CALCITONIN-GENE-RELATED PEPTIDE IMMUNOREACTIVITY IN ADULT-MOUSE LUNG

Calcitonin gene-related peptide (CGRP) is a 37 aminoacid peptide coded by the calcitonin gene that is produced by thyroid C cells and medull ary carcinoma. It is also widely distributed in neurons and endocrine cells throughout the body. The presence of CGRP in the lungs suggests that this peptide exerts important regulatory actions at this level, a nd it can act like a neuroregulator released both from nerve terminals and neuroendocrine (NE) cells. To understand the role of CGRP in the lung, it is important to explore its localization in different species . In this paper, we analyse the presence and localization of CGRP in t he adult mouse lung using an immunocytochemical staining method. Our r esults show a widespread distribution of this peptide in isolated neur oendocrine cells and neuroepithelial bodies (NEBs), as well as in nerv e fibres distributed in many areas of the lung, including bronchi and bronchioli. These fibres are in close contact with epithelium, neuroen docrine cells and smooth muscle. In addition, some immunostained nerve cell bodies and immunoreactive intrinsic ganglion cells can be shown. CORP has been previously demonstrated in the mammalian lung using imm unocytochemistry. To the best of our knowledge, this is the first time that CORP has been immunocytochemically demonstrated in the mouse lun g both in NE cells, NEBS, ganglion cells and in nerve fibres which an related to neuroendocrine cells.