Normalization of deranged signal transduction in lymphocytes of COPD patients by the novel calcium channel blocker H-DHPM
S. Manral, S. Bhatia, R. Sinha, A. Kumar, V. Rohil, A. Arya, A. Dhawan, P. Arya, R. Joshi, S. C. Sreedhara, S. Gangopadhyay, S. K. Bansal, S. Chatterjee, N. K. Chaudhury,..., V. S. Parmar, A. L. DePass, A. K Prasad, H. G. Raj – 2011
Investigations on the role of intracellular Ca(2+) ion concentration in the mechanism of development of COPD in smokers and non-smokers were carried out. The intracellular Ca(2+) levels were found to be increased in human lymphocytes in patients with COPD as compared to non-smokers and smokers without COPD. The investigations reveal an association in altered intracellular Ca(2+) regulation in lymphocytes and severity of COPD, by means of significant activation of Protein kinase C and inducible nitric oxide synthase (iNOS). The effect of a novel calcium channel blocker ethyl 4-(4'-heptanoyloxyphenyl)-6-methyl-3,4-dihydropyrimidin-2-one-5-carboxylate (H-DHPM) as a potential candidate for the treatment of COPD was also investigated. H-DHPM treated cells showed a decrease in intracellular Ca(2+) level as compared to the control cells. Molecular studies were carried out to evaluate the expression profile of NOS isoforms in human lymphocytes and it was shown that H-DHPM decreases the increased iNOS in COPD along with reestablishing the normal levels of endothelial nitric oxide synthase (eNOS). The results of H-DHPM were comparable with those of Amlodipine, a known calcium channel blocker. Calcium channel blocker H-DHPM proves to be a potential candidate for the treatment of COPD and further clinical studies are required to prove its role in the treatment of pulmonary hypertension (PH).