INSULIN FROM FISH.

Otago Daily Times, Issue 19615, 20 October 1925, Page 10

INSULIN FROM FISH.

RECENT EXPERIMENTS

PROFITABLE SOURCE OF SUPPLY

(From Opr Own Correspondent, j

LONDON, August 28. 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 showed what prevented diabetes, said Professor Macleod. but we still had, to find out whv diabetes occurred when it was not present in the body. It furnished a key that might unlock 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 mode experiments on the behaviour of sugar in fish. ’ As the latter were cold-blooded 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 1 changes in the l>ody 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 was 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 melded 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 principal 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 fisli were gutted at sea were so great as to make this an unsuitable source of supply. PURIFICATION PROCESSES.

Dr C. H. Beat, 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 approximately 2800 units of insulin per kilogramme of beef pancreas were obtained. In the original experiments of Banting and Beat some four or five units of insulin were obtained. Tha 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 Goeling on the purification of insulin, he' said that Best and EidoUt had been unable to confirm the work of the St. Bonis workers who reported that the lactic acid in the blood after the injection of insulin increased in the sable rate as the dextrose decreased.