Neuraminidase reduces the number of super-high-affinity [ 3H]oxotremorine-M binding sites in lung

Abstract

The effects of neuraminidase on the binding of the radioligand agonist [ 3H]oxotremorine-M ([ 3H]oxo-M) were investigated in lung membranes. [ 3H]Oxo-M labelled super-high-affinity binding sites (K D of 1.36 nM), as indicated by the very high affinity displayed by carbachol when tested in competition with 0.5 nM [ 3H]oxo-M. Neuraminidase reduced the number of [ 3H]oxo-M binding sites with no change occurring in the K D. These results suggest that the effects of neuraminidase may explain virus-induced airway hyperresponsiveness.