Beiträge zur allgemeinen Muskel- und Nervenphysiologie

Overton, Edward B.

doi:10.1007/bf01659816

Cited by 269 publications

(70 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3 practically no twitch tension could be detected at external Na+ concentrations below 40 mm, at least for the experimental conditions used here. This result is at variance with those of Overton (1902), Edwards, Ritchie & Wilkie (1956), Mashima & Matsumura (1962), Grabowski, Lobsiger & Littgau (1972), and Vaughan, Howell & Eisenberg (1972), whose experiments indicate that at [Na+]. = 40 ml the twitch tension is still practically normal.…”

Section: Methodssupporting

confidence: 72%

Inward movement of sodium ions in resting and stimulated frog's sartorius muscle

Venosa¹

1974

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. Paired frog sartorius muscles were exposed to Ringer solutions labelled with 22Na+ for about 20 min. At the end of this exposure one of them was stimulated supramaximally one hundred to two hundred times. Immediately after the stimulation both members of the pair were washed in a series of tubes filled with a Na+-free medium containing 3 x 10-5 M strophanthidin.2. Under the above conditions the intracellular component of the efflux was exponential with an average time constant (r) of 388 min, that is, approximately four times longer than in the presence of normal Ringer. On the other hand the mean r for the washout of the interfibre space was 3-2 min. 3. From the extrapolation to time zero of the intracellular component of the washout curve the initial intracellular radioactivity of both muscles was obtained and the resting and extra Na+ influx were calculated.4. The mean surface membrane area/muscle weight ratio was found to be 552 cm2.

show abstract

Section: Methodssupporting

confidence: 72%

Inward movement of sodium ions in resting and stimulated frog's sartorius muscle

Venosa¹

1974

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…Despite Overton's (1902) opinion to the contrary, it seems now to be widely accepted that when resting muscle fibres are placed in physiological solutions whose effective osmotic strength is not too far from normal (say 0 7 x R to 2 x R, 160-460 m-osmolal) water is gained or lost according to simple osmotic laws (see Hill, 1930;Fenn, 1936;Chao & Chen, 1937;Sato, 1954 Howarth, 1958) and causes some leakage of potassium, but no permanent harm is done. Incidentally, this concentration is nowhere near what can be borne by some specialized marine creatures (Bayliss, 1960, p. 73).…”

Section: Discussionmentioning

confidence: 99%

“…Even in the strongest solutions muscles lose only about 20 % of their initial weight (see Loeb, 1897;Cooke, 1898). Overton (1902) showed that even when allowance was made for dry matter and for an extracellular space of about 20 % (corrections not adequately appreciated by his predecessors), there was still a discrepancy between the calculated and the measured changes in the weight of the muscle. He accounted for this by proposing that about a fifth of the water was bound within the cell in the form of 'Quellungswasser', which could not be displaced except by very large gradients of vapour pressure (see his pp.…”

mentioning

confidence: 99%

The osmotic properties of striated muscle fibres in hypertonic solutions

Dydyńska¹,

Huxley²,

Page³

et al. 1963

The Journal of Physiology

141

View full text Add to dashboard Cite

It has been known for many years that, when muscles are placed in hypertonic solutions, their loss in weight is generally less than would be expected if the muscle were a simple osmotic sac. Even in the strongest solutions muscles lose only about 20 % of their initial weight (see Loeb, 1897;Cooke, 1898). Overton (1902) showed that even when allowance was made for dry matter and for an extracellular space of about 20 % (corrections not adequately appreciated by his predecessors), there was still a discrepancy between the calculated and the measured changes in the weight of the muscle. He accounted for this by proposing that about a fifth of the water was bound within the cell in the form of 'Quellungswasser', which could not be displaced except by very large gradients of vapour pressure (see his pp. 139-142, 155). Overton's conclusion was disputed by Hill (1930), who showed that almost all the fibre water could dissolve solutes in a normal manner. The assumption that all the water in muscle fibres participates in osmotic effects was later shown to lead to a satisfactory explanation of the weight changes in mildly hypotonic and hypertonic solutions . It seemed to us that the discrepancy in strongly hypertonic solutions might be explained by Overton's own qualitative observation, that in such solutions the extracellular space appeared to be increased.In this paper we have confirmed and extended this observation of Overton's by actual measurement of the extracellular (sucrose) space in solutions with various osmotic strengths. This permits, by subtraction, a direct calculation of the amount of fibre water as a function of osmotic strength. It then turns out that in solutions up to four or five times as concentrated as normal Ringer's solution the muscle fibres behave as simple semipermeable bags containing a fixed amount of solute: there is no need to invoke binding of any appreciable part of the fibre water.

show abstract

“…From the Physiological Laboratory, University of Cambridge (Received 20 April 1959) When Overton (1902) studied the excitability of frog muscle in different media, he found that lithium was the only cation which could be substituted for sodium without causing the fibres to become inexcitable. This suggests that in some ways the behaviour of the muscle membrane towards lithium must be similar to its behaviour towards sodium.…”

Section: By R D Keynes and R C Swanmentioning

confidence: 99%