Characterization of sucrose-induced changes in cardiac phenotype.
The neuroendocrine factors responsible for long-term regulation of cardiac contractile performance remain ill defined. We examined influences of diet on the expression of myosin isozymes, sarcoplasmic reticulum (SR) Ca(2+) uptake and serum parameters. Dietary regimens (ad libitum feeding, intermittent fasting and 32% sucrose feeding) were used to alter the neurohumoral status of rats. Intermittent fasting decreased serum insulin levels ( P<0.05) and was associated with decreased SR Ca(2+) uptake and myosin V1 proportion ( P<0.05). Sucrose (32%) feeding increased myosin V1 of fasted and ad libitum fed rats ( P<0.05) but had no effect on insulin or SR Ca(2+) uptake. Expression of the alpha-myosin heavy chain correlated with serum insulin. Treatment of sucrose-fed rats with the sympatholytic compound moxonidine and the hypoglycaemic compounds BM13.907 and ciglitazone partially prevented the increase in myosin V1 ( P<0.05) but had no effect on SR Ca(2+) uptake and insulin. The data show that adrenergic activity and metabolic signals are important for an increase in myosin V1 in sucrose-fed rats, which can be associated with an unaltered SR Ca(2+) uptake rate.
Rupp
Heinz
H
Department of Internal Medicine and Cardiology, Karl-von-Frisch-Strasse 1, 35033 Marburg, Germany. Rupp@mailer.uni-marburg.de
Wahl
Richard
R
Maisch
Bernhard
B
Hansen
Matthias
M
D000818:Animals; D002118:Calcium / Q000493:pharmacokinetics; D019422:Dietary Sucrose / Q000008:administration & dosage*; D006321:Heart / Q000187:drug effects* / Q000502:physiology*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007328:Insulin / Q000097:blood; D018995:Myosin Heavy Chains / Q000378:metabolism; D010641:Phenotype; D051381:Rats; D017208:Rats, Wistar; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D013565:Sympatholytics / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D045162:Thiazolidinediones; D024723:Ventricular Myosins / Q000378:metabolism
D019422:Dietary Sucrose; D007004:Hypoglycemic Agents; D007093:Imidazoles; D007328:Insulin; D013565:Sympatholytics; D013844:Thiazoles; D045162:Thiazolidinediones; C043482:moxonidine; D024723:Ventricular Myosins; D018995:Myosin Heavy Chains; D002118:Calcium; C039671:ciglitazone