Macroscopic, Histomorphological and Histochemical Studies on the Kidneys of Guinea Fowl (Numida meleagris)

Background: Kidneys, the paired organ which essentially plays for excreting nitrogenous wastes, excessive water, inorganic salts and toxic substances produced during the process of body metabolism. Maintenance of osmotic regulation and homeostatic fluid balance of the body has also be performed by kidneys. Each of the kidneys filtrate carried to cloaca by respective ureter from where the urine leaves the body. The present macroscopic, histomorphological and histochemical studies undertaken on the kidneys of Guinea fowl (Numida meleagris) is nothing but the attempt to widen our thrust area for that bird which is nonexistent as on documentation. Methods: The present studies were carried upon 12 pairs of in-vitro kidney samples in Guinea fowl. Gross morphology and morphometrical observations were carried on fresh specimens. Histological studies were carried on fixed samples those were processed for dehydration, clearing, embedding into paraffin and sections of 5-6 mu thickness were obtained. Different staining procedure as to Haematoxylin and Eosin, Silver orcein, Aniline blue and Weigert's staining methods were employed for different histological components. The histochemical and histoenzymic studies were also accomplished with Periodic acid Schiff`s (PAS), Alcian blue methods (pH-2.5) and Gomori's cobalt method for alkaline phosphatase and acid phosphatase. The succinic dehydrogenase enzyme was also estimated on cryostat sections. Result: The observations on kidneys of Guinea fowl were accomplished after macroscopic, histomorphological and histochemical means. This reddish-brown colored paired organ of kidneys was retroperitoneally placed in synsacral fossa and had incomplete division of three parts. The wrapping material of capsule was the dense connective tissue. The outer cortex and inner medulla had different parts of nephrons. Two types of nephrons viz. mammalian type (with Henle loop) and reptilian type (without Henle loop) were observed. Collagen, elastic and reticular fibers were there in different components of the kidney. Histochemically it has determined the secretion of neutral as well as acidic mucopolysaccharide substances. PAS activity was observed at mesangial cells and basement membrane of DCT. The alkaline phosphatase showed the positive activity in capsule, brush border of proximal and distal convoluted tubules. The acid phosphatases were showing intense activity in parietal and visceral layer of renal corpuscles, lumen and basement membrane of PCT. The intense activity of Succinic dehydrogenase showed at PCT, DCT, collecting tubule whereas renal corpuscles showed feeble activity.