Expression of hemoglobin α and β subunits in different types of rat vasculatures

Abstract

Objective To clarify whether hemoglobin (Hb) α and β subunits are expressed in rat blood vessels, and whether there are differences in expression levels between different types of vasculatures. Methods RT-PCR, DNA sequencing and Western blotting were used to detect the expression of Hb α and β subunits at mRNA and protein levels in common carotid artery, thoracic aorta, superior mesenteric artery, femoral artery, external jugular vein, superior mesenteric vein and femoral vein in SD rats. Relative expression levels of Hb α and β subunits in these vessels were determined by probe qPCR. The results of immunofluorescence assay for Hb α and β subunits in these vessels was further observed by laser confocal microscopy. Results Specific DNA fragments were amplified from different blood vessels by RT-PCR, and the sequences of these DNA fragments were identical to the mRNA sequences of rattus norvegicus Hb α and β subunits in GenBank database respectively. Protein peptides with correct molecular weights were detected using antibodies against Hb α and β subunits respectively from total protein extracts of these blood vessels by Western blotting. qPCR results indicated that the relative expression levels of Hb α and β subunits varied between different blood vessels, and it was significantly lower in the thoracic aorta (Hb α=0.12, Hb β=0.11) while higher in the femoral vein (Hb α=7.23, Hb β=4.73) (P < 0.01). The results of immunofluorescence laser confocal microscopy indicated that Hb α and β subunits were expressed in vascular endothelial cells. Conclusion Hemoglobin α and β subunits are co-expressed in rat vasculatures, including conduit, resistance and capacitance vessels, and the relative expression level is higher in the resistance and capacitance vessels but lower in the conduit vessels.

Keywords

• hemoglobin
• blood vessels
• gene
• expression