustion cycle test before and after the SIT. Earlobe capillary blood lactate concentration was measured just before and after the exhaustion test. The blood serum potassium (K), inorganic phosphate (Pi), CK and LDH were measured just before and immediately after the exhaustion test from the antecubital vein. After th...

The carp ponds of Deroua station (Beni Mellal, Centre of Morocco) receive a large quantity of fertilizers, particularly urea and triple super phosphate during the entire period of culture. Only a small part of that is necessary to promote an adequate development of phytoplankton, the base of the food chain. A large part of the phosphate added to the ponds

The mechanisms responsible for the inhibition of shortening velocity that occurs during muscle fatigue have not been completely elucidated. Phosphorylation of the myosin regulatory light chain (RLC) occurs during heavy use; however, previous reports on its role in affecting velocity have been equivocal. To further understand the process of fatigue, we varied the levels of myosin RLC phosphorylation (from 10 to >50%) and the concentrations of protons (from pH 7 to 6.2) and phosphate (from 5 to 30 mM), all of which change during fatigue. We measured the mechanics of permeable rabbit psoas fibers at a temperature closer to physiological (30°C), using a temperature jump protocol to briefly activate the fibers at the higher temperature to preserve sarcomere homogeneity. Although lowered pH alone had an effect on velocity, it was the three factors together, i.e., high phosphorylation, low pH, and high phosphate, that acted synergistically to inhibit fiber velocity by ∼40%. Our data dem...

Background: Decrease in bone mass in JIA patients is multifactorial. By assessing the level of vitamin D and other associated parameters we can identify the deficiency earlier and can predict the risk of osteoporotic bone fracture & give appropriate supplements. Objective: To determine the status of serum 25(OH)D, calcium, inorganic phosphate, alkaline phosphatase and parathormone in patients with JIA. Materials and methods: It was a cross sectional study. Thirty newly diagnosed cases of JIA attending the pediatric rheumatology clinic of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from October 2015 to September 2016 were included. Thirty age and sex matched control were also selected. Serum 25(OH)D, calcium, inorganic phosphate, alkaline phosphatase & parathormone were assesed in both cases and controls. Results: Hypovitaminosis D was present in 60% of JIA and 33% of controls. In JIA group the mean level of all biochemical parameters were significantly lower than cont...

Background Both dietary and serum levels of inorganic phosphate (Pi) have been linked to development of cancer in experimental studies. This is the first population-based study investigating the relation between serum Pi and risk of cancer in humans. Methods From the Swedish Apolipoprotein Mortality Risk (AMORIS) study, we selected all participants (> 20 years old) with baseline measurements of serum Pi, calcium, alkaline phosphatase, glucose, and creatinine (n = 397,292). Multivariable Cox proportional hazards regression analyses were used to assess serum Pi in relation to overall cancer risk. Similar analyses were performed for specific cancer sites. Results We found a higher overall cancer risk with increasing Pi levels in men ( HR: 1.02 (95% CI: 1.00-1.04) for every SD increase in Pi), and a negative association in women (HR: 0.97 (95% CI: 0.96-0.99) for every SD increase in Pi). Further analyses for specific cancer sites showed a positive link between Pi quartiles and the ri...