Calcitonin gene-related peptide expression altered in pulmonary neuroendocrine cells in an experimental model of uraemia

The undertaken studies is aimed at immunohistochemical localisation, quantitative assessment and functional evaluation of neuroendocrine cells in the lungs of rats with experimentally induced uraemia. Lung and trachea fragments were collected after 1, 2 and 4 weeks from nephrectomy. Paraffinembedded sections were stained with haematoxylin and eosin and by silver impregnation. An immunohistochemical reaction was then performed with the use of a specific antibody against calcitonin-gene related peptide (CGRP) to identify neuroendocrine cells. Obtained results of the performed studies demonstrated a significantly increased number of CGRP-immunopositive cells in the lungs of applied uraemic rats (4.47±0.97, 7.62±1.61 and 5.72±2.5 neuroendocrine cells/mm2 of lung section after the 1st, the 2nd and the 4th week, respectively), when compared with that in the control (1.22±0.47 neuroendocrine cells/mm2 of lung section). The obtained results may be approached as a morphological expression of neuroendocrine cells hyperfunction in the lungs in result of disturbed internal body environment caused by renal parenchyma impairment. The enhanced activity of neuroendocrine cells, observed in the lungs of uraemic rats, was confirmed by results of studies of morphometric parameters, such as: area, diameter, length, width and the circularity index.