Animal experiment:

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].

RS 17053 hydrochloride is a novel and selective α1A-adrenoceptor antagonist [1].
α1A-adrenoceptor are widely distributed and activated either by epinephrine released from the adrenal medulla or by norepinephrine released from sympathetic nerve terminals. α1A-adrenoceptor mediate a variety of functions, including cardiac stimulation, contraction of smooth muscle, activation of hepatic gluconeogenesis， glycogenolysis, cellular proliferation and apoptosis.
In rat several tissues, RS-17053 had high affinity for the α1A -adrenoceptor and a 30 ~100-fold selectivity over the α1B - and the α1D -adrenoceptor subtypes [1]. RS 17053 had over 100-fold lower affinity for the α1A -adrenoceptor mediating contraction of the rat portal vein (pKB 7.1) and human prostate (pKB 7.1) compared with its affinity for the α1A -adrenoceptor in the rat epididymal vas deferens or the expressed α1A -clone. Therefore, RS 17053 may distinguish between subtypes of the α1A -adrenoceptor in the rat portal vein and human prostate compared with those in the rat epididymal vas deferens or the expressed α1A -clones [2].
References:
[1]. Ford AP, Arredondo NF, Blue DR Jr, et al. RS 17053 (N-[2-(2-cyclopropylmethoxyphenoxy)ethyl]-5-chloro-α,α-dimethyl-1H-indole-3-ethanamine hydrochloride, a selective α1A-adrenoceptor antagonist, displays low affinity for functional α1-adrenoceptors in human prostate: implications for adrenoceptor classification. Mol Pharmacol, 1996, 49(2): 209-215.
[2]. Marshall I, Burt RP, Green GM, et al. Different subtypes of α1A-adrenoceptor mediating contraction of rat epididymal vas deferens, rat hepatic portal vein and human prostate distinguished by the antagonist RS 17053. Br J Pharmaco, 1996, 119(2): 407-415.