RS 17053 hydrochloride

RS 17053 hydrochloride is a potent and selective α1A adrenoceptor antagonist, with a pKi value of 9.1 in native cell membrane and a pA2 value of 9.8 in functional assays.

Signaling Pathways >> GPCR/G Protein >> Adrenergic Receptor

Research Areas >> Metabolic Disease

pKi: 9.1 (α1A adrenoceptor in native cell membrane) pA2: 9.8 (α1A adrenoceptor)[1].

In several tissues from rat and cloned adrenoceptors, RS 17053 hydrochloride displays high affinity for the α1A-adrenoceptor (pKi and pA2 estimates of 9.1-9.9) and a 30-100-fold selectivity over the α1 B and the α1 D-adrenoceptor subtypes (pKi and pA2 estimates of 7.7-7.8). However, in isolated smooth muscle preparations from human LUT tissues, RS 17053 hydrochloride antagonizes responses to NE only at high concentrations. Estimates of affinity (pA2) at α1-adrenoceptors mediating NE-induced contractions are 7.5 in prostatic periurethral longitudinal smooth muscle (compared with 8.6 for prazosin), 6.9 in anterior fibromuscular stroma (prazosin, 8.9), and 7.1 in bladder neck (prazosin, 8.5)[1].

RS 17053 hydrochloride has a rapid onset of action, and a duration of action exceeding 60 min. RS 17053 hydrochloride pretreatment significantly alteres food intake [F(4, 132) 5 6.28, p , 0.0001]. 10 mg/kg RS-17053 significantly suppresses food intake[2].

Rats[2] Adult male rats (n=56 to 8 per group) are pretreated (IP) with either 0, 0.1, 0.5, 2.5, or 10.0 mg/kg RS 17053 hydrochloride or with 2.0 mg/kg of the prototypical α1-Adrenoceptor antagonist prazosin. Five minutes later, each rat was treated (IP) with either 0, 5, 10 or 15 mg/kg PPA. Food and water intakes are recorded for a 30 min period starting 10 min after the treatment injection. Rats pretreated with vehicle and then treated with PPA exhibite a dose-dependent suppression of feeding with a maximal effect evident at the 15 mg/kg dose of PPA. Pretreatment with 2.0 mg/kg prazosin reverses the anorexic activity of PPA[2].

[1]. Ford AP, et al. RS-17053 (N-[2-(2-cyclopropylmethoxyphenoxy)ethyl]-5-chloro-alpha, alpha-dimethyl-1H-indole-3-ethanamine hydrochloride), a selective alpha 1A-adrenoceptor antagonist, displays low affinity for functional alpha 1-adrenoceptors in human prostate: implications for adrenoceptor classification. Mol Pharmacol. 1996 Feb;49(2):209-15.

[2]. Wellman PJ, et al. Effects of the alpha 1a-adrenoceptor antagonist RS-17053 on phenylpropanolamine-induced anorexia in rats. Pharmacol Biochem Behav. 1997 May-Jun;57(1-2):281-4.

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