# Atrazine-Induced Hepato-Renal Toxicity in Adult Male Xenopus laevis Frogs
## 3 Results
### Histopathology  
#### 3.2.1 Liver Histopathology  
The liver parenchyma revealed a normal microanatomy in the control group with radiating anastomosing cords of hepatocyte (arising from the central veins (Cv) (Figure 2A)) having one or two pale basophilic rounded nuclei and scanty cytoplasm (Figure 2I, red arrow). Between hepatic cords, narrow irregular hepatic sinusoids containing nucleated red blood cells were observed (Figure 2I, black arrow). At the portal triad, branches of the hepatic artery, hepatic portal vein and bile duct lined by simple cuboidal epithelium (Figure 2A, circled) and some melanomas were observed (Figure 2A, red arrow). Figure 2: Cont. In the atrazine-exposed groups, the 200 \(\upmu\)g/L atrazine-exposed group revealed a dilated sinusoid (Figure 2C, black arrows), while in the 500 \(\upmu\)g/L sinusoidal congestion with blood numerous haematopoietic cells were present (Figure 2D, insert), and infiltrating inflammatory cells were observed obscuring the liver tissues (Figure 2H). Parenchyma necrotic areas were observed in the 500 \(\upmu\)g/L group (Figure 2C, circled), and portal inflammation was observed in all atrazine-exposed groups (Figure 2D-F). Hepatocyte cord disarrangement was observed in the 0.01 \(\upmu\)g/L (Figure 2J) and 500 \(\upmu\)g/L (Figure 2L) groups. Hepatocyte vacuolation was also observed in the 0.01 \(\upmu\)g/L, 200 \(\upmu\)g/L and 500 \(\upmu\)g/L atrazine (Figure 2J-L, black arrows). Additionally, ATZ exposure of 200 \(\upmu\)g/L and 500 \(\upmu\)g/L significantly increased hepatocyte width (\(p<0.0003\)) compared to the control (Figure 2). Collagen tissue was increased in all the atrazine-treated groups priortally (Figure 3B-D: red arrows) and sinusoids (Figure 3F-H: red arrows) but not significantly increased relative to the control group (Figure 3J,J; \(p>0.050\)). There was no collagen deposition observed within the hepatic lobules. Figure 2: Photomicrographs of liver histopathology of frogs exposed to atrazine. (**A**) Control group with normal histology, central vein (Cv), portal triad (circle) and melanomacrophages (red arrow). (**B**) 0.01 \(\upmu\)g/L group with clogged central vein (Cv). (**C**) 200 \(\upmu\)g/L group with dilated sinusoids (black arrow). (**D**) 500 \(\upmu\)g/L group with clogged central vein (Cv), sinusoidal congestion (insert) and portal inflammation (red arrow). (**E**) 0.01 \(\upmu\)g/L group with portal inflammation (red arrow). (**F**) 200 \(\upmu\)g/L group with portal inflammation (red arrow). (**G**) 500 \(\upmu\)g/L group with parenchymal (circle) and central vein (Cv) necrosis. (**H**) 500 \(\upmu\)g/L group with abundance of inflammatory cells. (**I**) Control group with normal hepatocyte histology (red arrow) alternating cords and sinusoid arrangement (insert) with nucleated red blood cells (black arrow). (**J**) 0.01 \(\upmu\)g/L group with absence of normal hepatic cord arrangement (insert) and vacuolated hepatocytes (black arrow). (**K**) 200 \(\upmu\)g/L group with highest observed hypertrophy with some vacuolation (black arrow). (**L**) 500 \(\upmu\)g/L group with absence of hepatic cord arrangement and highly vacuolated hepatocytes (black arrows). (**M**) hepatocyte width with significantly increased * in comparison to control (\(p=0.003\)). Values expressed as mean \(\pm\) SD (\(n=10\)). H&E stain. Scale bar in A to H = 240 \(\upmu\)m (10\(\times\) magnification). Scale bar in I to L = 38 \(\upmu\)m (40\(\times\) magnification). Figure 3: Photomicrographs of connective tissue profile in atrazine-exposed groups. (**A**) Normal connective tissue profile in control group. In (**B–D**), 0.01 \(\mu\)g/L, 200 \(\mu\)g/L and 500 \(\mu\)g/L groups, respectively, peri-portal fibrosis (red arrow). (**E**) Control group with normal connective tissue content and absence of peri-sinusoidal fibrosis. In (**F–H**), 0.01 \(\mu\)g/L, 200 \(\mu\)g/L and 500 \(\mu\)g/L groups, correspondingly, peri-sinusoidal fibrosis (red arrow).