Ketosis induced by starvation or feeding a ketogenic diet has widespread and often contradictory effects due to the simultaneous elevation of both ketone bodies and free fatty acids. The elevation of ketone bodies increases the energy of ATP hydrolysis by reducing the mitochondrial NAD couple and oxidizing the coenzyme Q couple, thus increasing the redox span between site I and site II. In cont...

It is common knowledge that the intensity of ketosis is greater in man than in the dog. The question arises whether the difference is one of degree or of kind. The rate of development of ketosis, blood and urine acetone body concentration, and response to oral glucose have therefore been compared in the two species in order to determine whether such information would or would not suggest the pr...

The small intestine is the major site of glutamine utilization in the mammalian body. During prolonged (40-day) streptozotocin-diabetes in the rat there is a marked increase in both the size and the phosphate-activated glutaminase activity of the small intestine. Despite this increased capacity, intestinal glutamine utilization ceases in diabetic rats. Mean arterial glutamine concentration fell...

Rates of plasma acetoacetate and total ketone-body production and oxidation to CO2 were determined by an isotope tracer technique in eight obese subjects undergoing progressive starvation. After a brief fast and under conditions of mild ketonemia and minimal ketonuria, rates of acetoacetate and total ketone-body production and oxidation were directly related to the increasing plasma concentrati...

In this issue (P94), Kutoh reports type 2 diabetic patients who showed changes in cardiac function which is concomitant with changes in ketone bodies by using one of sodium glucose cotransporter 2 inhibitors (SGLT2i), tofogliflozin [1], proposing a possible mechanism for SGLT2i-mediated prevention of heart failure. EMPA-REG OUTCOME trial showed a striking relative risk reduction in hospitalizat...

The extension of life span by caloric restriction has been studied across species from yeast and Caenorhabditis elegans to primates. No generally accepted theory has been proposed to explain these observations. Here, we propose that the life span extension produced by caloric restriction can be duplicated by the metabolic changes induced by ketosis. From nematodes to mice, extension of life spa...

The metabolism of FFA and ketone bodies was studied in fasted rats by infusing at a constant rate tracer amounts of FFA-(3)H, beta-hydroxybutyrate-(14)C or acetoacetate-(14)C for periods up to 2 hr. Blood that was removed for analyses was replaced by continuous transfusion. The rates of turnover of FFA, beta-hydroxybutyrate, and acetoacetate in rats fasted for 2 days were, respectively, 3.2, 5....