Increased ketone utilization by the kidney reduces renal lactate uptake but does not affect tubular sodium reabsorption.

The purpose of the present study was to assess whether a moderate increase in ketonemia interferes with renal uptake of energy-providing substrates, and whether it may promote natriuresis similar to that occurring spontaneously during the early phase of starvation. To this end, the sodium salt of D(-)3-hydroxybutyrate (3OHB) was infused to 10 anesthetized dogs at a rate of 20 mumol/kg.min-1 over 135 minutes.

Stabilization of left ventricular function with D-(-)-3-hydroxybutyrate after coronary occlusion in the intact dog.

The D-(-) isomer or natural form of 3-hydroxybutyrate (D-(-)-3OHB) is a readily used energy substrate. Studies on anesthetized intact dogs in our laboratory have demonstrated that raising the arterial level of D-(-)-3OHB to 1 mM enhances the ketone uptake not only by the normal, but also by the acutely ischemic myocardium, though at a lower rate. Whether this moderate rise in arterial D-(-)-3OHB does modify the time course of left ventricular (LV) function during acute regional ischemia remains unsettled.

In vivo effect of the D-(-) isomer or natural form of 3-hydroxybutyrate on initial release of lactate dehydrogenase from the acutely ischaemic myocardium.

D-(-)-3-hydroxybutyrate, the isomer found in the circulation and in the urine of diabetic patients, generally is believed to be the physiologically important form of 3-hydroxybutyrate [10]. Little is known concerning the effects of an elevated plasma level of the D-(-) isomer of 3-hydroxybutyrate upon the acutely ischaemic heart. Using anaesthetized intact dogs with a balloon catheter inserted into the proximal part of the left anterior descending coronary artery (LAD), we have recently demonstrated that a 1 mM ketonaemia induced with the arginine salt of D-(-)-3-hydroxybutyric acid reduces the uptake of non-esterified fatty acids (NEFA) in the myocardial area distal to the inflated balloon [4].

The mechanism of the prolonged stimulatory effect of corticotrophin on pregnenolone production by guinea-pig adrenocortical mitochondria.

The postulated prolonged stimulatory influence of ACTH on the adrenocortical mitochondrial synthesis of pregnenolone in response to ACTH was studied in adrenal mitochondria isolated from control guinea-pigs and from animals treated s.c. with 100 micrograms ACTH(1-24) twice daily on the day before the animals were killed.

Inhibitory effects of the D(-)isomer of 3-hydroxybutyrate on cardiac non-esterified fatty acid uptake and oxygen demand induced by norepinephrine in the intact dog.

The effects of ketosis on the norepinephrine-induced high rates of cardiac uptake of non-esterified fatty acids (NEFA = free fatty acids = FFA) and oxygen consumption were studied in anesthetized intact dogs. After a control infusion of norepinephrine (500 ng/kg.min into the left ventricle), the D(-) isomer or natural form of 3-hydroxybutyrate was infused intravenously as the arginine salt at rates of 20 mumol/kg.