Graham R M, Oates H F, Weber M A, Stokes G S
Arch Int Pharmacodyn Ther. 1976 Feb;219(2):205-10.
The beta-adrenergic blocking agent, timolol, administered to resting rabbits as an i.v. bolus (0.125 mg/kg) sustained by a 2-hr infusion at 0.0625 mg/kg/hr, caused significant depression of plasma renin activity (PRA) to 49% of the control level. Significant correlations emerged between the fall in mean blood pressure and changes in both heart rate and PRA. Timolol also antagonized isoprenaline-induced renin release. In anaesthetized normal rats, timolol (0.2 mg/kg i.p.) suppressed mean plasma renin concentration (PRC) to 16% of the pre-treatment value. Furthermore, the mean PRC of normal rats, bled immediately after decapitation, to avoid stimulating renin secretion, was reduced by 55% one hr after i.p. injection of timolol. The potency of timolol in this respect was 8 times that of dl-propranolol. Thus, in rabbits and rats, timolol effectively depresses both basal and stimulated plasma renin levels.
静脉注射给予静息状态的家兔β-肾上腺素能阻滞剂噻吗洛尔（0.125mg/kg），随后以0.0625mg/kg/小时的速度持续输注2小时，可使血浆肾素活性（PRA）显著降低至对照水平的49%。平均血压下降与心率和PRA变化之间出现显著相关性。噻吗洛尔还拮抗异丙肾上腺素诱导的肾素释放。在麻醉的正常大鼠中，噻吗洛尔（0.2mg/kg腹腔注射）可将平均血浆肾素浓度（PRC）抑制至治疗前值的16%。此外，为避免刺激肾素分泌，正常大鼠断头后立即采血，腹腔注射噻吗洛尔1小时后，平均PRC降低了55%。噻吗洛尔在这方面的效力是消旋普萘洛尔的8倍。因此，在兔和大鼠中，噻吗洛尔可有效降低基础和刺激状态下的血浆肾素水平。
