Muscarinic Acetylcholine Receptors on Human Lymphocytes in Patients with Meniere's Disease

Abstract

To investigate patients with Meniere's disease and the association of cholinergic hyperreactivity, we performed muscarinic acetylcholine receptor assay using peripheral blood lymphocytes from patients with Meniere's disease and non-dizzy, non-allergic control subjects. Cholinergic receptor maximal bindings (Bmax) and dissociation constants (Kd) were compared between the two groups, indicating the number and the affinities of the receptors, respectively. the receptor Bmax value in Meniere's patients during the remission state (108.6 ± 51.2 fmol/1 ± 10⁶ lymphocytes) was higher than that in normal controls (45.8 ± 9.2 fmol/1 ± 10⁶ lymphocytes) (p < 0.01). Furthermore, during an exacerbated state, Bmax was increased significantly (223.7 ± 90.2 fmol/1 ± 10⁶ lymphocytes) compared to the remission state (p <0.01). in contrast, Kd values for the receptor did not differ between the two groups. These results suggest that patients with Meniere's disease have cholinergic hyperreactivity, which may be further upregulated during a state of exacerbation due to an increase in the number of cholinergic receptors.

Key Words:

• cholinergic hyperreactivity
• receptor assay
• maximal binding of cholinergic receptor