Circadian rhythm in adenosine A1 receptor of mouse cerebral cortex.
In order to investigate diurnal variation in adenosine A1 receptors binding parameters, Bmax and Kd values of specifically bound N6 - cyclohexyl-[3H]adenosine were determined in the cerebral cortex of mice that had been housed under controlled light-dark cycles for 4 weeks (light on from 7.00 to 19.00 h). Significant differences were found for Bmax values measured at 3-hr intervals across a 24-h period, with low Bmax values during the light period and high Bmax values during the dark period. The amplitude between 03.00 and 18.00 hr was 33%. No substantial rhythm was found in the Kd values. It is suggested that the changes in the density of A1 receptors could reflect a physiologically-relevant mechanism by which adenosine exerts its modulatory role in the central nervous system.
Florio
C
C
Institute of Pharmacology and Pharmacognosy, University of Trieste, Italy.
Rosati
A M
AM
Traversa
U
U
Vertua
R
R
D000241:Adenosine / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D002940:Circadian Rhythm; D007700:Kinetics; D008297:Male; D051379:Mice; D011983:Receptors, Purinergic / Q000378:metabolism*
D011983:Receptors, Purinergic; C027513:N(6)-cyclohexyladenosine; D000241:Adenosine