Effects of bucumolol, nadolol and nifenalol on maximum upstroke velocity of action potential in guinea pig papillary muscles.
Ichiyama M, Sada S, Takahashi Y, Sada H, Ban T.AbstractThe effects of bucumolol (BUC), nadolol (NAD) and nifenalol (NIF) on contractile forces and on action potentials (APs) were investigated in isolated guinea pig atrial and papillary muscles, respectively. Log 1/ED40 values for the negative inotropic effects of these drugs were 0.097, 10 and 0.74 mmol/l in this order. BUC (50 mumol/l), NAD (0.5 mmol/l) and NIF (0.2 mmol/l) produced about 60, 20 and 20% reduction of Vmax at 1 Hz. The frequency-dependent reductions at these and higher concentrations were greatest for BUC, intermediate for NAD and least for NIF. These potencies at certain frequencies were, as a whole, consistent with log P-potency relationship established in our previous papers (Harada et al. 1981; Ban et al. 1985). The reductions of Vmax in APs in response to premature stimuli during basic stimuli at the rate of 0.25 or 0.027 Hz decayed exponentially during diastolic intervals (DI). The time constants of these decay process (tau) estimated by linear and nonlinear regression analyses and by eye were 12.2-9.6 s for BUC (50-100 mumol/l) and 2.9-4.8 s for NAD (1-2 mmol/l) and 57-87 ms for NIF (0.2-1 mmol/l). In terms of the molecular weight (MW)-log tau relationship (Ban et al. 1985), these tau values are within the 95% fiducial limit for BUC and NAD and deviated from the lower fiducial limit for NIF. The frequency-dependent reductions of Vmax by these drugs were explained in terms of a function of tau and the intercept Ao. Based on the study made by Cohen et al.(ABSTRACT TRUNCATED AT 250 WORDS)
Naunyn-Schmiedeberg's archives of pharmacology.Naunyn Schmiedebergs Arch Pharmacol.1986 Mar;332(3):297-304.
The effects of bucumolol (BUC), nadolol (NAD) and nifenalol (NIF) on contractile forces and on action potentials (APs) were investigated in isolated guinea pig atrial and papillary muscles, respectively. Log 1/ED40 values for the negative inotropic effects of these drugs were 0.097, 10 and 0.74 mmol
Assessment of beta-blockade and the non-specific effect of bucumolol, a beta-adrenergic blocking agent, on atrioventricular conduction in anesthetized dogs.
Nakayama K, Oshima T, Koike H.AbstractThe effects of the beta-adrenergic blocking agent bucumolol [dl-5-methyl-8-(2-hydroxy-3-t-butylaminoproxy)coumarin] and its optical isomers were compared with those of propranolol and pindolol on the functional refractory period and the conduction time of atrioventricular (A-V) transmission in dogs. In dogs with intact nerves anesthetized with pentobarbital, bucumolol and propranolol (30 micrograms - 1 mg/kg) prolonged both parameters by blockade of background sympathetic nervous tone to A-V conduction. The optical d- and l-isomers of bucumolol depressed A-V conduction almost in parallel with their beta-blocking actions. In dogs with cardiac sympathectomy and bilateral vagotomy, or pretreated with reserpine, the dromotropic activity was lowered and the beta-blocking dose (30 micrograms - 1 mg/kg) of bucumolol and propranolol had less effect on A-V conduction, while larger doses (3-10 mg/kg) produced additional depression of the conduction. Pindolol, on the other hand, had a positive dromotropic action, reflecting its intrinsic stimulatory action. It is concluded that A-V conduction is affected by the existing tone of sympathetic nervous activity and that bucumolol has no beta-stimulant action and depresses A-V conduction by beta-blockade and by a non-specific action.
Archives internationales de pharmacodynamie et de thérapie.Arch Int Pharmacodyn Ther.1981 Nov;254(1):145-56.
The effects of the beta-adrenergic blocking agent bucumolol [dl-5-methyl-8-(2-hydroxy-3-t-butylaminoproxy)coumarin] and its optical isomers were compared with those of propranolol and pindolol on the functional refractory period and the conduction time of atrioventricular (A-V) transmission in dogs.
Enantioselective Distribution of Amino-Alcohols in a Liquid-Liquid Two-Phase System Containing Dialkyl L-Tartrate and Boric acid
阿部 芳廣,庄子 知子,小林 美智,王 菁,浅井 直子,西澤 秀幸
Chemical & pharmaceutical bulletin 43(2), 262-265, 1995-02-15
… Racemic amino-alcohols such as pindolol, propranolol, alprenolol and bucumolol enantiomers exhibited different distribution behaviors in a two-phase system consisting of a chloroform solution of didodecyl L-tartrate and an aqueous solution of boric acid. …
Effects of bucumolol, a β-adrenergic blocking agent, on blood pressure and the renin angiotensin system were studied in spontaneously hypertensive rats (SHR) . The results were compared with those of propranolol at an equipotent does in ...
Racemic amino-alcohols such as pindolol, propranolol, alprenolol and bucumolol enantiomers exhibited different distribution behaviors in a two-phase system consisting of a chloroform solution of didodecyl L-tartrate and an aqueous solution ...