Rodent Renal Structure Differs among Species

Abstract

ABSTRACT. In the present study, we histologically and morphometrically investigated species differences in renal structure using laboratory rodents (mice, gerbils, hamsters, rats, and guinea pigs). Morphometric parameters were as follows, 1) diameter of the cortical renal corpuscles, 2) diameter of the juxtamedullary renal corpuscles, 3) percentage of the renal corpuscles with a cuboidal parietal layer, 4) number of nuclei in proximal convoluted tubules (PCTs) per unit area of cortex, 5) semi-quantitative score of the periodic acid-Schiff (PAS) -positive granules in PCTs, and 6) semi-quantitative score of the PAS-positive granules in proximal straight tubules (PSTs). Significant species differences were detected for each parameter, and particularly severe differences were observed in the PAS-positive granules of PCTs and PSTs. Granular scores varied among species and sexes. Vacuolar structures that did not stain with PAS or hematoxylin-eosin were observed in the renal proximal tubules. The appearance and localization of these vacuolar structures differed remarkably between species and sexes. KEY WORDS: morphology, morphometry, rodent kidney, sex difference, species specific difference.J. Vet. Med. Sci. 68(5): 439-445, 2006 A thorough understanding of the complex structures of the mammalian kidney provides a basis for comprehending the multitude of functional characteristics of this organ in both healthy and diseased states. The structure of this organ is closely related to its functions including production of urine, regulation of osmolarity, pH, body fluid composition and blood pressure, and metabolism of various substances. Many reports have addressed species-specific differences in mammalian kidneys [1,3,9,10,14,20,25]. In laboratory rodents, glomerular filtration rate (GFR) [10], activities of some dehydrogenases in the macula densa [14], and maxim urine-concentrating capacity [20] were found to differ among species. However, because of a lack of comparative studies, morphological differences in renal structure remain unclear. In the present study, to clarify species differences in renal structure of laboratory rodents, we comparatively investigated the kidneys of mice, gerbils, hamsters, rats, and guinea pigs using a morphometric approach. MATERIALS AND METHODS Animals:Male and female DBA/2CrSlc mice (n=5/each sex), MON/JmsGbsSlc gerbils (n=3/each sex), Slc:Syrian hamsters (n=3/each sex), F344/NSlc rats (n=4/each sex) and Slc:Hartley guinea pigs (n=3/each sex) were used in the present study. All animals were housed in an open system room with a one-way airflow system (temperature 22 ± 1°C; humidity 55 ± 10%; light period 07:00 to 19:00; ventilation 12 cycles/hr), and were given an autoclaved commercial diet (CE-2; Japan CLEA Inc., Tokyo, Japan) and tap water ad libitum. The present study was performed in accordance with the Guidelines for Animal Experimentation of Kagoshima University, Japan. All animals were sacrificed at 90 days of age by exanguination of the carotid arteries under anesthesia using a m...

Modelling normal and nephrotic axial uptake of albumin and other filtered proteins along the proximal tubule

“…Hence, Eqns (8–10) are solved separately for SLN and LLN, and total uptake is computed based upon the SLN‐to‐LNL ratio in mice, taken as 64:36 (Ichii et al . 2006). The computational code is available from the corresponding author upon request.…”

“…We consider both short (SLN) and long (LLN) loop nephrons, which are taken to differ only by the length of their sub-segments S1, S2 and S3. Hence, Eqns (8-10) are solved separately for SLN and LLN, and total uptake is computed based upon the SLN-to-LNL ratio in mice, taken as 64:36 (Ichii et al 2006). The computational code is available from the corresponding author upon request.…”

Species Specific Differences in the Ratio of Short to Long Loop Nephrons in the Kidneys of Laboratory Rodents

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Abstract:The ratio of short to long loop nephrons (SLNs and LLNs, respectively) in laboratory rodents (mice, rats, hamsters, gerbils, and guinea pigs) Recently, we morphometricaly investigated the kidneys of laboratory rodents (mice, rats, hamsters, gerbils and guinea pigs), and identified species-dependent differences of kidney morphology [2]. However, species-dependent differences of the ratio of SLNs to LLNs among these animals remain unclear.

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Comparative Analysis of Hypertensive Tubulopathy in Animal Models of Hypertension and Its Relevance to Human Pathology

“…In Ang II–infused mice, tubular cytoplasmic accumulation of PAS-positive granules and vacuoles in cytoplasm in the tubular epithelium are not considered specific for hypertensive lesions nor are they associated with CPN. 33,48,49 Since in healthy control animals the collagen area occupies only ~0.24%, the enhancement to 1.45% in Ang II–infused mice means a 6-fold increase and is considered quite significant. Similar results were obtained in the majority of studies involving Ang II-infusion 12,13,16,24,50 and TTRhRen mice.…”