Gene expression of inflammatory mediators in different chambers of the human heart

Background. Inflammatory genes may be unevenly expressed in different heart chambers. Methods. Biopsies were taken simultaneously from the right atrium (RA), left atrium (LA), and left ventricle (LV) of 19 patients before cardioplegic arrest during open heart surgery. The mRNA expression of tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), inducible and endothelial nitric oxide synthase (iNOS and eNOS), endothelin-1 (ET-1), E-selectin (CD62E), intercellular adhesion molecule-1 (ICAM-1) and its ligand CD18, and CD25 was evaluated with semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Results. Expression of TNFα mRNA was higher in RA than LA and LV (p< 0.05), whereas IL-1β was more expressed in LA than RA (p< 0.05), which was higher than LV (p< 0.0001). There were no significant regional differences in the expression of ICAM-1, CD62E, CD25, iNOS, and eNOS. CD18 was higher in RA than LA (p< 0.05); ET-1 was more expressed in RA than LV (p< 0.04). Patients with stable angina had no expression of eNOS. Conclusions. Gene expression of inflammatory mediators was detected in the hearts of patients with different cardiovascular disorders, and was unevenly distributed in different heart chambers. Cardiac biopsies should be taken from the same site.