S. Neubauer et al., Downregulation of the Na+-creatine cotransporter in failing human myocardium and in experimental heart failure, CIRCULATION, 100(18), 1999, pp. 1847-1850
Citations number
18
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Background-The failing myocardium is characterized by depletion of phosphoc
reatine and of total creatine content. We hypothesized that this is due to
loss of creatine transporter:protein.
Methods and Results-Creatine transporter protein was quantified in nonfaili
ng and failing human myocardium (explanted hearts with dilated cardiomyopat
hy [DCM; n = 8] and healthy donor,hearts [n = 8]) as well as in experimenta
l heart failure (residual intact left ventricular tissue, rats 2 months aft
er left anterior descending coronary artery ligation [MI; n = 8] of sham op
eration [sham; n = 6]) by Western blotting. Total creatine content was dete
rmined by high-performance liquid chromatography. Donor and DCM hearts had
total creatine contents of 136.4 +/- 6.1 and 68.7 +/- 4.6 nmol/mg protein,
respectively (*P < 0.05); creatine transporter protein was 25.4 +/- 2.2 opt
ical density units in donor and 17.7 +/- 2.5 in DCM (*P < 0.05). Total crea
tine was 87.5 +/- 4.2 nmol/mg protein in sham and 65.7 +/- 4.2 in MI rats (
*P < 0.05); creatine transporter protein was 139.0 +/- 8.7 optical density
units in sham and 821 +/- 4.0 in MI (*P < 0.05).
Conclusions-Both in human and in experimental heart failure, creatine trans
porter protein content is reduced. This mechanism may contribute to the dep
letion of creatine compounds and thus to the reduced energy reserve in fail
ing myocardium. This finding may have therapeutic implications, suggesting
a search for treatment strategies targeted toward creatine transport.