Endogenous triacylglycerol utilization by the isolated rat atria.
The isolated atria from 24 h fasted rats, either in the presence of glucose or in a substrate-free medium containing 2-deoxyglucose, mobilized the endogenous triacylglycerol (TG) to a greater extent than those from fed rats. The TG of the fasted atria had almost disappeared at the end of the 90 min incubation in the substrate-free plus 2-deoxyglucose medium, whereas in those from fed rats a mobilization-resistant portion of about 40% of the TG pool remained. This finding coincided with a lower decay of the contractile and pacemaker activities in the atria from fasted rats. Insulin abolished the TG mobilization in the atria from fed rats in the presence of glucose, but it was ineffective in the fasted atria. These data suggest that the endogenous-TG and glucose share in supporting the atrial functions, that insulin is involved in the control of TG consumption only in the fed state and that the greater TG mobilization in the fasted atria, at least partly, meets the energy requirements of the tissue.
Varela
A
A
Orientación Fisiología Humana, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, República Argentina.
Savino
E A
EA
D000818:Animals; D005260:Female; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006325:Heart Atria / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D014280:Triglycerides / Q000378:metabolism*
D014280:Triglycerides; D006003:Glycogen; D005947:Glucose