sodium-acetate--anhydrous and Ischemia

Developments in infusion therapy with sodium lactate administered with its isomer, and developments in acetate utilization, both as an infusate or a dialysate, have been previously described, as have the various effects of sodium acetate on cardiovascular function, metabolism and fluid replacement. Unfavorable effects of acetate infusate or dialysate, such as cardiovascular depression, have also been reported, and although the number of studies reporting favorable effects on cardiovascular metabolism is increasing, it is still a matter of controversy. It is clear, however, that acetate can be metabolized in the liver as well as in extrahepatic organs yielding bicarbonate, which can be utilized as an alkalizing agent. Recently, the authors reported new experimental findings that sodium acetate was metabolized to ketone bodies by the kidney during hepatic inflow occlusion. Ketone bodies attract considerable attention as energy substrates in the stress phase and in the reduced redox state. Administration of sodium acetate under such conditions may therefore contribute as substrate supply.

Topics: Adenosine Triphosphate; Animals; Humans; Ischemia; Isotonic Solutions; Ketone Bodies; Kidney; Liver; Oxidation-Reduction; Resuscitation; Sodium Acetate; Sodium Lactate; Vasodilation

We examined the effects of increasing acetylcarnitine and acetyl-CoA availability at rest, independent of pyruvate dehydrogenase complex (PDC) activation, on energy production and tension development during the rest-to-work transition in canine skeletal muscle. We aimed to elucidate whether the lag in PDC-derived acetyl-CoA delivery toward the TCA cycle at the onset of exercise can be overcome by increasing acetyl group availability independently of PDC activation or is intimately dependent on PDC-derived acetyl-CoA. Gracilis muscle pretreated with saline or sodium acetate (360 mg/kg body mass) (both n = 6) was sampled repeatedly during 5 min of ischemic contraction. Acetate increased acetylcarnitine and acetyl-CoA availability (both P < 0.01) above control at rest and throughout contraction (P < 0.05), independently of differences in resting PDC activation between treatments. Acetate reduced oxygen-independent ATP resynthesis approximately 40% (P < 0.05) during the first minute of contraction. No difference in oxygen-independent ATP resynthesis existed between treatments from 1 to 3 min of contraction; however, energy production via this route increased approximately 25% (P < 0.05) above control in the acetate-treated group during the final 2 min of contraction. Tension development was approximately 20% greater after 5-min contraction after acetate treatment than in control (P < 0.05). In conclusion, at the immediate onset of contraction, when PDC was largely inactive, increasing cellular acetyl group availability overcame inertia in mitochondrial ATP regeneration. However, after the first minute, when PDC was near maximally activated in both groups, it appears that PDC-derived acetyl-CoA, rather than increased cellular acetyl group availability per se, dictated mitochondrial ATP resynthesis.

Topics: Acetyl Coenzyme A; Acetylcarnitine; Adenosine Triphosphate; Animals; Dogs; Female; In Vitro Techniques; Ischemia; Isometric Contraction; Metabolic Clearance Rate; Muscle, Skeletal; Pyruvate Dehydrogenase Complex; Sodium Acetate; Stress, Mechanical