Extracellular Matrix Protein Signatures of the Outer and Inner Zones of the Rat Adrenal Cortex.

This study analyzes the extracellular matrix (ECM) signatures of the outer (OF = capsule + subcapsular + zona glomerulosa cells) and inner fractions (IF = zona fasciculata cells) of the rat adrenal cortex, which comprise two distinct microenvironment niches. Proteomic profiles of decellularized OF and IF samples, male and female rats, identified 252 proteins, with 32 classified as ECM-component and ECM-related. Among these, 25 proteins were differentially regulated: 17 more abundant in OF, including Col1a1, Col1a2, Col6a1, Col6a2, Col6a3, Col12a1, Col14a1, Lama5, Lamb2, Lamc1, Eln, Emilin, Fbln5, Fbn1, Fbn2, Nid1, and Ltbp4, and eight more abundant in IF, including Col4a1, Col4a2, Lama2, Lama4, Lamb1, Fn1, Hspg2, and Ecm1. Eln, Tnc, and Nid2 were abundant in the female OF, while Lama2, Lama5, Lamb2, and Lamc1 were more abundant in the male IF. The complex protein signature of the OF suggests areas of tissue stress, stiffness, and regulatory proteins for growth factor signaling. The higher concentrations of Col4a1 and Col4a2 and their role in steroidogenesis should be further investigated in IF. These findings could significantly enhance our understanding of adrenal cortex functionality and its implications for human health and disease. Key findings were validated, and data are available in ProteomeXchange (PXD046828).

Evaluación de la función renal para la detección y seguimiento de la enfermedad renal crónica. Documento multidisciplinario de consenso 2021. Especial atención sobre situaciones clínicas específicas / Evaluation of renal function for the detection and follow-up of chronic kidney disease. Multidisciplinaryconsensus document 2021. Special attention to specific clinical situations

Resumen El filtrado glomerular (FG) se considera el mejor índice para evaluar la función renal en la práctica clínica. Recientemente, ha ganado popularidad la utilización de ecuaciones que estiman el FG, en distintas poblaciones, a partir de los niveles séricos de algunos biomarcadores. Sin embargo, no todas las fórmulas han sido validadas en los diversos escenarios clínicos probables. Las sociedades participantes: Sociedad Argentina de Nefrología, Asociación Bioquímica Argentina, Fundación Bioquímica Argentina y Confederación Unificada Bioquímica de la República Argentina, integradas por nefrólogos y bioquímicos, realizaron un consenso actualizado sobre la utilización del FG como herramienta de detección de la enfermedad renal crónica (ERC) en la Argentina. Se analizó la bibliografía existente y, teniendo en cuenta aspectos de nuestra realidad sanitaria, se establecieron sugerencias para su utilización. Se actualizaron las indicaciones del uso del FG medido. En sucesivos capítulos se puso foco en distintos estados del FG en diversas poblaciones y situaciones. En los estados de reducción del FG, se mencionaron tanto los fisiológicos propios del envejecimiento, como los determinados por situaciones patológicas, por ejemplo, el observado en la ERC avanzada o el determinado en aquellos pacientes que recibieron un trasplante renal. Se revisaron, por otro lado, las situaciones de incremento del FG, como las observadas en el embarazo o en la obesidad. Se refirieron, asimismo, las limitaciones de la estimación del FG, se reconoció su valor en situaciones de la práctica clínica habitual, o en contextos epidemiológicos definidos y se sugirieron las ecuaciones más adecuadas para su utilización en cada caso.

Abstract The glomerular filtration rate (GFR) is considered the best index to assess the renal function in clinical practice. Recently, the use of equations to estimate GFR in different populations, based on the serum levels of some biomarkers, has gained popularity. However, not all the equations have been validated in the various likely clinical scenarios. Thus, the participating societies, i.e. the Argentine Society of Nephrology, the Argentine Association of Biochemistry, the Argentine Foundation of Biochemistry, and the Unified Confederation of Biochemistry of Argentina, composed of nephrologists and biochemists, have established an updated consensus on the use of the GFR as a tool for the detection of chronic kidney disease (CKD) in Argentina. The consensus was established on the basis of the analysis of the existing literature and taking into account aspects of the health situation in Argentina. Suggestions for the use of the GFR were made, and the indications for its use were updated. The successive chapters of the consensus consider different values of the GFR in different populations and situations. The different situations considered and reviewed include cases of a decrease in the GFR, such as the physiological one related to aging and that related to pathological situations, as observed in advanced CKD or in patients who have received a kidney transplant, as well as cases of an increase in the GRF, such as that observed in pregnancy or obesity. The consensus also mentions the advantages and limitations of the estimation of the GFR in situations of usual clinical practice or in specific epidemiological contexts, and the most appropriate equations for its use in each case is suggested.

