The Metabolism of Carbohydrate and Volatile Fatty Acids in the Marsupial, Setonix Brachyurus

Quokkas have digestive and metabolic affinities with ruminants, whom they resemble in that their “normal” blood sugar levels are lower than those of non‐ruminants. Also, as in sheep, intravenous insulin has a greater and more prolonged effect on the blood sugar than in non‐ruminants. Injected glucose may possibly be cleared from the blood faster than in ruminants. In other respects, quokkas resemble more closely non‐ruminants. Thus, compared with ruminants, fasting lowers the blood sugar more rapidly and extensively; blood volatile fatty acid (VFA) levels are generally lower, except during feeding; injected VFA is cleared more quickly from the blood; injections of sodium propionate have a smaller effect on blood sugar; arterio‐venous differences of VFA are smaller and of glucose greater. A previous report that blood VFA levels in quokkas were similar to those in ruminants was due to the effect of ethanol in the anæsthetic used. Ethanol causes a rapid increase in blood VFA levels in quokkas, rabbits and man.