连续外用维A酸皮肤刺激反应中维A酸受体mRNA的表达

目的研究小鼠皮肤中维A酸受体mRNA表达水平在连续外用维A酸引起皮肤刺激反应发生中的变化规律。方法连续外用0．1％维A酸和基质，应用RT—PCR方法检测Balb／C小鼠皮肤中维A酸受体（RARα、RARγ、RXRα）mRNA的表达水平。结果外用0．1％RA霜，皮肤中RARα mRNA表达水平6d时升高，12d时降至正常，直至24d，一直维持在正常水平。而RARγ、RXRαmRNA表达水平在用药期间未见改变。RA霜基质对这三种受体mRNA的表达没有影响。结论在Balb／C小鼠，连续外用0．1％RA霜，皮肤中RARαmRNA表达水平呈现“上升-高峰-下降”的一过性规律，这与外用RA霜引起的一过性皮肤刺激反应规律相同。外用RA霜引起的一过性皮肤刺激反应可能是由RARd介导的RA霜作用。

The expressions of retinoic acid receptors in the skin irritation induced by topical retinoic acid

Objective To investigate the variation regularity of the expressions of retinoic acid receptors at mRNA level in the skin irritation induced by topical retinoic acid. Methods After 0.1% RA cream and its vehicle were applied respectively on the skin of the BALB/C mice once a day for 24 days, the RT-PCR was used to make semi-quantitive analysis of the mRNA expressions of refinoie acid receptors （RARα,RARγ,RXRα）. Results The mRNA expression of RARa increased 6 days after applications of the 0.1%RA cream （P〈0.05）, then returned to normal on the twelfth day and retained till the twenty-fourth day. No changes were found in the expressions of RARγmRNA and RXRa mRNA. No influences on the mRNA expressions of the three receptors were observed in the control group. Conclusion When 0.1%RA is continuously applied, the mRNA expression of RARαin the skin of the BALB/C mice exhibits a transient regularity of ＂increase-climax-decrease＂, which resembles the transient regularity of skin irritation induced by topical 0.1%RA cream. The skin irritation induced by topical RA cream is, at least, a particular property of the RA associated with the RARα.