Intracellular pH in lizards after hypercapnia

1995 ◽  
Vol 268 (4) ◽  
pp. R889-R895
Author(s):  
G. K. Snyder ◽  
J. R. Nestler ◽  
J. I. Shapiro ◽  
J. Huntley
Keyword(s):  
Skeletal Muscle ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Ion Transport ◽  
Intracellular Ph ◽  
Resonance Spectroscopy ◽  
Lizard Species ◽  
Dipsosaurus Dorsalis ◽  
Active Processes ◽  
Phi Regulation

We used the transmembrane distribution of 5,5-[2-14C]dimethyloxazolidine-2,4-dione ([14C]DMO) and 31P magnetic resonance spectroscopy (NMR) to investigate the effects of hypercapnia on intracellular pH (pHi) in brain and skeletal muscle of two lizard species: Anolis equestris and Dipsosaurus dorsalis. In control animals (normocapnic), plasma PCO2 (3.3 +/- 0.1 kPa) and plasma pH (7.52 +/- 0.01) for D. dorsalis were not significantly different from the values for A. equestris (2.8 +/- 0.2 kPa and 7.59 +/- 0.02, respectively). Furthermore 60 min of 5% CO2 increased plasma PCO2 and decreased plasma pH by the same amounts in both species. Brain pHi values determined with the DMO method were not significantly different from values determined with NMR. Control values of brain pHi (DMO, 7.16 +/- 0.01; NMR, 7.11 +/- 0.02) and muscle pHi were significantly higher for D. dorsalis (DMO, 7.15 +/- 0.03) than for A. equestris (DMO, 6.99 +/- 0.03; NMR, 7.02 +/- 0.02 for brain; DMO, 6.97 +/- 0.03 for muscle). In addition, changes in tissue pHi after 60 min of 5% CO2 were significantly different for the two species. In D. dorsalis muscle and brain pHi decreased significantly after hypercapnia, whereas in A. equestris muscle pHi decreased significantly but brain pHi was unchanged. Our findings were independent of the methods used to determine pHi. The smaller change in brain and muscle pHi than in plasma pH for A. equestris is consistent with the view that pHi regulation involves active processes such as transmembrane ion transport.(ABSTRACT TRUNCATED AT 250 WORDS)

Endurance-Trained and Untrained Skeletal Muscle Bioenergetics Observed With Magnetic Resonance Spectroscopy

1996 ◽  
Vol 21 (4) ◽  
pp. 251-263 ◽  
Author(s):  
Bart M. Guthrie ◽  
Simon P. Frostick ◽  
David J. Mikulis ◽  
K. Wayne Marshall ◽  
Jack Goodman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Intracellular Ph ◽  
Adenosine Triphosphate ◽  
Inorganic Phosphate ◽  
Isometric Exercise ◽  
Oxidative Capacity ◽  
Resonance Spectroscopy ◽  
Trained Subjects

Resting and submaximal isometric exercise 31P magnetic resonance spectroscopy (MRS) was carried out on 7 endurance-trained males (26.0 ± 3 yrs) and 7 sedentary males (27.0 ± 4 yrs). Spectral analysis provided peak areas of phosphocreatine (PCr), inorganic phosphate (Pi), adenosine triphosphate (ATP), and the chemical shift of Pi relative to PCr. The ratio of PCr/Pi was moderately lower during rest (preexercise p =.13, postexercise p =.18), and significantly higher during exercise (p < .05) in the trained subjects. Intracellular pH patterns were the same for both groups; a transient alkalosis was observed at the onset of exercise with a return to resting levels after 2 min. Differences suggest improved ATP resynthesis rate in the trained subjects during exercise. Intracellular pH changes can be attributed to the utilization of hydrogen ions that accompany PCr hydrolysis during work. The findings are congruent with previous reports indicating a superior oxidative capacity in trained skeletal muscle. Key words: 31P MRS, isometric exercise, phosphocreatine, inorganic phosphate, adenosine triphosphate, intracellular pH

scholarly journals A phosphorus-31 nuclear magnetic resonance investigation of intracellular environment in human normal and sickle cell blood

Blood ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 196-209 ◽  
Author(s):  
YF Lam ◽  
AK Lin ◽  
C Ho
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Intracellular Ph ◽  
Sickle Cell ◽  
Resonance Spectroscopy ◽  
Blood Samples ◽  
Intracellular Environment ◽  
Nuclear Magnetic

Abstract Intracellular pH and 2,3-diphosphoglycerate concentration in sickle cell amenia and normal human blood samples were measured by means of phosphorus-31 nuclear magnetic resonance spectroscopy. To monitor the concentrations of various internal phosphorylated metabolites of intact red blood cells, heparinized blood samples were used and were incubated at 37 degrees C with 5.6% C92, 25% O2, and 69.4% N2. The 31P chemical shifts of phosphorylated compounds, such as 2,3-diphosphoglycerate, adenosine 5′-triphosp-ate, and inorganic phosphate, depend on pH, and by using an appropriate calibration curve, the intracellular pH of intact erythrocytes can be obtained. The intracellular pH values in fresh sickl cell blood and normal blood were found to be 7.14 and 7.29, respectively. However, the whole-blood pH, as measured by a standard pH meter, was found to be 7.54 for both types of blood. The initial concentration of 2,3-diphosphoglycerate in sickle cell blood was about 30% higher, but it was depleted much faster during incubation than that in normal blood. The difference in intracellular pH between these two types of blood samples remained constant during incubation, even after depletion of 2,3-diphosphoglycerate. These results suggest that there are differences in intracellular environment between normal and sickle cell blood. Thus, 31P nuclear magnetic resonance spectroscopy provides a fast, direct, continuous, and noninvasive way to monitor the intracellular environment of intact erythrocytes.

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