Table 4.

Characteristics of the studies evaluating the effect of RA on kidney fibrosis.

Author	Year	Type of animal/cells	Weight of animal/Age	Type of RA	Dose of RA	Effect
Wagner et al.	2000	Wistar rats	180–200 g	ATRA	10 mg/kg per day	+
Morath et al.	2001	Wistar rats	180–200 g	ATRA	10 mg/kg per day	+
Lehrke et al.	2002	Wistar rats	180–200 g	Ro-257386	80 mg/kg per day	+
Oseto et al.	2003	Wistar rats	Twelve-week-old	ATRA	30 mg/kg per day	+
Schaier et al.	2004	Wistar rats	145–150 g	AGN 195183 or AGN 194204	4 mg/kg, 20 mg/kg per day AGN 195183; 0.4 mg/kg,, 2 mg/kg per day AGN 194204	+
Adams et al.	2005	Rats	200–220 g	13-cis-RA	2 mg/kg per day	+
		Macrophages, Fibroblasts	–	13-cis-RA	10 μM	+
Wen et al.	2005	Glomerular mesangial cells	–	9-cis-RA	0.01–1 μM	+
He et al.	2007	Mice	–	ATRA	NA	+
		Podocytes	–	ATRA or 9-cis-RA	0.1–10 μM	+
Iyoda et al.	2007	Mice	–	ATRA	20 mg/kg per day	−
Xu et al.	2010	C57BL/6J × CBA F1 mice	One-week-old	ATRA	6–10.7 mg/kg per day; 12.7–18.8 mg/kg per day, 20.1–27.4 mg/kg per day	+
Liu et al.	2011	Sprague-Dawley rats	250–330 g	ATRA	5 mg/kg per day, 10mg/kg per day	+
Kishimoto et al.	2011	C57BL/B6 mice	25–30 g (Eight-week-old)	ATRA	20 mg/kg	+
Zhong et al.	2012	Mice	Four-week-old	Am580	0.3 mg/kg per day	+
Mallipattu et al.	2012	Podocytes	–	ATRA	1 μM	+
Moulder et al.	2002	Rats	–	ATRA	15 mg/kg per day	+
Zhou et al.	2011, 2012	Wistar rats	180–200 g	ATRA	15 mg/kg per day	+

Note: RA = retinoic acid; ATRA = all-trans retinoic acid; NA = relative data were not available in original paper. Effect +: RA plays a protective role against kidney fibrosis/extracellular matrix accumulation; Effect −: RA plays a negative role in kidney fibrosis/induces the accumulation of extracellular matrix.