Adrenoceptors in the Control of Human Nasal Mucosal Blood Flow

Abstract

The blood flow in the human nasal mucosa is controlled by the functional state of the resistance vessels. This blood flow was studied by means of the ¹³³Xe washout method. Using topical application of drugs that stimulate or block adrenoceptors, including clinical doses of nasal decongestants, we classified the adrenoceptors of the resistance vessels in the mucosa. The results suggest that stimulation of α₂-adrenoceptors causes a reduction of nasal mucosal blood flow; stimulation of α₁- and β₂-adrenoceptors seems to have no significant effects. Drugs that selectively stimulate α₂-adrenoceptors, as well as those with preference for α₁-adrenoceptors, cause nasal decongestion. To avoid the negative effects of a nasal mucosal blood flow reduction, it is suggested that a nasal decongestant with an α₁-adrenoceptor stimulating effect should be preferable to a drug acting mainly on α₂-adrenoceptors, provided that the decongestive effects are equal.