Comparison of the Morphometric Features of the Left and Right Horse Kidneys: A Stereological Approach

Abstract

The aims of this study were to determine the total volume of the horse kidney and volume fractions of its functional subcomponents (cortex, medulla, renal pelvis) using stereological methods and investigate any possible difference in the functional subcomponents of the right and left kidneys that may arise from differences in shape. The study was carried out on the kidneys of 5 horses of different breed and sex. The weight of the kidneys was measured by a digital scale, and kidney volume was calculated by Archimedes' principle. Total kidney volume and volume fractions of subcomponents of the right and left kidneys were estimated by the Cavalieri's principle. The weights of the right and left kidneys were 550 ± 25 g and 585 ± 23 g, respectively. The volumes of the right and left kidneys estimated using the Cavalieri method were 542 ± 46 ml and 581 ± 29 ml. The relative organ weight of the kidneys was calculated as 1:330. The densities of the right and left kidneys were determined to be 1.01 and 1.00, respectively. The mean volume fractions of the cortex, medulla and renal pelvis were determined as 55.6, 42.7 and 1.7 in both kidneys. No statistically significant difference existed between morphometric data pertaining to the right and left kidneys (P > 0.05). To determine precisely whether differences in shape cause any difference in the functional subcomponents of the right and left kidneys requires further investigation of differences in the number of microscopically functional unit of the kidney such as renal glomeruli and nephrons.

Cat Kidney Glomeruli and Tubules Evaluated by Design‐Based Stereology

“…The total volume of kidney in cat measured to be about 11.4 cm 3 and the proportional volume of cortex and medulla was determined to be approximately 65.7% and 34.2%, respectively. In the human kidney, the volume fractions of cortex and medulla have been estimated to be 73% and 27% (Hommos et al, ), compared with approximately 54%–57.1% and 41.4%–44.1% in horse (Bolat et al, ), 69.7% and 27.1% in sheep (Pazvant et al, ), 61.4% and 37.6% in rat (Garcia‐Sanz et al, ), and 59.8%–61.8% and 34.7%–36.4% in rabbit (Bolat et al, ). Therefore, the relative volumes of cortex and medulla in the cat kidney were similar to what has been observed in several other species.…”

“…Most stereological investigations on the kidney have been carried out on laboratory animals such as mouse (Arsenault et al, ; Walton et al, ; Nuñez et al, ) and rat (Şimşek et al, ; Khoshvakhti et al, ; Melchioretto et al, ; Seravalli et al, ), and also on other mammals such as nonhuman primates (Gubhaju and Black, ; Batchelder et al, ). However, apart from investigations on the kidney in pig (Cibulskyte et al, ; Karstoft et al, ; Lødrup et al, ,b), sheep (Bains et al, ; Wintour et al, ) and horse (Bolat et al, ), the morphometric features of kidney of other domestic animals have not been thoroughly investigated using stereology.…”

Doppler Ultrasonographic Estimation of Renal Resistive Index in Horse: Comparison Between Left and Right Kidneys

“…The ratio between weight and volume of the kidney is 1:1; accordingly, 1 g of renal weight is equivalent to 1 mL of renal volume. Standing on some authors, further microscopically investigations of renal glomeruli and nephrons are necessary to determine whether differences in shape result in any difference in the functional subcomponents of both kidneys [36].…”

Doppler evaluation of renal resistivity index in healthy conscious horses and donkeys

“…However, using a stereological method the kidneys showed similar weight, density, volume and volume fractions (cortex, medulla, pelvis). Whether there are any microscopical differences in functional subunits is not known [26].…”