A morphometric study on growth of bile canaliculi after partial hepatectomy

19-33 h after partial hepatectomy there is a time-dependent increase of the bile canalicular luminal volume, of the total length of bile canaliculi, and of their non-microvillous, smooth surface, when measured per unit volume of lobular parenchyma. On average the luminal volume fraction is increased by a factor of 2.8, the length per volume by a factor of 1.4, and the density of smooth surface by a factor of 2.0, when compared with sham-operated controls. On the other hand, the volume and surface density of bile canalicular microvilli are only slightly increased after partial hepatectomy. These findings are interpreted as indicating disproportional growth of bile canaliculi which is due predominantly to the formation of new, at first non-microvillous, membrane.