دراسة مظهرية مقارنة في الكلية بين الجرذان المختبرية والجرذان البرية مع التركيز على التركيب النسيجي والنسيجي الكيميائي للخلية المحيطة بالقطب والجهاز المجاور للكبيبة

Morphological Comparative Study of the Kidney between Laboratory (Rattus norvegicus) and Wild Rats (Rattus norvegicus) focusing on Histological and Histochemical of (Peripolar Cell and Juxtaglomerular Apparatus)

Abstract
The current study investigated the fundamental histological differences between lab and wild rats kidney, as well as the histological features of specialized cells in renal corpuscles. Understanding the glomerular vascular pole’s physiology and biodiversity was crucial for comprehending crescent development and peripolar regeneration. The current study looked into the primary histological differences between domestic and wild rats as well as the histological characteristics of the specialized cells in renal corpuscles. Two groups of twelve rats each were formed from the two strains of rats utilised in the experimental investigation. Wistar albino rats (Rattus norvegicus) were housed at the animal house/pharmacology college at Kerbala University, while the brown rats (Rattus norvegicus) were captured from agricultural areas and orchards in the Karbala Governorate.
We used Hematoxylin and Eosin Stains for a general histological investigation, Masson trichrome stain for use examined Collagen fibers, Gomori trichrome stain for smooth muscle cells.
The kidneys located behind the peritoneum in the posterior region of the upper abdomen, on each side of the upper lumbar vertebra. And had smooth surface. The right kidney in both species was situated more cranially than left covering by fibrous connective tissue capsule.
In both lab and wild rats had kidneys that resemble dark red and bean shape but more dark in lab rats. However, the two species differ significantly in terms of weight and size. In contrast to their wild counterparts, lab rats typically had larger and heavier kidneys. Furthermore, lab rats’ kidneys were thicker, longer, and wider. Labrats also exhibit a higher ratio when the kidney weight was compared to body weight, suggesting a proportionately larger kidney size.
Renal corpuscles, proximal convoluted tubules, and distal convoluted tubules make up the rat kidney’s cortex. The renal cortex of lab rats was significantly thicker than that of wild rats. The was implies that compared to their wild counterparts, lab rats had a more developed cortical region.
The renal corpuscles in lab rats appear normal and well-structured, while wild rats show more changes, including enlarged glomeruli, increase mesangial cells, and thicken Bowman’s capsules, indicating morphological differences. The Bowman’s capsule had two thin layers: an inner visceral and an outer parietal layer of squamous epithelium. While cellular structure was similar in both rat types, the Bowman’s space was wider in lab rats than in wild rats.
The juxtaglomerular apparatus was positioned at the vascular pole of each glomerulus in the cortex. The nuclei of the juxtaglomerular cells were round and heavily stained with hematoxylin, in wild rats that appear as one cell, large in size, in wall of afferent arterioles. In wild rats, the juxtaglomerular apparatus was considerably changed owing to the number of cells and density of macula densa, whereas in lab rats were simply. The nuclei of macula densa were located closer together and may exhibit more irregularities. When compared to lab rats, where the macula densa cells were grouped adjacently and seem densely stain, wild rats’ macula densa cells were huge and densely packed, making up the majority of the juxtaglomerular apparatus’s total number of cells. Lacis cells in wild rats this cells appear clearly and high in number than lab rats.
The peripolar cell lies adjacent to the visceral and parietal glomerular layers near the Bowman’s capsule. Their outside surface was open to the urine space in a “peripolar” posture. In both lab and wild rats, the peripolar cells that expanded with processes, type of these cells present within them were dendritic peripolar cells. These were one specific type of dendritic cells observed in rats.
In lab rats, their cell bodies were pyramidal, but in wild rats, the shape of peripolar cells bodies they were fusiform shape and spherical shapes. The gap that exists between afferent and efferent arteries contains a number of peripolar cells with extensions extending in opposite ways.
In conclusion, the juxtaglomerular apparatus in wild rats had cellular changes due to adaptation to the environment. The percentage of peripolar cells, were higher in wild rats. There was a difference in shape between wild and labrats. Due to the influence of the environment and the nature of food, which led to an increase in its presence and had a change in shape. It may work as a control gate that controls the glomerular filtration rate.