Using a non-recirculating perfusion system, we studied the time course of ketone body output from the isolated rat liver in response to various hormones and changes in pH and redox state. The release of 3-hydroxybutyrate (3-OHB) started to be suppressed within 1 min after the addition of insulin (50 mU/ml) and kept half of the basal level even 10 min after its cessation. The addition of glucago...

Oleate (1 mM) had only small inhibitory effects on glucose utilization and lipogenesis in acini isolated from rat mammary gland. Esterification of [1-14C]oleate was unaffected by insulin but was decreased by 60% by acetoacetate (2mM). Glycerol (1mM), but not insulin, relieved this inhibition. These experiments provide further support for the role of acetoacetate in regulating substrate utilizat...

Experiments were carried out to study the effect of acetoacetate admini stration on pyridine nucleotides in liver and blood in male albino rats. Acetoacetate, when administered along with tryptophan (through diet) to tryptophan-niacin-deficient rats for twenty days, resulted in decreased pyridine nucleotide values as compared to the corresponding controls. Prolonged administration of acetoaceta...

A comparison has been made in vivo between IS+)-3hydroxy[3-Wlbutyrate, o(-)-3-hydroxy[3-“‘Clbutyrate, [3Wlacetoacetate, and n-[Z-Wlglucose for sterol and fatty acid synthesis and respiration in the B-day-old suckling rat. (a) Sterols and fatty acids in spinal cord, brain, and skin were preferentially labeled by these metabolites over sterols and fatty acids in the liver and kidneys. (b) More la...

It is known that hyperglycemic-glycogenolytic factor (HGF) and epinephrine accelerate glycogenolysis in the liver. The studies of Sutherland and Cori (1) show that they act alike on the formation of glucose from glycogen in liver slices. Fat metabolism is also affected by these hormones. For example Blixenkrone-M@ller (2) observed that epinephrine causes an increase in the production of acetoac...

The rates of conversion into 14CO2 of D-(-)-3-hydroxy[3-14C]butyrate, [3-14C]acetoacetate, [6-14C]glucose and [U-14C]glutamine were measured in the presence and absence of unlabelled alternative oxidizable substrates in whole homogenates from the brains of young and adult rats. The addition of unlabelled glutamine resulted in decreased 14CO2 production from [6-14C]glucose in brain homogenates f...

FT UMAX KETONEMIA and ketonum-ia are manifestations of marked metabolic dysfunction arising fi-ommi mci-eased lipid nietabohism, frequently caused by several disease entities, and indicating the iimabihity of time periplmeral tissues’ to imandle time mci-ease(1 output of these metabolic products by time liver. At time presehit time, it is customam-y to follow a patient’s progm-ess by qualitativ...

1. The colorimetric method for estimation of acetoacetate by reaction with diazotizedp-nitroaniline has been adapted for measurements of oxaloacetate in amounts of 0 003-0 03 Htmole. 2. The steady-state level of oxaloacetate in the livers of normal and fasted rats was found to be about 4 umoles/100 g. dry wt. of tissue. The level was essentially unchanged in starvation when the level of acetoac...

Several authors have recently re-emphasized the positive interference of acetoacetate in the measurement of creatinine using the Jaff6 reaction [1-3]. On theoretical grounds, the measurement of creatinine in the presence of acetoacetate should be possible using a kinetic method [4]. In practice, however, measurements by some instruments employing a kinetic Jaff6 method suffer from marked interf...

Phosphoenolpyruvate carbosylase (EC 4.1.1.31) has been used in developing a simple, inexpensive colorimetric assay for serum total carbon dioxide in an open system. The oxaloacetate formed by the action of the enzyme on bicarbonate and phosphoenolpyruvate is measured by use of the diazonium salt of Fast Violet B. Interferences from billirubin, pyruvate, and drugs are negligible. Acetoacetate in...