Effects of retinoic acid exposure in utero on mouse vibrissal follicle development

It is known that topical all-trans-retinoic acid (RA) modulates growth and differentiation of skin and its cutaneous appendages. To examine whether a pre-natal exposure to a potentially non-teratogenic dosage of all-trans-PA had any effect on vibrissal follicle development, the histologic and immuno histochemical responses to RA during its morphogenesis in NMRI mouse were i nvestigated. After a single oral dose of 30 mg/kg body weight of all-trans- RA on day 11.5 of gestation, no fetal malformations were detected and the h istological features and the distribution of keratin (K) proteins in compar able stages of vibrissal development were similar for the untreated, vehicl e-treated and RA-treated mice. The absence of teratogenic response and of a dverse effects on the vibrissae under the experimental conditions indicates that this protocol may be useful for investigation of the effects of pre-n atal exposure to RA on the post-natal development of experimental tumours i n the mouse skin.