Quantitative histochemical study of differentiation of bile canaliculi and liver sinusoids in the liver of human embryos.

The study was performed on the liver tissue of 15 human embryos and foetuses aged 7 to 19 weeks. The combined reaction to dipeptidylpeptidase IV (DPP IV) and alkaline phosphatase (AlP) was performed on cryostat sections. A test grid according to Weibel was used for the evaluation of the DPP IV and AlP-positive areas. During the whole period studied the presence of AlP positive areas prevailed over that of DPP IV positive ones, while the number of areas without activity remained unchanged. The AlP-positive areas vary between 15-29%, the extent of DPP IV positive areas is in the range of 11-18%.