Ca(2+)-antagonistic action of bevantolol on hypothalamic neurons in vitro: its comparison with those of other beta-adrenoceptor antagonists, a local anesthetic and a Ca(2+)-antagonist.
The Ca(2+)-antagonistic action of bevantolol, a beta 1-adrenoceptor antagonist, on high- and low-voltage activated Ca2+ currents (HVA- and LVA-ICa) was examined on neurons dissociated from rat brain. Bevantolol (10(-6) to 10(-4) M) inhibited concentration-dependently both ICa. The IC50 value of bevantolol for LVA-ICa was 4 x 10(-5) M, while bevantolol at 10(-4) M inhibited HVA-ICa by 28.5 +/- 7.7%. The potency of bevantolol in inhibiting both ICa was greater than those of propranolol, labetalol and lidocaine, while the inhibitory action of bevantolol on voltage-activated Na+ current was weakest among them. Bevantolol may possess Ca(2+)-antagonistic action that is independent from local anesthetic action.
Omura
T
T
Research Laboratories, Nippon Chemiphar Co. Ltd., Saitama, Japan.
Kobayashi
T
T
Nishioka
K
K
Miyake
N
N
Akaike
N
N
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000779:Anesthetics, Local; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D007033:Hypothalamus, Middle / Q000166:cytology / Q000187:drug effects*; D008012:Lidocaine; D009474:Neurons / Q000187:drug effects*; D009529:Nicardipine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D011412:Propanolamines / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D000319:Adrenergic beta-Antagonists; D000779:Anesthetics, Local; D002121:Calcium Channel Blockers; D011412:Propanolamines; C021148:bevantolol; D008012:Lidocaine; D011433:Propranolol; D009529:Nicardipine