Capromorelin Tartrate (CP 424391-18) is a potent, orally active growth hormone secretagogue receptor (GHSR) agonist (Ki: 7 nM for hGHS-R1a).

GHS-R1a (human):7 nM (Ki)

Capromorelin在大鼠脑垂体细胞培养中促进GH释放（EC50：3 nM）[1]。

Capromorelin在啮齿动物模型中展现出了增强的肠道吸收能力，并且在药代动力学属性上表现出众，包括在两种动物模型中的高生物利用度（F(rat)=65%，F(dog)=44%）。Capromorelin能够在麻醉状态的大鼠模型中刺激GH释放（ED50: 0.05 mg/kg iv）。接受capromorelin（30 mg/mL）治疗的狗，其食物消耗量显著高于接受安慰剂治疗的狗。所有接受capromorelin治疗的狗体重增加了0.52 kg，这一增加量高于安慰剂组。

Membranes are prepared from HEK293 cells stably transfected with the human GHS-R1a receptor cDNA in the plasmid pcDNA3.1neo. Competition radioligand binding assays are performed in 96-well format with GF/C filters pre-soaked in 0.3% polyethyleneimine. Assays are performed at room temperature for 1 h in duplicate using 50 pM [125I]-ghrelin and 1 μg membrane per well in 50 mM HEPES, pH 7.4, 10 mM MgCl2, 0.2% bovine serum albumin and the following protease inhibitors: 100 μg/mL bacitracin, 100 μg/mL benzamidine, 5 μg/mL aprotinin, 5 μg/mL leupeptin. The membranes are harvested and washed three times with ice-cold ish buffer containing 50 mM HEPES, pH 7.4 and 10 mM MgCl2. IC50 and Ki values are determined using Prism. The Kd of [125I]-ghrelin at membranes expressing human GHS receptors is calculated to be 0.2 nM [1].

The study tested capromorelin flavored oral solution with 30 mg/mL of capromorelin compared to a matched placebo flavored oral solution treatment (which contains all the ingredients of the formulation without capromorelin) administered for 4 days. Dogs are randomized into two groups, with Group 1 receiving placebo (0.1 mL/kg) and Group 2 receiving 3.0 mg/kg. Both groups are treated once a day at approximately 9 AM each day. The first day of dosing is considered Day 0. The placebo and test drug are administered by a syringe placed in the corner of the mouth. The Day 0 weight is used for dose calculations [2].