Non invasive in vivo investigation of hepatobiliary structure and function in STII medaka (Oryzias latipes): methodology and applications

Table 7 Volumetric assessment of α-napthylisothiocyanate (ANIT) exposed livers

30 dpf 2.5 μM ANIT, 48 hpd	Volume μm³	% Volume	SA μm²
Intrahepatic Biliary Passageways	11743	0.5%	37818
Vasculature	159187	7.3%	92092
Parenchyma	2023674	92.7%	0
Hepatocellular	2011931	92.2%	0
Liver Corpus	2182861	-	156422
Stack size: 230 × 230 × 89 μm, 1 μm sections, scaling/voxel size 0.45 × 045 × 1 μm, 3D volume analysis ~30% total liver volume
30 dpf 1 μm ANIT, 48 hpd	Volume μm ³	% Volume	SA μm ²
Intrahepatic Biliary Passageways	100354	1.18%	164119
Vasculature	421852	7.92%	207939
Parenchyma	8083460	92.08%
Hepatocellular	7983106.00	100.00%
Liver Corpus	8505312		546491
Stack size: 325 × 325 × 89 μm, 1 μm section, scaling/voxel size 0.64 × 0.64 × 1 μm. ~30% total liver volume
	Mean: 8 – 30 dpf	2.5 μM ANIT 30 dpf	1 μM ANIT 30 dpf
CTRL vs. Treated	% Volume	% Volume	% Volume
Intrahepatic Biliary Passageways	0.97%	0.5%	1.18%
Vasculature	7.51%	7.3%	7.92%
Parenchyma	92.49%	92.7%	92.08%
Hepatocellular	91.52%	92.2%	92.15%
Liver Corpus

Volumetric comparisons between normal and ANIT exposed livers. Indices are summarized in the lower part of Table 7 (see also Table 5). Medaka treated with 1 μM ANIT and analyzed (3D reconstructions, volumetrics) at 30 days exhibited an increase in volume of intrahepatic biliary passageways. Medaka treated with 2.5 μM ANIT and analyzed at 30 days exhibited a decrease in intrahepatic biliary volume. Where biliary volumes were changed in ANIT exposed animals, other indices of vasculature, parenchymal and hepatocellular volume remained relatively well conserved across normal and treated medaka. These results, while from only 2 treated animals, may suggest a choleretic response at low ANIT exposure concentrations, and cholestatic like response at higher aqueous ANIT concentrations. Due to the time consuming nature of 3D reconstructions, only 2 livers of treated animals were reconstructed in full.