Resumo A filtração glomerular (FG) é considerada o melhor índice para avaliar a função renal na prática clínica. Recentemente, a utilização de equações que calculam a FG, em diferentes populações, ganhou popularidade a partir dos níveis séricos de alguns biomarcadores. Entretanto, nem todas as fórmulas têm sido validadas nos diversos cenários clínicos prováveis. As sociedades participantes: Sociedade Argentina de Nefrologia, Associação Bioquímica Argentina, Fundação Bioquímica Argentina e Confederação Unificada Bioquímica da República Argentina, integradas por nefrologistas e bioquímicos, realizaram um consenso atualizado sobre a utilização da FG, como ferramenta de detecção da doença renal crônica (DRC) na Argentina. Foi analisada a bibliografia existente e, considerando aspectos da nossa realidade sanitária, foram estabelecidas sugestões para sua utilização. Foram atualizadas as indicações do uso da FG medida. Em sucessivos capítulos se colocou o foco em diferentes estados da FG em populações e situações diversas. Nos estados de redução da FG, foram mencionados tanto os fisiológicos próprios do envelhecimento, quanto os determinados por situações patológicas, por exemplo, aquele observado na DRC avançada ou o determinado naqueles pacientes que receberam um transplante renal. Por outra parte, foram revistas as situações de aumento da FG como as observadas na gravidez ou na obesidade. Foram referidas, também, as limitações da estimativa da FG, foi reconhecido o seu valor em situações da prática clínica habitual, ou em contextos epidemiológicos definidos e se sugeriram equações mais adequadas para sua utilização em cada caso.

Biometry of adrenal glands of mixed-breed dogs

Background: Differences of the size of the adrenal glands, in healthy dogs or in endocrinopathies, undermine correct diagnosis of endocrine disorders and evaluations of the adrenal cortex in relation to its size and possible correlation with endocrinopathies are rare. The aim of the present study was to perform measurements of the length, width, thickness and weight of the adrenal glands of young, adult and elderly mixed-breed dogs and correlate them with the age, sex and weight of animals. In addition, the areas occupied by the zona glomerulosa, zona fasciculata, and zona reticularis of the adrenal cortex were measured in order to establish a microscopic biometric pattern. Material, Methods & Results: The right and left adrenal glands of 12 young (six females and six males), 12 adults (six females and six males), and 12 elderly (six females and six males), all mongrels, derived from routine and necropsied in the Animal Pathology Sector of the Veterinary Hospital of the Federal University of Espírito Santo (HOVET-UFES) were weighed and the length, width, and thickness were measured. For the microscopic measurement of the adrenal cortex, 10 randomly selected samples were submitted to routine histological processing and the microscope slides were observed under a light microscope at 5× and 10× objectives, photodocumented and measurements were obtained from a random portion of the adrenal cortex and the zones composing the cortex were measured in triplicate with the aid of the computerized image analysis software. The left adrenal showed a greater average length than the right adrenal in young, adult, and elderly dogs. The size of the glands in the young and adult dogs is not influenced by the sex of the animals, but in older dogs the females had a greater mean...

POD-1/Tcf21 overexpression reduces endogenous SF-1 and StAR expression in rat adrenal cells

During gonad and adrenal development, the POD-1/capsulin/TCF21transcription factor negatively regulates SF-1/NR5A1expression, with higher SF-1 levels being associated with increased adrenal cell proliferation and tumorigenesis. In adrenocortical tumor cells, POD-1 binds to the SF-1 E-box promoter region, decreasing SF-1 expression. However, the modulation of SF-1 expression by POD-1 has not previously been described in normal adrenal cells. Here, we analyzed the basal expression of Pod-1 and Sf-1 in primary cultures of glomerulosa (G) and fasciculata/reticularis (F/R) cells isolated from male Sprague-Dawley rats, and investigated whether POD-1 overexpression modulates the expression of endogenous Sf-1 and its target genes in these cells. POD-1 overexpression, following the transfection of pCMVMycPod-1, significantly decreased the endogenous levels of Sf-1 mRNA and protein in F/R cells, but not in G cells, and also decreased the expression of the SF-1 target StAR in F/R cells. In G cells overexpressing POD-1, no modulation of the expression of SF-1 targets, StAR and CYP11B2, was observed. Our data showing that G and F/R cells respond differently to ectopic POD-1 expression emphasize the functional differences between the outer and inner zones of the adrenal cortex, and support the hypothesis that SF-1 is regulated by POD-1/Tcf21 in normal adrenocortical cells lacking the alterations in cellular physiology found in tumor cells.

