Circannual variation in the expression of β2-adrenoceptors on human peripheral mononuclear leukocytes (MNLs)

Abstract

Peripheral mononuclear leukocytes (MNLs) are widely used as a tissue model in studies of beta-adrenoceptor disturbances in hypertension and asthmatic diseases. The beta 2-adrenoceptor density (Bmax), however, depends not only on the gender of the person under study and on the time of day the blood specimens are obtained. Evidence is now reported for a circannual variation in the expression of beta 2-adrenoceptor sites on peripheral MNLs. In male volunteers the 24-h mean was found to be highest in the men studied in April/May (1135 +/- 10 sites/cell) and decreased to 891 +/- 16 sites/cell in August and to 712 +r90 sites/cell in December (means +/- SE, P less than 0.01 April/May compared to December). Concomitantly the circadian amplitude increased from 17.3% +/- 6.4% of 24-h mean in April/May to 28.2% +/- 1.4% of 24-h mean in August and to 34.2% +/- 4.2% of 24-h mean in December (means +/- SE, P less than 0.05, April/May compared to December). The circadian acrophase remained constant (190 degrees +/- 30 degrees equivalent to 12 h 40 min +/- 2 h 00 min, means +/- SE).

Some alterations of the leucoeyte β2‐adrenoceptor/cAMP‐system in patients with seasonal allergic rhinoconjunctivitis are related to disease activity

“…Both groups, however, patients as well as controls, showed a significantly lower PBL /Si-adrcnoceptor density at the second investigation in December/January as compared with the first determination in April/May. This confirms the earlier observed seasonal variation in the expression of PBL /32-adrenoceptors [24]. Because we were prepared to see such seasonal variations we took particular care to study not only alterations in the PBL iS^-adrenoceptor/cAMP system of atopic patients and their dependence on disease activity.…”

Defects of β2‐adrenergic signal transduction in chronic lymphocytic leukaemia: relationship to disease progression

“…Specific binding data (S ) were iteratively fitted to a two-binding site model by non-linear regression analysis using the Enzfitter program by D. Leatherborrow (Biosoft, Cambridge, UK) as described [14,21,22]. Binding data were also transformed according to Scatchard for visualization of the results [23].…”

Impairment of the β-Adrenergic System of Peripheral Blood Leukocytes in Atopic Patients with Seasonal Allergic Rhinoconjunctivitis

“…All samples were taken between 08.30 and 09.30 h in the morning to avoid that the results were influenced by circadian variations [7]. The study was performed in April/May.…”