On the rhythmic activity of the oesophagus : and the influence upon it of various media ... / P.G. Stiles.

  • Stiles, Percy Goldthwait, 1875-1936.
Date:
1902
Catalogue details

Licence: In copyright

Credit: On the rhythmic activity of the oesophagus : and the influence upon it of various media ... / P.G. Stiles. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    be held by recent writers on pharmacology and it receives no support from the behavior of the oesophageal muscle in the presence of NaC103. The strips can be transferred from chloride to chlorate Ringer and back again without significantly changing the character of the record ; it is not apparent that one is more favorable than the other. It may be remarked that the record in chlorate Ringer is likely to be irregular, large contractions mingling with small. One of the longest records secured was that of a preparation in chlorate Ringer, the strip being active until the forty-ninth hour. Salts capable of replacing much of the chloride but not all. — The four salts already mentioned (NaN03, NaBr, Nal, NaC103) were the only ones found which could be freely used in place of NaCl. But a num- ber were found capable of replacing a large fraction of the chloride. These were organic salts including three members of the fatty series — formate, acetate and butyrate — and the tartrate and lactate. A description of the effects of sodium acetate will answer for any of the others. A solution of about 1.2 per cent is isotonic with 0.7 per cent NaCl. If a Ringer's solution is made up with acetate instead of NaCl, retaining CaCl2 and KC1 in the usual amounts, the active strip soon comes to rest when immersed in it. There may be a transient ex- aggeration of the movements, but they are presently slowed and the tone declines, leading to a standstill within twenty minutes. When such a relaxed strip is returned to normal Ringer it does not at once revive. It may be quiescent for an hour, but the beat is almost sure to be renewed and there seems to be no lasting effect from the acetate. The tissue will tolerate a large percentage of sodium acetate if a certain amount of the chloride (or interchangeable salt) is retained in the medium. The proportion of the NaCl that may be replaced by organic salts without checking the contractions is vari- able. It is safe to say that one half the NaCl may be so replaced by acetate without markedly depressing the activity of the strip. Some- times the substitution can be pushed farther and strips may beat for hours in solutions containing two or even three parts of the organic salt to one of the inorganic. This was shown most successfully in trials with sodium formate and sodium butyrate. In the presence of an excess of the organic salt, the rate at which the contractions occur is usually slowed. It should be noted that these sodium salts of organic acids are largely dissociated in the concentration employed. This precludes the inference that the inhibition brought about by them is due to a diminution in the number of Na ions.