Hyaluronan and alpha-atrial natriuretic polypeptide in human nasal polyps: contributing factors to oedema formation and polyp growth?

OBJECTIVES

To identify and localize hyaluronan (HYA) and alpha-atrial natriuretic polypeptide (ANP) in human nasal polyps and to measure the HYA concentrations.

MATERIAL AND

METHODS

Twelve nasal polyps were collected during routine polypectomies and processed histochemically and biochemically to determine the occurrence of HYA. The distribution of ANP was investigated using an immunocytochemical method.

RESULTS

HYA was unevenly distributed, being found abundantly in the surface epithelium and basement membrane and around fibres and vessels in the lamina propria. It was also present around seromucinous glands and in the secretion of cysts in the stroma. The HYA concentration was 1,000-fold higher than in serum. ANP was abundant in the apical part of ciliated surface epithelial cells and extracellularly in the basement membrane. In the stroma, ANP was confined to apical acinar cells of the seromucinous glands.

CONCLUSIONS

Osmotically active HYA and numerous ANP-immunoreactive cells, active in fluid and/or ion transport functions, are present in human nasal polyps. These substances may well be involved in oedema formation and the successive growth of nasal polyps. The high concentrations of HYA in nasal polyps may be of clinical significance for the future development of a local enzyme treatment for nasal polyposis.