Cat Kidney Glomeruli and Tubules Evaluated by Design‐Based Stereology

Abstract

Renal function is related to its structure and three‐dimensional structural parameters correlate better with the kidney function than two‐dimensional structural parameters. Stereology is the current gold‐standard technique for the morphometrical evaluation of kidney structures. This study describes morphometric features of the kidney of the cat using design‐based stereological techniques aimed to introduce the cat as a translational model in nephrology and provide basic findings for diagnosis and treatment of kidney diseases in this species. Left kidneys of four cats were included in the present study. The kidney volume, volume fraction of cortex and medulla, glomerular volume, glomerular mean volume, glomerular number, and proximal convoluted tubule (PCT) and distal convoluted tubule (DCT) length were estimated. The kidney volume was estimated to 11.4 ± 1.3 cm3. The volume fraction of cortex and medulla was 65.6 ± 2% and 34.2 ± 2%, respectively. The total number of glomeruli was estimated to be 186 ± 11 × 103 using the physical disector/fractionator method. The mean glomerular volume was estimated to be 1.54 ± 0.06 × 106 μm3 and the glomerular volume was covering 2.13 ± 0.34% of the whole kidney. The total length of PCT and DCT was estimated to be 2.26 ± 0.48 km and 505 ± 43 m, respectively. Our data might contribute to the knowledge of kidneys in mammals and provide a comparison with available data on human and other mammals. Anat Rec, 302:1846–1854, 2019. © 2019 American Association for Anatomy

Stereological analysis of metanephros from domestic cat (Felis catus, Linnaeus 1798) embryos and fetus

“…Even though the number of renal corpuscles from groups 2 and 3 was not statistically different, the metanephros total volume significantly increased from groups 2 to 3 with an average of 0.072cm 3 to 0.201cm 3 , respectively. According to Sadeghinezhad and Nyengaard (2019), the total kidney volume of adult cats was 11.4cm³ which corroborates with the evolution of our research metanephros even after birth, since it is a volume value greater than found in foetuses.…”

“…Consequently, the cortical region in metanephros from groups 2 to 3 decreased from 74% to 63%. In the studies by Sadeghinezhad and Nyengaard (2019), the volume of cortical and medullary layers of adult cats was 65.7% and 34.2%, respectively. These values are close to and higher than the values in group 3 of our research, where we have already found the metanephros at a stage closer to the morphology of an adult cat kidney, but still developing due to incomplete nephrogenesis.…”

“…The total kidney volume of these cats was 11.4cm³ (Sadeghinezhad & Nyengaard, 2019). These studies are critical for nephrology because changes in renal cortex volume may be suggestive of chronic kidney disease and characterize a prognosis of the disease (Woodard et al, 2015).…”

“…In this regard, a number of studies have emerged to investigate the morphological and morphometric parameters of the kidney, ranging from experimental animals such as rats (Melchioretto et al, 2016) to monkeys (Batchelder et al, 2013), cats (Sadeghinezhad & Nyengaard, 2019) and humans (Daković-Bjelaković et al, 2005;Vlajković et al, 2005). These studies include general aspects of this organ such as growth, quantification of its structures and embryonic development that aid the future medical practice.…”

Morphometric study of the testis in sheep embryos using unbiased design‐based stereology

“…The development of the sheep fetal testes was examined using design-based stereological methods, which allow to obtain accurate, reliable and unbiased quantifications of whole anatomical structures, including the testes (Herrera-Alarcón et al, 2007;Malas et al, 2001;Sadeghinezhad et al, 2020;Sadeghinezhad & Nyengaard, 2019;De Silva et al, 2021).…”