Enhanced Sarcolemmal FAT/CD36 Content and Triacylglycerol Storage in Cardiac Myocytes From Obese Zucker Rats
Article Figures & Tables
Figures
- FIG. 1.
Influence of SSO, insulin (Ins), and oligomycin (Oli) on the initial palmitate uptake rate in cardiac myocytes from lean and obese Zucker rats. [14C]palmitate uptake in 3 min was determined in cardiac myocytes from lean and obese Zucker rats either not treated (basal) or treated with 0.4 mmol/l SSO, 10 mmol/l insulin, or 30 μmol/l oligomycin and expressed as nanomoles per minute per gram of cell mass. Data are means ± SE, n = 8. *P < 0.05.
- FIG. 2.
Quantitation of Western blots of the LCFA transporter FAT/CD36 in total heart homogenates (n = 6; A) and LDM and SL compartment of cardiac myocytes from lean and obese Zucker rats (n = 8; B), under basal conditions or treated with 10 nmol/l insulin (Ins) or 30 μmol/l oligomycin (Oli). The FAT/CD36 protein content was expressed as the percent of FAT/CD36 content in nontreated cardiac myocytes from lean Zucker rats in the corresponding fractions. Data are means ± SE. *P < 0.05 vs. basal values in lean Zucker rats.
- FIG. 3.
Influence of SSO, insulin, and oligomycin on the palmitate oxidation rate in cardiac myocytes from lean and obese Zucker rats. 14CO2 production (palmitate oxidation) in 20 min was determined in cardiac myocytes from lean and obese Zucker rats either not treated (basal) or treated with 0.4 mmol/l SSO, 10 nmol/l insulin (Ins), or 30 μmol/l oligomycin (Oli) and expressed as nanomoles per minute per gram of cell mass. Data are means ± SE, n = 8. *P < 0.05.
- FIG. 4.
Cardiac TAG content in lean and obese Zucker rats, measured using HPTLC in heart homogenates and expressed as micrograms per milligram of protein. Data are means ± SE, n = 6. *P < 0.05 vs. lean Zucker rats.
- FIG. 5.
Influence of SSO, insulin, and oligomycin on [14C]palmitate esterification into TAGs and PLs in cardiac myocytes from lean and obese Zucker rats. Incorporation of [14C]palmitate into intracellular TAGs (A) and PLs (B) was determined after 20 min in cardiac myocytes either not treated (basal) or treated with 0.4 mmol/l SSO, 10 nmol/l insulin (Ins), or 30 μmol/l oligomycin (Oli) and expressed as nanomoles per minute per gram of cell mass. Data are means ± SE, n = 8. *P < 0.05.
- FIG. 6.
Influence of SSO, insulin, and oligomycin on the intracellular [14C]palmitate content in cardiac myocytes from lean and obese Zucker rats. The intracellular content of [14C]palmitate was determined after 20 min in cardiac myocytes either not treated (basal) or treated with 0.4 mmol/l SSO, 10 nmol/l insulin (Ins), or 30 μmol/l oligomycin (Oli) and expressed as nanomoles per minute per gram of cell mass. Data are means ± SE, n = 8. *P < 0.05.
Tables
- TABLE 1
Characteristics of lean and obese Zucker rats
Lean Obese Body weight (g) 184 ± 18 333 ± 35* Heart weight (g) 0.98 ± 0.08 1.30 ± 0.12* Glucoseplasma (mmol/l) 11.5 ± 1.3 13.5 ± 2.3 Insulinplasma (nmol/l) 0.44 ± 0.29 3.14 ± 0.65* Triacylglycerolsplasma (mmol/l) 0.36 ± 0.07 2.06 ± 1.43* Data are means ± SE for 8–10 rats.
- *
* P < 0.05 vs. lean Zucker rats.
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