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Hawera Star, Volume XLV, 26 October 1925, Page 9

INSULIN FROM FISH.

RECENT EXPERIMENTS. Professor J. R. R. Macleod and Dr. C. H. Best, both of Canada, gave the physiologists at the British Association Conference the latest information as regards insulin. Insulin sb owe d what prevented diabetes, said Professor Macleod, but we still had to find out why diabetes occurred when it was not present m the body. ~ It furnished a, key that mightunlock the door to a discovery of the cause, but we did not know how the key should be turned. In order to expand the line of attack on this problem the experimental station of the Biological Board of Canada had made experiments on the behaviouf of sugar in fish. As the.. latter were coldblooded the changes were much slower in the intermediate stages than they were in the case of mammals, and could be more closely followed. All fish had about the same amount of sugar in the blood as men and other mammals had, and the amount increased under some experimental conditions. This indicated that its changes in the body must be controlled in the same way. The fish must therefore possess insulin, and it had been found that this was secreted by special glands near the gall bladder. On the other hand, the pancreas, which wa6 the source of insulin in mammals, did not produce it. Now these special glands, or principal islets, as they are called, had the same structure as the Isles of Langerhans, thus showing that it must be because of the presence of the structure in the pancreas that the gland yielded it. When the principal islets were excised the blood sugar increased very greatly, indicating that the fish were diabetic. Insulin could be prepared very easily from the prihcipal islets, and in countries where the cleaning of fish was done on shore this should be a profitable source of supply. The difficulties of collecting islets when the fish were gutted at sea were so great as to make this an unsuitable source of supply. PURIFICATION PROCESSES. Dr. C. H. Best, of the University of Toronto, dealing with the preparation and purification of insulin and lactic acid in insulin hypoglycaemia, said that very considerable improvement in the yields of insulin from beef pancreas had resulted from the use of hydrochloric acid instead of sulphuric acid in the extraction. In the insulin large scale production at Toronto approximately 2800 units of insulin per kilogramme of beef pancreas were obtained.. In the original experiments of Banting and Best some four or five units of insulin were obtained. The insulin powder, as prepared by the method of Scott and Best, contained 25,000 units per gramme of material. After discussing the new work of Able and Gjoeling on the purification of insulin, he said that Best and Ridout had been unable to confirm the work of the St. Louis workers who reported that the lactic acid in the bloocT after the injection of insulin increased in the same rate as the dextrose decreased.