ISSN:
1432-1912
Keywords:
α-Adrenoceptors
;
α1A-Adrenoceptors
;
α1B-Adrenoceptors
;
Second messenger
;
Inositol phosphates
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary We used novel highly subtype-selective antagonists to study whether α1A- and/or α1B-adrenoceptors mediate the stimulation of inositol phosphate generation by noradrenaline in rat cerebral cortex. Phentolamine (10 μM) and prazosin (100 nM) completely abolished the stimulated inositol phosphate generation. The α1A-selective antagonists 5-methyl-urapidil (100 nM) and (+)− and (−)-niguldipine (10 nM) caused only weak inhibition or none at all although these concentrations occupied α1A-adrenoceptors almost completely. In contrast, pretreatment with the irreversible α1B-selective chloroethylclonidine reduced the noradrenaline-stimulated inositol phosphate generation by 76 ± 8%. These data demonstrate that α1B-adrenoceptors couple to inositol phosphate generation; the signal transduction system of α1A-adrenoceptors remains unclear.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00180666
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