Polarity of cultured newborn rat skin basal cell layer

Basal cells were prepared from the newborn rat skin epidermis and cultured on a type I collagen-coated filter. This cultured basal cell layer showed an amiloride-sensitive polarity, and the apical surface of the cell layer was more acidic than the basal surface. When the basal cells were cultured with ascorbic acid, a polarity reverse of the cultured cell layer was observed. In this case, synthesized and accumulated type IV collagen was detected on the whole apical surface of the cultured cell layer. An inhibitor of collagen synthesis, cis-hydroxyproline (cis-OH-Pro), suppressed the ascorbic acid-induced polarity reversal. Furthermore, when basal cells were cultured on a type IV collagen-coated filter, the amiloride-sensitive polarity of the cultured cell layer resembled the cultivation on a type I collagen-coated filter. In this case, the polarity was reversed by the addition of ascorbic acid, and cis-OH-Pro suppressed this reversal. Based on these results, we concluded that cultured skin basal cell layer showed an amiloride-sensitive polarity. Moreover, newly synthesized and accumulated type IV collagen was deduced to affect the polarity reversal in the cultured basal cell layer.