RESUMO

Mammals that live in arid and semi-arid environments in South America present physiological mechanisms that enable them to conserve water. Body water is lost through the kidneys, lungs, skin, and intestines. Regarding renal adaptation for water conservation, several indices have been used to estimate the capacity of the kidneys to produce a maximum urine concentration. Most studies were conducted at an inter-specific level, with only few performed at the intraspecific level. In this work, we compare renal function and morphology among five populations of Southern mountain cavy, Microcavia australis, present along an aridity gradient. We hypothesized that individuals from drier zones would present morphological and functional renal modifications that imply a greater capability to conserve body water. These features were studied considering the classical indices (RMT, PMT, PMA, and RMA) and three new indices that consider area measurements; the latter showed to be more adequate to reflect intraspecific differences. Our results suggest that the morphological modifications of kidneys, that is, the greater areas of renal inner medulla, would be related to the aridity gradient where populations of Southern mountain cavy occur.

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We studied the renal morphology of 16 species of passerines to assess whether the composition of the diet of birds have been paralleled by differences in the characteristics of the kidneys. We determined the number and length of the medullary cones and the percentage of renal medulla in birds with contrasting dietary habits and then correlated these features with the percentage of nitrogen and proportion of invertebrates in the diet. To examine the correlation between kidney and diet variables, we first used standard correlation and least square regression, and correlation and regression on phylogenetically independent data. We found that the mass of the medullary portion of the kidney, and the medullary cone length were negatively correlated with the percentage of invertebrates present in the diet. We hypothesized that the further development of the renal medulla observed in granivorous birds may be correlated with the small amount of water present in the seeds. Our results suggest that the availability of water in different foods is probably one of the main factors that have led to structural and probably functional changes of the kidney in the studied species.

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A utilização de técnicas ultrassonográficas na área de Medicina Veterinária está cada vez mais presente e a capacitação nesta área tornou-se indispensável para o clínico, auxiliando-o na obtenção de informações rápidas e valiosas das afecções patológicas que podem acometer os animais. O exame ultrassonográfico renal revelou-se de grande importância neste âmbito, com o objetivo de avaliar e mensurar os parâmetros morfométricos renais normais de fêmeas caprinas (Capra hircus). Por meio de técnicas ultrassonográficas procedeu-se o estudo de 30 fêmeas da raça Saanen, divididas em três grupos: fêmeas com idade inferior a 6 meses (3,0±1,0 meses), de 6-18 meses (9,0±4,3 meses) e com idade superior a 18 meses (46,3±17,4 meses). Realizaram-se imagens dos rins, em secções longitudinais, medidas de comprimento e largura e, em secções transversais, medidas de altura (ou espessura). Com estes valores calcularam-se volumes renais, corticais e medulares, além da relação cortico-medular. Com relação ao comprimento renal os grupos com idade inferior a 6 meses, de 6-18 meses e com idade superior a 18 meses obtiveram média e desvio padrão de 4,20±0,36cm, 5,56±0,40cm e 6,77±0,64cm, respectivamente. Tratando-se do volume renal, estes grupos apresentaram média e desvio padrão de 17,02±3,99cm³, 19,99±5,86cm³; e, 41,23±13,05cm³. Comparou-se a equivalência métrica das médias entre os dois rins de forma que os parâmetros volumétricos e lineares renais com diferença entre si são comprimento renal, volume renal e volume cortical para o grupo de fêmeas com idade de 6-18 meses, e comprimento renal e comprimento medular para o grupo com idade superior a 18 meses. Entre diferentes grupos observou-se que somente o comprimento medular esquerdo apresentou média equivalente em todos os grupos, ou seja, entre o grupo com idade inferior a 6 meses e o grupo com idade de 6-18 meses e, entre este último e o grupo com idade superior a 18 meses. Os resultados mostraram correlações diretas e positivas entre peso corporal e idade com os parâmetros lineares e volumétricos, a relação cortico-medular esquerda foi a única que apresentou correlação significativa com o peso (r= -0,365; P = 0,047). Para aqueles parâmetros que apresentaram correlação significativa foi realizada análise de regressão, obtendo-se a linha de melhor ajuste das variáveis.(AU)