POD-1/Tcf21 overexpression reduces endogenous SF-1 and StAR expression in rat adrenal cells.

During gonad and adrenal development, the POD-1/capsulin/TCF21transcription factor negatively regulates SF-1/NR5A1expression, with higher SF-1 levels being associated with increased adrenal cell proliferation and tumorigenesis. In adrenocortical tumor cells, POD-1 binds to the SF-1 E-box promoter region, decreasing SF-1 expression. However, the modulation of SF-1 expression by POD-1 has not previously been described in normal adrenal cells. Here, we analyzed the basal expression of Pod-1 and Sf-1 in primary cultures of glomerulosa (G) and fasciculata/reticularis (F/R) cells isolated from male Sprague-Dawley rats, and investigated whether POD-1 overexpression modulates the expression of endogenous Sf-1 and its target genes in these cells. POD-1 overexpression, following the transfection of pCMVMycPod-1, significantly decreased the endogenous levels of Sf-1 mRNA and protein in F/R cells, but not in G cells, and also decreased the expression of the SF-1 target StAR in F/R cells. In G cells overexpressing POD-1, no modulation of the expression of SF-1 targets, StAR and CYP11B2, was observed. Our data showing that G and F/R cells respond differently to ectopic POD-1 expression emphasize the functional differences between the outer and inner zones of the adrenal cortex, and support the hypothesis that SF-1 is regulated by POD-1/Tcf21 in normal adrenocortical cells lacking the alterations in cellular physiology found in tumor cells.

Enfoque diagnóstico de la hematuria en pediatría / Diagnostic approach to a child with hematuria

La hematuria es un hallazgo clínico observado por el paciente o un familiar cuando es macroscópica o bien incidental en un parcial de orina rutinario. La prevalencia es baja pero el enfoque diagnóstico al cual está enfrentado el clínico es amplio. La hematuria indica enfermedad, lesión o malformación del tracto urinario, por ello el médico general y el pediatra deben estar en capacidad de determinar a tiempo algunas de las causas con pronóstico grave o diagnóstico complejo que requieren la remisión al nefrólogo pediatra. Se hace énfasis en diferenciar si es o no de origen glomerular, adoptando un algoritmo de enfoque diagnóstico que orienta al clínico. Se realizó una búsqueda limitada de 2001-2014 en las principales bases de datos en inglés y español encontrando revisiones de la literatura, consensos de expertos y guías de práctica clínica basadas en la opinión de pediatras, nefrólogos y urólogos pediatras, así como de radiólogos que ofrecen una aproximación real a la imagenología. Está dirigida a personal de la salud, médicos generales y pediatras quienes enfrentan a diario esta condición clínica.

Hematuria is a clinical finding observed by the patient or a relative if it is macroscopic, or is an incidental finding in a routine urinalysis. Prevalence rate is low but the range of differential diagnoses faced by the physician is broad. Hematuria indicates disease, lesion or malformation of the urinary tract, thus the general practitioner and the pediatrician must be capable to determine the etiologies that have a poor prognosis or are difficult to diagnose which require prompt referral to a pediatric nephrologist. We emphasize on the development of a diagnostic algorithm to help the physician distinguish glomerular from non-glomerular hematuria. A limited search from 2001-2014 was conducted in the major data bases in English and Spanish finding literature reviews, expert consensus and clinical practice guidelines based on the opinion of pediatricians, and pediatric nephrologists and urologists, as well as radiologists who offer a real approach to imaging. It is oriented toward health care providers, general practitioners and pediatricians who face this clinical condition in their daily practice...

Aldosterone secretion in patients with septic shock: a prospective study.

