Gene expression of SERCA2a and L- and T-type Ca channels during human heart development

In this study we report, for the first time, on the gene expression of huma n cardiac SERCA2a, L-type (alpha (1C)) and T-type (alpha (1H)) Ca channels during development, using RNase protection assay, relative quantitative RT- PCR and Western blot. Human hearts during early gestation (8- to 20-wk gest ation), neonatal (Ito 4-d-old) and adult (18- to 48-year-old) stages were u sed. The results show that T-type Ca channel alpha (1H) subunit mRNA decrea sed and that L-type Ca channel alpha (1C) subunit mRNA increased with devel opment. While the levels of sarcoplasmic reticulum ATPase (SERCA2a) mRNA di d not significantly change with development, its protein levels increased w ith development. In conclusion, SERCA2a, L-type and T-type Ca channel trans cripts were detected as early as 8-wk gestation. Defining the profile of Ca handling proteins during development is important to the understanding of excitation-contraction (EC)-coupling of the developing human heart.