Labetalol (AH5158) is an orally active selective α1- and non-selective β-adrenergic receptors competitive antagonist. Labetalol, an anti-hypertensive agent, can be used for the research of cardiovascular disease, such as hypertension in pregnancy[1][2][3].

Labetalol exhibits greater affinity for β-adrenergic sites on guinea pig heart and lung membranes (IC50=0.8 and 4.0 μM respectively) [2].Labetalol has affinity for α-adrenergic binding sites (IC50=15 uM) on rabbit uterine membranes.Labctalol has 19 times greater binding affinity for β binding sites in heart membranca than α binding sites in uterine membranes[2].

Labetalol (10 mg/kg; i.h.) passes the blood-brain barrier, reaching a level of 2.1 ug/g tissue in the 10-day-old rat pups brain 90 min after injection[4].Labetalol (5.0 mg/kg; i.p.) attenuates circulating IL-1β and IL-6 in tailshock stress rats[5].

[1]. Brogden RN, et al. Labetalol: a review of its pharmacology and therapeutic use in hypertension. Drugs. 1978;15(4):251-270.
[2]. Greenslade FC, et al. Labetalol binding to specific alpha- and beta-adrenergic sites in vitro and its antagonism of adrenergic responses in vivo. J Mol Cell Cardiol. 1979 Aug;11(8):803-11.
[3]. Easterling T, et al. Oral antihypertensive regimens (nifedipine retard, labetalol, and methyldopa) for management of severe hypertension in pregnancy: an open-label, randomised controlled trial. Lancet. 2019 Sep 21;394(10203):1011-1021.
[4]. Erdtsieck-Ernste EB, et al. Changes in adrenoceptors and monoamine metabolism in neonatal and adult rat brain after postnatal exposure to the antihypertensive labetalol. Br J Pharmacol. 1992 Jan;105(1):37-44.
[5]. Johnson JD, et al. Catecholamines mediate stress-induced increases in peripheral and central inflammatory cytokines. Neuroscience. 2005;135(4):1295-307.