Effects of the R, R-isomer of labetalol, SCH 19927, in isolated tissues and in spontaneously hypertensive rats during a repeated treatment.

Article Details

Citation

Monopoli A, Bamonte F, Forlani A, Ongini E, Parravicini L

Effects of the R, R-isomer of labetalol, SCH 19927, in isolated tissues and in spontaneously hypertensive rats during a repeated treatment.

Arch Int Pharmacodyn Ther. 1984 Dec;272(2):256-63.

PubMed ID
6151824 [ View in PubMed
]
Abstract

The alpha 1- and beta 1-adrenoceptor blocking activity of the R, R-isomer of labetalol, SCH 19927, was assessed in isolated tissues and compared with that of labetalol. The antihypertensive actions of both compounds were then evaluated during a 10-day dose regimen in spontaneously hypertensive rats (SHR). SCH 19927 produced a competitive alpha 1- and beta 1-blockade in vitro as indicated by the parallel shift to the right of the dose-response curves for norepinephrine and isoprenaline, respectively. SCH 19927 was found 4 times more potent as beta 1-blocker and 6.5 times less potent as alpha 1-blocker than labetalol. In conscious SHR, both SCH 19927 and labetalol produced long-lasting antihypertensive effects during the 10-day period of repeated administration with 10 mg/kg p.o. No tolerance to the antihypertensive activity occurred during the treatment. These findings suggest that SCH 19927 is more potent as a beta-blocker than as an alpha-blocker in isolated tissues and produces an effective antihypertensive activity during a repeated dose regimen.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
LabetalolBeta-1 adrenergic receptorProteinHumans
Yes
Antagonist
Details