Neural cell adhesion molecule expression in the human carotid body.

We studied by immunocytochemistry the expression of NCAM in human carotid bodies, sampled at autopsy from 16 adult subjects (mean age +/- SD: 44.3 +/- 3.4 years). No NCAM immunoreactivity was visible in type II cells. An high percentage (78.3 +/- 7.2%) of type I cells showed positive anti-NCAM immunoreaction. Statistically significant differences were not found in anti-NCAM immunostaining of light and dark cells (80.2 +/- 6.2% vs 74.7 +/- 13.4%, P>0.05). The high expression level of NCAM in the carotid body indicates a role in regulating adhesion between type I cells. The ascertained role of NCAM in neural mechanisms of differentiation, survival and cell plasticity suggests a possible involvement in the development/differentiation process of the carotid body and in determining cellular/molecular changes due to chronic hypoxia.