Description:
IC50 Value:  1.2 ±0.4 mM (Inhibition of adenylyl cyclase elicited by 0.1 microM Ang II) [2]
PD 123319 is a potent, selective, non-peptide angiotensin AT2 receptor antagonist. IC50 values are 34 and 210 nM in rat adrenal tissue and brain respectively.
in vitro: Neither the AT1 antagonist losartan nor the AT2 antagonist PD 123319 exhibited significant competition for [125I]angiotensin-(1-7) binding to endothelial cells isolated from bovine aorta, in agreement with the absence of detectable mRNAs encoding typical angiotensin receptor subtypes 1 or 2 (AT1 or AT2) [1]. In radioligand binding competition experiments, approximately 25% of the specific binding sites labeled by 125I-[Sar1]Ang II were inhibited by low concentrations of PD 123319 (0.1 to 10 nM), whereas the AT2 antagonist CGP 42112A was inactive at concentrations less than 0.1 microM [2].
in vivo:  PD 123319 did not influence baseline CBF, but resulted in a minor BP decrease (10 control and 10 treated rats) [3].  Sixteen normal subjects aged 29.9+/-13.8 years (range 18-30 years) received an intravenous infusion of PD 123319 (10 mcg/minute for 5 minutes) and placebo, separated by one week. Haemodynamics (cardiac index, stroke index and systemic vascular resistance) were measured non-invasively using a BioZ.com thoracic impedance detection system. Blood pressure was measured from an arm cuff using oscillometry [4].
Toxicity: Losartan and PD-123319 each increased vascular renin distribution in both kidneys. Late losartan treatment had no effect on any of the parameters in either kidney, and PD-123319 had no effect on either kidney [5].
Clinical trial: N/A