RT-PCR detection of the Na,K-ATPase beta 3-isoform in human heart

The Na,K-ATPase is a heterodimer composed of an alpha -catalytic and a beta -glycoprotein subunit. At present, three different alpha -polypeptides (al pha1, alpha2, alpha3) and two distinct beta -isoforms (beta1 and beta2) hav e been detected in human heart. The aim of the present study was to determi ne whether or not the beta3-isoform of the Na,K-ATPase can be detected in h uman heart. Using the highly sensitive method of RT-PCR, we here show that human heart expresses the beta3-isoform of the Na,K-ATPase. Given the diffe rences in pharmacological properties of the nine different Na,K-ATPase isoe nzymes (containing all combinations of the subunit isoforms), the study of beta3-isoform regulation in human heart may be of interest in understanding the altered response of human myocardium to digitalis therapy during heart failure.