# Atrazine-Induced Hepato-Renal Toxicity in Adult Male Xenopus laevis Frogs
## 3 Results
### Histopathology
#### 3.2.2 Kidney Histopathology  
The control group showed normal kidney histology, revealing normal proximal tubules (Figure 4A, black arrow), thick loop of Henle (Th) and distal tubules lined by simple short columnar and simple cuboidal epithelial cells, respectively (Figure 4A, red arrowhead). Collecting tubules with stratified cuboidal epithelial cells (white arrow) were observed. Hematopoietic cells were observed in the inter-tubular space with several red nucleated blood corpuscles (Figure 4A, red arrow). Vacuolized epithelial cells were noted within the tubules of the 0.01 ug/L group (Figure 4B, black arrow). In the 0.01 ug/L and 200 ug/L atrazine-exposed animals, tubular degeneration and loss of the epithelial cell-cell border of the thick loop of Henle were observed (Figure 4B,C, arrowhead). In the 500 ug/L group, the integrity of the thick loop of Henle tubule brush border was disrupted (Figure 4D, arrowhead).  
Figure 4: Representative photomicrographs of histopathologic findings in frog kidneys followingsub-chronic atrazine exposure. (**A**) Control with normal histology of proximal (black arrow), distal (red arrowhead), thick loop of Henle (Th) and collecting tubules (white arrow) and inter-tubular space with nucleated red blood cell (red arrow). (**B**) 0.01 ug/L group with degeneration of thick loop of Henle tubule (Th) and vacuolated tubules (black arrowhead). (**C**) 200 ug/L group with epithelial cell-cell boarder loss (black arrowhead) in thick loop of Henle, eosinophilic deposits (asterisk) inside the lumen of thick loop of Henle tubules (Th). (**D**) 500 ug/L group with loss of epithelial cell apical brush boarder (black arrowhead) and eosinophilic deposits (asterisk) in the proximal tubules. (**E**) Control with normal histology glomerulus (insert) and tubules (arrowhead). (**F**,**G**) 0.01 ug/L and 200 ug/L groups with glomeruli atrophy and necrosis (arrowhead) and pertubular hemorrhaging (**H**). (**H**) In 500 ug/L, mild glomerular atrophy (arrowhead) and dilated tubules (black arrow). (**I-K**) Corpuscle perimeter with proximal tubule epithelium height and thick loop of Henle epithelial height, respectively. * significantly decreased compared to control (_p_ < 0.05; \(p\) < 0.03; \(p\) < 0.01, correspondingly). TLOH: thick loop of Henle. H&E stain, scale bar in A to D = 38 \(\upmu\)m (40\(\times\) magnification). Scale bar in E to G = 240 \(\upmu\)m (10\(\times\) magnification). Values are mean \(\pm\) SD (_n_ = 10).  
The cortex of the control group showed normal renal corpuscles (Figure 4E, insert), but degeneration of the renal corpuscles, glomerular atrophy (Figure 4F-H, black arrowhead), dilation of tubular lumen in the 500 \(\upmu\)g/L group (Figure 4H, black arrow) and vacuolized epithelial cells were noted within the tubule of the 200 ug/L group (Figure 4B, black arrow). Furthermore, there was shrinking of some tubules with eosinophilic material infiltration (Figure 4C,D, asterisk) and mild peritubular hemorrhaging (H) in the 0.01 ug/L and 200 ug/L groups (Figure 4F,G). The corpuscle perimeter and TLOH epithelial height were significantly reduced in the 500 ug/L group, while the proximal epithelium height and TLOH were significantly reduced in the 200 \(\upmu\)g/L groups (Figure 4I-K). The 500 ug/L group significantly decreased in corpuscle perimeter compared to the control (Figure 4I, \(p\) < 0.03). The epithelium height of proximal tubules in the 200 ug/L group and thick loop of the Henle tubules in the 200 \(\upmu\)g/L and 500 \(\upmu\)g/L groups significantly decreased (Figure 4J,K, \(p\) < 0.03 and \(p\) < 0.01, correspondingly) relative to the control group.