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Although a growing body of evidence supports that alkali therapy in diabetic ketoacidosis (DKA) might be counterproductive, our knowledge about the consequences of this treatment on ketone metabolism is limited. Consequently, we performed clinical and animal studies to further examine this topic. The clinical studies assessed seven patients with DKA treated with continuous insulin infusion at a low dosage. Three of them also received sodium bicarbonate (NaHCO3), whereas the remaining four acted as controls. The group receiving NaHCO3 showed a 6-h delay in the improvement of ketosis as compared with controls. In addition, there was an increase in acetoacetate (AcAc) levels during alkali administration, followed by an increase in 3-hydroxybutyrate (3-OHB) level after its completion. Significant differences were not found between groups in the response of plasma glucose to the overall therapy. The animal study examined the effects of a NaHCO3-rich perfusate on the hepatic production of ketones with the in situ rat-liver preparation. Alkali loading resulted in an immediate increase in the AcAc level followed by increases in both the 3-OHB level and the 3-OHB/AcAc ratio after its completion. Hepatic ketogenesis increased even further, to about twice the basal level, after termination of the NaHCO3 loading. This investigation confirms that alkali administration augments ketone production and unravels an effect of bicarbonate infusion that promotes a selective build up of AcAc in body fluids. The data support that alkali therapy in DKA has nonsaltuary effects in the metabolism and plasma levels of ketones.

The present studies were undertaken to quantitate the relative contributions of the indirect and direct pathways for hepatic glycogen repletion and to determine the role of splanchnic tissues in provision of C precursors used for the indirect pathway. For this purpose, we administered oral glucose (1.4 g/kg) enriched with [1-14C]glucose to 18-h fasted dogs and measured net hepatic and net gastrointestinal glucose, lactate, and alanine balance, hepatic and gastrointestinal fractional extraction [( 3H]lactate), release and uptake of lactate, as well as the total amount of hepatic glycogen formed from the oral glucose and the 14C labeling pattern of the glycogen-glucose C. Although net hepatic glucose uptake (8.7 +/- 0.6 g, 27% of the oral load) exceeded the amount of glycogen formed from the oral glucose (6.3 +/- 1.1 g), analysis of radioactivity in C-1 of the glycogen glucose indicated that nearly 50% of the glycogen was formed by the indirect pathway. Net hepatic uptake of lactate (1.4 +/- 0.1 g) and alanine (1.5 +/- 0.1 g) could account for greater than 90% of glycogen formed by the indirect pathway if all of the lactate and alanine taken up by the liver had been incorporated into glycogen. Release of lactate and alanine by splanchnic tissues approximated the amount of lactate and alanine taken up by the liver. However, in addition to taking up lactate, the liver also produced nearly as much lactate as the gastrointestinal tract (1.8 +/- 0.2 vs. 2.0 +/- 0.3 g, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

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