Note upon the effect of stimulation of the accelarator nerve upon the calcium, potassium, and nitrogen metabolism of the isolated heart / by W.H. Howell and W.W. Duke.
- William Henry Howell
- Date:
- [1908?]
Licence: Public Domain Mark
Credit: Note upon the effect of stimulation of the accelarator nerve upon the calcium, potassium, and nitrogen metabolism of the isolated heart / by W.H. Howell and W.W. Duke. Source: Wellcome Collection.
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![showed any variation in amount, after a perfusion lasting for hours, and after long-continued excitation of the heart through its accelerator nerve. As an indication of the character of the results obtained, the protocols of two experiments may be given in detail, one of them being a control in which the accelerator was not stimulated, and one an experiment in which the accelerator was effective and was stimulated a great number of times. Experiment, May 1, 1908.— Cat, etherized and bled. Heart isolated. 11 A.M., beat well upon the stock solution, but accelerator nerves on stimulation gave no effect. At 11.45 A.M. placed on a special supply of 150 c.c. which was maintained in continuous circulation. At 12.45 P. M. the heart was excised and suspended in a covered funnel so that all the drip could be secured. A little new solution was added to the supply flask and the circulation was continued until 4.45 p.m. The temperature of the circulating liquid varied from 35° to 37°C. At the end of the ex- periment the heart was still beating well. The circulating liquid was slightly turbid. On acidulation and boiling very little increase in opales- cence could be detected. 10 c.c. were taken from the stock liquid and from the special supply of 150 c.c. which had been circulated through the heart for five hours. The solutions were evaporated to dryness, ashed, moist- ened with a few drops of HCl, again evaporated to dryness, dissolved in 25 c.c. water, of which 5 c.c. were used for determination of the potassium and 20 c.c. for the calcium. Calcium. — 8 c.c. of original Locke’s solution contained 0.955 mgm. Ca. 8 c.c. of the circulated solution contained 0.966 mgm. Ca. Potassium. —In colorimeter tle stock solution (B) compared with the standard solution of potassium chlorplatinate containing in each cubic centimetre 0.00265 mgm. K, gave the following reading; standard = 40; B= 49 Hence B contained 0.00216 mgm. K to eachc.c. Since the solution had been diluted 50 times, the original solution contained (0.00216 X 50 + 52.3) 0.21 mgm. KC] to each cubic centimetre, or o.o21 per cent KCI Compared with (B), the solution which had been perfused through the heart (A) gave the following reading: A= 40; B= 39 ‘Hence A contained 0.0105 per cent potassium compared with o.o108 per cent in B, the liquid before circulation.](https://iiif.wellcomecollection.org/image/b33441121_0006.jp2/full/800%2C/0/default.jpg)