The veterinary ultrasonographic techniques have increased in the veterinary doctor's daily work, therefore training and knowing how to use ultrasound equipment have become needful to the animals healthcare professionals. It's important remember that ultrasound equipment makes possible getting valuable pathological data from animals' health. In this background, the renal ultrasonographic test has gotten an important place and, nowadays, it is possible measure with accuracy the caprine renal morphometrics parameters (Capra hircus). Through ultrasonographic techniques, it has done a stocktaking with three groups of normal goats: older than 18 months (46.3±17.4 months), younger than 6 months (3.0±1.0 months) and age between 6 and 18 months (9.0 4.3 months), totalizing 30 samples of the female Saanen kind. In longitudinal section of the kidneys, measured the length and breadth and, in transverse section, measured the height (or thickness). The values obtained calculated the renal, cortical and medullary volumes, besides corticomedullary correlation. The renal length of the groups younger than 6 months, age between 6 and 18 months and older than 18 months had mean and standard deviation of 4.20±0.36cm; 5.56±0,40cm; and, 6.77±0.64cm, respectively. To the renal volume theses groups had mean and standard deviation of 17.02±3.99cm³; 19.99±5.86cm³; and, 41.23±13.05cm³. It was compared the metrical equivalence of the mean between the two kidneys, to the group with age between 6 and 18 months the parameters showed difference were renal length, renal volume and cortical volume, in other hand to the group older than 18 months it was renal length and medullar length. Comparing different groups was noted that only the left medullar length had equivalent mean in all the groups, it means, the group younger than 6 months, older than 18 months and from 6 to 18 months of age. The results showed direct and positive correlation between corporal weight and age with the linear and volumetric parameters The left corticomedullary correlation was the only of its kind to exhibit significant correlation with the weight (r= -0.365; P value 0.047). The parameters with significant correlation had the regression analysis done, obtained the better line of adjust of the variables.(AU)

Assuntos

RESUMO

A utilização de técnicas ultrassonográficas na área de Medicina Veterinária está cada vez mais presente e a capacitação nesta área tornou-se indispensável para o clínico, auxiliando-o na obtenção de informações rápidas e valiosas das afecções patológicas que podem acometer os animais. O exame ultrassonográfico renal revelou-se de grande importância neste âmbito, com o objetivo de avaliar e mensurar os parâmetros morfométricos renais normais de fêmeas caprinas (Capra hircus). Por meio de técnicas ultrassonográficas procedeu-se o estudo de 30 fêmeas da raça Saanen, divididas em três grupos: fêmeas com idade inferior a 6 meses (3,0±1,0 meses), de 6-18 meses (9,0±4,3 meses) e com idade superior a 18 meses (46,3±17,4 meses). Realizaram-se imagens dos rins, em secções longitudinais, medidas de comprimento e largura e, em secções transversais, medidas de altura (ou espessura). Com estes valores calcularam-se volumes renais, corticais e medulares, além da relação cortico-medular. Com relação ao comprimento renal os grupos com idade inferior a 6 meses, de 6-18 meses e com idade superior a 18 meses obtiveram média e desvio padrão de 4,20±0,36cm, 5,56±0,40cm e 6,77±0,64cm, respectivamente. Tratando-se do volume renal, estes grupos apresentaram média e desvio padrão de 17,02±3,99cm³, 19,99±5,86cm³; e, 41,23±13,05cm³. Comparou-se a equivalência métrica das médias entre os dois rins de forma que os parâmetros volumétricos e lineares renais com diferença entre si são comprimento renal, volume renal e volume cortical para o grupo de fêmeas com idade de 6-18 meses, e comprimento renal e comprimento medular para o grupo com idade superior a 18 meses. Entre diferentes grupos observou-se que somente o comprimento medular esquerdo apresentou média equivalente em todos os grupos, ou seja, entre o grupo com idade inferior a 6 meses e o grupo com idade de 6-18 meses e, entre este último e o grupo com idade superior a 18 meses. Os resultados mostraram correlações diretas e positivas entre peso corporal e idade com os parâmetros lineares e volumétricos, a relação cortico-medular esquerda foi a única que apresentou correlação significativa com o peso (r= -0,365; P = 0,047). Para aqueles parâmetros que apresentaram correlação significativa foi realizada análise de regressão, obtendo-se a linha de melhor ajuste das variáveis.

