Constitutive activity of beta-adrenergic receptors in C6 glioma cells.
Alprenolol and propranolol (0.001-10 microM) significantly and concentration-dependently inhibited both isoprenaline-driven and basal (non-stimulated) cyclic adenosine monophosphate (cAMP) accumulation in the rat C6 glioma cells, showing high potency particularly in the latter condition (IC 50 values of 30 and 27 nM, respectively). In the rat cerebral cortical slices, these two tested beta-adrenoceptor antagonists inhibited the isoprenaline-evoked cAMP response, but had no effect on the nucleotide accumulation under basal (non-stimulated) conditions. The obtained results suggest that native beta-adrenoceptors occurring in C6 glioma cells may be constitutively active.
Sokołowska
Paulina
P
Center for Medical Biology, Polish Academy of Sciences, Lodowa 106, PL 93-232 Łódź, Poland.
Nowak
Jerzy Z
JZ
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001932:Brain Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000032:analysis / Q000096:biosynthesis; D005910:Glioma / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D007545:Isoproterenol