Effects of 3-hydroxybutyrate on the hypoxic and reoxygenated atria from fed and fasted rats.
When exposed to hypoxia, the isolated atria from fed rats released lactate into the medium and underwent a decline of the peak developed tension and pacemaker frequency. The atria from 24-h fasted rats showed a rise in the resting tension together with a greater decline of the pacemaker rate and a lower lactate output than those from fed rats. The exposure to 5 mM 3-hydroxybutyrate caused only a small and brief decline in the pacemaker rate in the fed rats atria indicating that ketone bodies are able to exert only a minor detrimental effect on the hypoxic atria. Since the lactate output remained unaffected, this effect cannot be ascribed to a lowering in the energy supply from anaerobic glycolysis. On the contrary, 3-hydroxybutyrate improved the post-hypoxic recovery of the peak tension in the atria from fasted rats. This finding may be reflecting an anaplerotic role of 3-hydroxybutyrate, thus suggesting that in addition to glucose a second substrate is needed to meet the energy demand in the reoxygenated atria from fasted rats.
Varela
A
A
Cátedra de Fisiología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
Testoni
G
G
Carregal
M
M
Dalamon
V
V
Savino
E A
EA
D020155:3-Hydroxybutyric Acid; D000818:Animals; D016275:Atrial Function; D015687:Cell Hypoxia / Q000187:drug effects; D004435:Eating / Q000502:physiology; D005215:Fasting / Q000502:physiology; D005260:Female; D006325:Heart Atria / Q000187:drug effects* / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D006885:Hydroxybutyrates / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D006885:Hydroxybutyrates; D010100:Oxygen; D020155:3-Hydroxybutyric Acid