Histological changes of kidney and Salt glands in response to over load salty water in Mallard Ducks (Anas playhrnchos)

Abstract

Present study were carried out on Fifteen adults of the fresh water Mallared ducks, divided into three groups for determinate the histological adaptation of kidneys in absence of salt glands. The results were showed that, the kidneys of birds in group 3were increased in the size (52±0.8cm) in compared to those of control group (40±0.3cm). Histologically, showed marked congestion in renal tubules, glomerular congestion, and thickening of bowman capsule.Thelining cells of proximal and distal convoluted tubules showed enlarged acidophilic cytoplasm and their nuclei were heterochromic. The collecting tubules were lined with low cuboidal cells, most of them showed degeneration, and increased in their acidic mucussecretion. In group 2, the size of kidneys was (42±0.2cm) and in control group was (40±0.1cm), the histological results in this group appeared as that of control group. The salt glands of birds in group 2 showed enlargement of theseglands, each gland consisted of an array of secretory lobules surrounded by vascular capsule. Each lobe was made up of branched secretory tubules radiate from central canal. The secretory tubule lined with simple cuboidal epithelium. The secretory tubules and central canals drain in a main duct. These histological structures showed mild congestion in blood capillaries. The secretory units at the periphery of glandular lobules appeared hypertrophied.Hematological results showed significant increase in levels of the blood urea in birds of group three (24.7± 0.5 mg/dl), while the results of birds in groups two and control were 17.9±0.4 mg/dl and 16.12±0.2 mg/dl respectively. The present study concluded that, the salt glands in marine bird will be rest and non-functional in bird that watered on fresh water and be activated in salt water intake and the kidney can’t play a role of salt gland instead of itsabsence.