Influence of nicardipine on the morphology, calcium and cAMP level of immune organs in mice

Nicardipine, 10 mg/kg sc qd x 4d, caused morphological changes of immune organs in mice. The germinal centers of lymph nodes markedly reduced. The white pulps of spleens and the cortex of thymuses atrophied slightly. In these lymphoid tissues, the small lymphocytes markedly increased and the heterochromatin of nuclei increased. In the subcellular level, nicardipine damaged the structure of mitochondria in various cells. The lymphocytes in peripheral blood and the calcium content and cAMP level in immune organs markedly decreased. These results suggest that nicardipine inhibited proliferation of lymphocytes in vivo, and this effect was probably associated with the decreasing calcium content in immune organs. Influence on the structure and functions of mitochondria may be one of the mechanisms of nicardipine inhibiting functions of immune cells.