The veterinary ultrasonographic techniques have increased in the veterinary doctor's daily work, therefore training and knowing how to use ultrasound equipment have become needful to the animals healthcare professionals. It's important remember that ultrasound equipment makes possible getting valuable pathological data from animals' health. In this background, the renal ultrasonographic test has gotten an important place and, nowadays, it is possible measure with accuracy the caprine renal morphometrics parameters (Capra hircus). Through ultrasonographic techniques, it has done a stocktaking with three groups of normal goats: older than 18 months (46.3±17.4 months), younger than 6 months (3.0±1.0 months) and age between 6 and 18 months (9.0 4.3 months), totalizing 30 samples of the female Saanen kind. In longitudinal section of the kidneys, measured the length and breadth and, in transverse section, measured the height (or thickness). The values obtained calculated the renal, cortical and medullary volumes, besides corticomedullary correlation. The renal length of the groups younger than 6 months, age between 6 and 18 months and older than 18 months had mean and standard deviation of 4.20±0.36cm; 5.56±0,40cm; and, 6.77±0.64cm, respectively. To the renal volume theses groups had mean and standard deviation of 17.02±3.99cm³; 19.99±5.86cm³; and, 41.23±13.05cm³. It was compared the metrical equivalence of the mean between the two kidneys, to the group with age between 6 and 18 months the parameters showed difference were renal length, renal volume and cortical volume, in other hand to the group older than 18 months it was renal length and medullar length. Comparing different groups was noted that only the left medullar length had equivalent mean in all the groups, it means, the group younger than 6 months, older than 18 months and from 6 to 18 months of age. The results showed direct and positive correlation between corporal weight and age with the linear and volumetric parameters The left corticomedullary correlation was the only of its kind to exhibit significant correlation with the weight (r= -0.365; P value 0.047). The parameters with significant correlation had the regression analysis done, obtained the better line of adjust of the variables.

Assuntos

RESUMO

AIMS: This study was performed to determine the proportion of the parenchyma and sinus structures of pig kidneys and the distance between the collecting system and the kidney surface. METHODS: Forty-one pig kidneys were analyzed. Cavalieri's principle was used to obtain the volume of the cortex, medulla and sinus, as well the proportions of the arteries, veins and collecting system in the sinus. RESULTS: The volume of the renal parenchyma varied from 129 to 488.4 cm(3). The renal cortex was 83.79% and the medulla 16.21%. The collecting system occupied the greatest part of the sinus, ranging from 34.78 to 71.91% of the renal sinus. The collecting system was closer to the dorsal than to the ventral surface in the cranial pole (p < 0.001) and the hilar zone (p < 0.01). The distance from the collecting system to the medial border was shorter than that to the lateral border in the caudal pole (p < 0.001). CONCLUSION: With this new information about the variation in thickness of the pig renal parenchyma, continued studies using the pig model are needed to support the use of radiofrequency ablation and cryoablation in deep and large renal tumors with a component in the renal sinus.

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We tested the hypotheses that relative medullary thickness (RMT) and kidney mass are positively related to habitat aridity in rodents, after controlling for correlations with body mass. Body mass, mass-corrected kidney mass, mass-corrected RMT, mass-corrected maximum urine concentration, and habitat (scored on a semiquantitative scale of 1-4 to indicate increasing aridity) all showed statistically significant phylogenetic signal. Body mass varied significantly among habitats, with the main difference being that aquatic species are larger than those from other habitats. Mass-corrected RMT and urine concentration showed a significant positive correlation (N=38; conventional r=0.649, phylogenetically independent contrasts [IC] r=0.685), thus validating RMT as a comparative index of urine concentrating ability. RMT scaled with body mass to an exponent significantly less than 0 (N=141 species; conventional allometric slope=-0.145 [95% confidence interval (CI)=-0.172, -0.117], IC allometric slope=-0.132 [95% CI=-0.180, -0.083]). Kidney mass scaled to an exponent significantly less than unity (N=104 species; conventional slope=0.809 [95% CI=0.751, 0.868], IC slope=0.773 [95% CI=0.676, 0.871]). Both conventional and phylogenetic analysis indicated that RMT varied among habitats, with rodents from arid areas having the largest values of RMT. A phylogenetic analysis indicated that mass-corrected kidney mass was positively related to habitat aridity.

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