Fish kidney histopathology

Eve Fisher

200509792

The Kidney

• The kidney has hematopoietic, reticuloendothelial, endocrine and excretory functions

• Located in the dorsal section of the fish, below the spine

• Dark brown,red or black organ extending the length of the body cavity

• Divided into anterior kidney; responsible for hematopoietic functions, and the posterior; excretory, kidney

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The Kidney

• Renal tissues may be exposed to great concentrations of toxins through the receiving of large quantities of blood

• Urine produced serves as a major route for the excretion of many xenobiotics

Why the Kidney?

• Pathological changes associated with kidney:– Dilation or inflammation of glomerular blood capillaries– Thickening of capillary walls– Destruction or fibrosis of the glomerulus– Capillary sclerosis– Abnormal proliferation of epithelial cells in bowman capsule– Cloudy swelling of epithelial cells of renal tubules– Hyaline droplet degeneration of renal tubule epithelial cells– Necrosis of epithelial cells and glycogen infiltration of

tubular epithelium(Dyk, 2006)

• However, lack of biomarkers

Clarias gariepinus

• Kidney: Dark red in colour• Consists of a thin posterior part expanding laterally

towards the anterior region• Posterior portion consists of nephrons within a

surrounding matrix of hematopoietic tissue• The glomerulus consists of a cluster of blood

capillaries preserved with red blood cells, capillary endothelial cells and mesangial cells

• The Bowmans capsule consists of an inner visceral epithelium of podocytes and an outer parietal layer of squamous epithelium supported by a basement membrane

• Bowmans space observed to be large in C.gariepinus species (Dyk, 2006)

C. gariepinus

• Proximal tubule: columnar to cuboidal epithelium

• Large central and spherical nucleus

• Distinct brush border

• Distal tubules are visibly smaller

http://en.wikipedia.org/wiki/Squamous_epithelium

Normal view of kidney

Reversible changes

•Due to an intracellular accumulation of water•Characterized by clear vacuolar changes in cytoplasm

Types of changes• Renal tubules• Osmic diuresis by

mannitol• Hyper-osmotic substance

given to increase diuresis.• Substance accumulated in

cytoplasmic vacuole in proximal tubules.

• Increase amount of water.• Appears vacuolated and

clear

Types of changes

•Coagulation necrosis of the kidney.•Necrotic cells have no nuclei.•Remaining cytoplasm is red.•Eosinophilic.

Nephrocalinosis

•Accumulation of calcium phosphate•In kidney tubules•Due to high CO2 levels in water and imbalance of Mg2+ and Ca2+•Cause accretation growth due to dilation and destruction of tubular epithelium

Bacterial Kidney Disease

• Chronic Granulomatous inflammation of Kidney

• Multifocal encapsulated granulomas to diffuse granulomas with poorly defined borders

• Macrophages containing bacteria

• Focal necrois and glomerular edema

Enteric Redmouth

• Vascular changes: Conjestion and Hemorrhage

• Focal nerosis of hematopoeitic tissue

Vibriosis

• Acute systemic

• Large colonies of bacteria

• Tissue necrosis

• Hemorrhage, conjestion,leukocyte infiltration

• Necrosis and edema of hematopoeitic tissue

Infectious hematopoietic necrosis

• Severe, diffuse degeneration and necrosis of hematopoietic tissues

• Karryorrhectic nuclei

• Widespread hemorrhage in kidney

• Kidney tubules intact

Proliferative kidney Disease

• Poorly understood protozoan

• Darkening of body colour

• Distended abdomen

• Pale gills indicating anemia

• Pronounced lateral body swelling

• Enlargement of kidney and spleen

• Kidney may be grayish throughout or mottled

Cont. Of Proliferative Kidney Disease

• In severe cases may appear folded

• Imprints of affected kidney stained with Leishman-Giemsa

• Must be able to distinguish trophozoites from host macrophages

Histopathology of Kidney disease in Fish (Wood & Yasutake;1956) Case

Study 1• One of the first histopathlogic studies

undertaken to understand kidney disease

• Fish showing lesions from the East and West coast of USA were chosen for study

• Found impaired renal function, chronic granulomas, fibrotic lesions and giant cells

• First affected: hematopoeitic tissue

• As disease progressed: posterior kidney affected, outstripped vascular supply, terminated in necrosis and suppuration.

Cont. Case study 1

• Salmon exhibit more acute symptoms than trout: Salmon more severly affected

• Edema in tissues resulting from damaged circulatory system

Case Study 2:

• In a study done by Cengiz (2006) it was found that the exposure of fish to Deltamethin resulted in:– degeneration of the epithelial cells of the renal

tubule,– pycnotic nuclei in the hematopoietic tissue

and – dilation of the glomerular capillaries

Cont. Case Study 2

• At higher concentrations– Dilation of glomerular capillaries– Pycnotic nuclei in hematopoeitic tissue– Degeneration of the epithelial cells of the

renal tubules with hypertrophied cells– Narrowing of tubular lumen

•

Cont. Case study 2

• After exposure at this concentration for a longer period of time, the following could be observed– Degeneration of epithelial cells of renal tubules– Pycnotic nuclei in hematopoeitic tissue– Intracytoplasmic vacuoles in epithelial cells of renal

tubules with hypertrophied cells– Narrowing of tubular lumen and– Degeneration of glomerulus

• In a study done by Teh et al (1997) it was found that tissue alterations took place at the tubular epithelium and glomerulus upon exposure to pesticides

Cont Case study 2:

• Renal lesions are expected to be good indicators of environmental pollution

• Dilation of lumina of kidney tubules, necrosis of tubules, shrinage of the glomerular tuft, and vacuolation blood cells in glomerular tuft upon fish exposure to chlorpyrifos has been reported by Srivastava et al (1990)

Abnormal Kidney case study 2

References

• Dyk, A qualitative and quantitative assessment of the normal histology of the selected target organs of Clarias gariepinus and Oreochromis mossambicus

• Fish histology and Histopathology study guide, 2009• Fish histopathology slides, 2009• Wood & Yasutake, 1956, Histopathology of Kidney

Disease in Fish, American Journal of Pathology 32,4,pp.845-857

• Cengiz, 2006, Gill and Kidney histopathology in freshwater fish Cyprinus carpio after acute exposure to deltamethrin, Environmental Toxicology and pharmacology 22, pp. 200-204

Cont. Of References

• http://www.infovisual.info/02/033_en.html• www.pskf.ca/sd/images/dcp_4979.jpg• http://en.wikipedia.org/wiki/Podocyte• http://en.wikipedia.org/wiki/Squamous_epithelium• aquaticpath.umd.edu/apg/images/pknormal.jpg