OBJECTIVE: To assess serum levels of the main factors that regulate the activation of the zona glomerulosa and aldosterone production in patients with septic shock, as well as their response to a high-dose (250 µg) adrenocorticotropic hormone (ACTH) stimulation test. SUBJECTS AND METHODS: In 27 patients with septic shock, baseline levels of aldosterone, cortisol, ACTH, renin, sodium, potassium, and lactate were measured, followed by a cortrosyn test. RESULTS: Renin correlated with baseline aldosterone and its variation after cortrosyn stimulation. Baseline cortisol and its variation did not correlate with ACTH. Only three patients had concomitant dysfunction of aldosterone and cortisol secretion. CONCLUSIONS: Activation of the zona glomerulosa and zona fasciculata are independent. Aldosterone secretion is dependent on the integrity of the renin-angiotensin-aldosterone system, whereas cortisol secretion does not appear to depend predominantly on the hypothalamic-pituitary-adrenal axis. These results suggest that activation of the adrenal gland in critically ill patients occurs by multiple mechanisms.

Aldosterone secretion in patients with septic shock: a prospective study / Secreção de aldosterona em pacientes com choque séptico: estudo prospectivo

OBJECTIVE: To assess serum levels of the main factors that regulate the activation of the zona glomerulosa and aldosterone production in patients with septic shock, as well as their response to a high-dose (250 µg) adrenocorticotropic hormone (ACTH) stimulation test. SUBJECTS AND METHODS: In 27 patients with septic shock, baseline levels of aldosterone, cortisol, ACTH, renin, sodium, potassium, and lactate were measured, followed by a cortrosyn test. RESULTS: Renin correlated with baseline aldosterone and its variation after cortrosyn stimulation. Baseline cortisol and its variation did not correlate with ACTH. Only three patients had concomitant dysfunction of aldosterone and cortisol secretion. CONCLUSIONS: Activation of the zona glomerulosa and zona fasciculata are independent. Aldosterone secretion is dependent on the integrity of the renin-angiotensin-aldosterone system, whereas cortisol secretion does not appear to depend predominantly on the hypothalamic-pituitary-adrenal axis. These results suggest that activation of the adrenal gland in critically ill patients occurs by multiple mechanisms.

OBJETIVO: Avaliar os níveis séricos dos principais fatores que regulam a ativação da zona glomerulosa e a produção de aldosterona em pacientes com choque séptico, assim como sua resposta ao teste de cortrosina em alta dose (250 µg). SUJEITOS E MÉTODOS: Em 27 portadores de choque séptico, foram aferidos níveis basais de aldosterona, cortisol, ACTH, renina, sódio, potássio e lactato, bem como realizado teste de cortrosina. RESULTADOS: Renina se correlacionou com níveis basais de aldosterona e sua variação após teste de cortrosina. Cortisol basal e sua variação não se correlacionaram com ACTH. Apenas três pacientes apresentaram disfunção concomitante da secreção de aldosterona e cortisol. CONCLUSÕES: Ativação das zonas fasciculada e glomerulosa são independentes. Secreção de aldosterona é dependente da integridade do sistema renina-angiotensina-aldosterona, enquanto secreção de cortisol não parece predominantemente dependente do eixo hipotálamo-hipófise-adrenal. Esses resultados sugerem que a ativação da adrenal em pacientes críticos ocorre por múltiplos mecanismos.

N-POMC1-28 increases cyclin D expression and inhibits P27(kip1) in the adrenal cortex.

The Adrenocorticotropic hormone (ACTH) and Pro-opimelanocortin (POMC) 1-28N-terminal peptide (N-POMC(1-28)) have been shown to act as an adrenal mitogen in vivo. A possible role for cyclin E in the zona glomerulosa (ZG) proliferation, following ACTH and/or N-POMC(1-28) administration, has been previously demonstrated. In this study, we investigated the effect of ACTH and N-POMC(1-28) on the expression of adrenal cortex proteins related to cell cycle control such as cyclins D and P27(kip1). The administration of N-POMC upregulated cyclin D1 and D2 expression in the outer zone of the adrenal cortex; cyclin D3 expression was upregulated in the cortex inner zone even after administration of ACTH. Both ACTH and N-POMC peptides induced a decrease in the P27(kip1) expression in the ZG. These novel findings suggest that the POMC-derivate peptides, ACTH and N-POMC, promote proliferation in the adrenal cortex by upregulating the D2 and D3 cyclins and downregulating the P27(kip1) expression.

Role of intramitochondrial arachidonic acid and acyl-CoA synthetase 4 in angiotensin II-regulated aldosterone synthesis in NCI-H295R adrenocortical cell line.

