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F H SHAW

Publications and source records attributed to F H SHAW.

At least 19 recordsLinked to original sources
PubMed1959

The dimensions of the extracellular space in sartorius muscle.

A survey has been made of the amount of muscle water available to inulin, sucrose, and radioiodinated human serum albumin (RISA). The percentage spaces available to the three molecules are of the same order of magnitude, but the sucrose space > inulin space > albumin space. The kinetics of influx and efflux of RISA have been studied, and it appears that a small part of the albumin may be adsorbed in the extracellular phase. Nevertheless the albumin space would appear to give the best index of the extracellular volume. The scatter in values found for the extracellular space by all methods is very great, ranging from 8 to 40 per cent and renders invalid the use of a mean value for the calculation of intracellular concentrations. The variation within paired muscles is less than between pairs, provided the tissue has undergone no volume change. Increase in total muscle volume when the muscle is placed in a hypotonic solution leads to a decrease in the size of the extracellular space.

Electrolytes↗
PubMed1959

Muscle: a three phase system. The partition of monovalent ions across the cell membrane.

The partition of Li(+), Br(-), and I(-) across the membrane of the sartorius muscle of the toad Bufo marinus has been investigated both at the steady state and with kinetic methods. Li(+) was found to have access to an amount of muscle water similar to that of Na(+). Br(-) and I(-) could be regarded as being interchangeable with cellular Cl(-). None of the foreign ions caused significant losses of cellular K(+). Li(+) efflux from the cell was slower in muscles which were equilibrated for long periods in Li(+) than in short equilibrated muscles. Na(+) efflux from Li(+)-treated muscles was similar in rate to normal controls, but the amount of Na(+) in the slow fraction was increased by Li(+). I(-) efflux was extremely rapid, and it was not possible to differentiate kinetically between intra- and extracellular material. These results have been found to be consistent with the hypothesis of a three phase system for muscle.

Bromides↗
PubMed1959

Muscle: a three phase system. The partition of divalent ions across the membrane.

The partition of sulfate, Ca(++), and Mg(++) across the membrane of the sartorius muscle has been studied, and the effect of various concentrations of these ions in the Ringer solution on the cellular level of Na(+), K(+), and Cl(-) has been determined. The level of the three divalent ions in toad plasma and muscle in vivo has been assayed. Muscle was found to contain an almost undetectable amount of inorganic sulfate. Increases in the external level of these ions brought about increases in intracellular content, calculated from the found extracellular space as determined with radioiodinated serum albumin or inulin. Less of the cell water is available to sulfate than to Cl(-), and the Mg(++) space is less than the Na(+) space. An amount of muscle water similar to that found for Li(+) and I(-) appears to be available to these divalent ions. Sulfate efflux from the cell was extremely rapid, and it was not found possible to differentiate kinetically between intra- and extracellular material. These results are consistent with the theory of a three phase system, assuming the muscle to consist of an extracellular phase and two intracellular phases. Mg(++) and Ca(++) are adsorbed onto the ordered phase, and increments in cellular content found on raising the external level are assumed to occur in the free intracellular phase.

Calcium↗
PubMed1958

The distribution of inorganic phosphate in amphibian muscle.

The Na(+), K(+), and inorganic phosphate levels of the plasma and sartorius muscle of the toad Bufo marinus were determined. Soaking in normal Ringer brought about the usual cation shifts, but did not alter the level of inorganic phosphate in the cell. Increases in the external phosphate level brought about an increase in the internal phosphate, but the apparent phosphate space of muscle is somewhat smaller than the apparent Cl(-) space. Phosphate spaces were compared with inulin spaces and were found to be significantly greater. Alteration of the H(+) concentration of the high phosphate Ringer did not alter the partition of phosphate across the cell membrane. These results have been found to be consistent with the theory of a three compartment system for muscle, wherein the tissue is assumed to consist of an extracellular phase, and two intracellular phases. The inorganic phosphate of the cell is assumed to be adsorbed onto the "ordered phase," and increments in organic phosphate found on raising the external level are assumed to take place in the "free intracellular phase."

Amphibians↗