Figure 6: Precursors of the aldosterone synthesis did not stimulate development of SBA-labeled tubules. Histochemistry on cryosections showed that administration of (a) cholesterol lacked tubulogenic activity, while application of (b) pregnenolone, (c) progesterone and (d) 11-deoxycorticosterone produced SBA-labeled cell islets. (e) Administration of corticosterone induced numerous SBA-labeled cell clusters. (f) Use of aldosterone resulted in numerous SBAlabeled tubules exhibiting a distinct lumen (arrow) and a clearly recognizable basal lamina (asterisk) after 13 days of culture.