The inhibition of lactic acid formation in cancer and muscle / by Sylvia Thurlow Harrison and Edward Mellanby.

  • Harrison, Sylvia Thurlow.
Date:
[1930?]
Catalogue details

Licence: In copyright

Credit: The inhibition of lactic acid formation in cancer and muscle / by Sylvia Thurlow Harrison and Edward Mellanby. Source: Wellcome Collection.

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    A typical experiment using mouse carcinoma 63 is given below. Five Barcroft micro-apparatus, of the type having the manometer open at one end, were used, containing: 1. 0-4 cc. bicarbonate Ringer + 0-1 cc. pancreatic extract + 2-8 mg. tissue: 2. 0-4 cc. bicarbonate Ringer + 0-1 cc. heated pancreatic extract + 2-2 mg. tissue: 3. 0*4 cc. bicarbonate Ringer (0-2 % glucose) + 0-1 cc. pancreatic extract + 1-6 mg. tissue: 4. 0*4 cc. bicarbonate Ringer (0*2 % glucose) + 0-1 cc. heated pancreatic extract +1*8 mg. tissue. A fifth apparatus containing 0-5 cc. Ringer only was used as a temperature control. Apparatus 1 and 2 contained no glucose and therefore gave the C02 produced by oxidation processes. Apparatus 3 and 4 contained glucose, and any C02 given off beyond that produced in 1 and 2 was due to the glycolysis of glucose [Warburg, 1923]. The figures (multiplied by the apparatus constant and divided by tissue weight) for the above experiment are given below. They represent mm.3 C02 per mg. dry weight of tissue per hour. 1. Ringer + pancreatic extract + 0-5 2. ,, + heated extract — 1*7 3. „ + glucose + pancreatic extract +14-6 4. ,, + glucose + heated extract + 20-2 Glycolysis with pancreatic factor = (14*6 — 0-5) = 14T ,, without „ ,, = (20*2 + 1*7) = 21-9 In this experiment the pancreatic extract has caused an inhibition in aerobic glycolysis of 35 %. Previous workers using muscle hash had obtained inhibitions ranging from 40 to 60 %. A possible source of error lay in the fact that the buffering power of the pancreatic extract might have been lowered by heating and that hence the heated extract would not retain so much C02 as the unheated. If this were true, a correction factor would have to be applied to the observed readings. To test this possibility, an experiment was carried out according to Negelein’s [1925] method, and it was found that no extra retention of C02 occurred in the solution containing unheated pancreatic extract and that therefore no retention correction was necessary. Table I gives the results of experiments measuring the aerobic glycolysis of cancer tissue as affected by extracts of pancreas. The pancreatic extract made according to Foster and Woodrow is designated as F and W. The extracts marked “sterilised” were passed through a sterilising filter. It will be seen from Table I that in 15 of the 22 experiments the pancreatic extract caused an inhibition of glycolysis ranging from 15 to 100 %. During the course of these experiments, the work of Case and McCullagh [1928] appeared, which showed that the pancreatic factor inhibiting muscle glycolysis