Although the role of arachidonic acid (AA) in angiotensin II (ANG II)- and potassium-stimulated steroid production in zona glomerulosa cells is well documented, the mechanism responsible for AA release is not fully described. In this study we evaluated the mechanism involved in the release of intramitochondrial AA and its role in the regulation of aldosterone synthesis by ANG II in glomerulosa cells. We show that ANG II and potassium induce the expression of acyl-coenzyme A (CoA) thioesterase 2 and acyl-CoA synthetase 4, two enzymes involved in intramitochondrial AA generation/export system well characterized in other steroidogenic systems. We demonstrate that mitochondrial ATP is required for AA generation/export system, steroid production, and steroidogenic acute regulatory protein induction. We also demonstrate the role of protein tyrosine phosphatases regulating acyl-CoA synthetase 4 and steroidogenic acute regulatory protein induction, and hence ANG II-stimulated aldosterone synthesis.

Effects of intrauterine malnutrition on the renal morphology of Wistar rats: a systematic review

Introduction: Many epidemiological studies suggest that the intrauterine environment is extremely importantto the determination of the individual’s future health. Alterations in the maternal nutritional state, reflectedon the weight on birth, may program the litter for the development of diseases on the adult age. Studies withanimals exposed to intrauterine malnutrition have suggested a reduction in the number of glomeruli, as wellas arterial pressure increase. To review in the literature the alterations of the renal physiology of adult Wistarrats exposed to malnourishment during intrauterine life. Material and methods: A search was performedin the following databases: SciELO, MEDLINE, PUBMED, SCIENCE DIRECT and LILACS. The mainsearch terms were “malnutrition” and “renal function” both in Portuguese and in English. Were includedoriginal articles involving albino rats. Were excluded the review articles as well as those involving humanbeings. Results: According to Franco et al. (2009) the renal function and the number of glomeruli werereduced by the intrauterine malnutrition, predisposing the adult animals to renal diseases. For Chen and Chou(2009) the glomerular ultrastructure is not affected by maternal undernutrition, suggesting that this factordoes not contribute to the hypertension pathogenesis after maternal malnutrition. Conclusion: Intrauterinemalnourishment seems to interfere in the renal functions programming with alterations to the glomerulimorphology, but its mechanisms are yet uncertain. More randomized studies and clinical essays are suggestedin order to comprehend the factors that cause such process.

The proliferative effect of synthetic N-POMC(1-28) peptides in rat adrenal cortex: a possible role for cyclin E.

Modified synthetic N-POMC(1-28) without disulfide bridges has been shown to act as an adrenal mitogen. Cyclins and their inhibitors are the major cell cycle controls, but in the adrenal cortex the effect of ACTH and N-POMC on the expression of these proteins remains unclear. In this work, we evaluate the effect of different synthetic N-POMC peptides on the S-phase of the cell cycle. In addition, we examine the cyclin E expression in rat adrenal cortex. Rats treated with dexamethasone were injected with ACTH and/or synthetic modified N-POMC and/or synthetic N-POMC with disulfide bridges. DNA synthesis was determined by BrdU incorporation and protein expression was analyzed by immunoblotting and immunohistochemistry. The results showed that similarly to modified N-POMC without disulfide bridges, administration of synthetic N-POMC with disulfide bridges and the combination of ACTH and N-POMC promoted an increase of BrdU-positive nuclei in adrenal cortex. However, the proliferative effect of N-POMC was comparable to that of ACTH only in the zona glomerulosa. An increase in cyclin E expression was observed 6 h after N-POMC treatment in the outer fraction of the adrenal cortex, in agreement with immunohistochemical findings in the zona glomerulosa. In summary, the effect of synthetic N-POMC with disulfide bridges was similar to modified synthetic N-POMC, increasing proliferation in the adrenal cortex, confirming previous evidence that disulfide bridges are not essential to the N-POMC mitogenic effect. Moreover, cyclin E appears to be involved in the N-POMC- and ACTH-stimulated proliferation in the zona glomerulosa of the adrenal cortex.

Estereología renal en el cobayo (Cavia porcellus) / Renal stereology in the guinea pig (Cavia porcellus)

El cobayo (Cavia porcellus) es un roedor perteneciente al Orden Rodentia y a la Familia Caviidae, utilizado como animal de laboratorio y de consumo humano. Los parámetros cuantitativos del riñón entregan importante información de su morfofunción dada su labor en la homeostasis del organismo. El objetivo de este estudio fue describir el riñón de cobayo (Cavia porcellus), analizando las características estereológicas para futuros estudios experimentales. Se utilizaron 5 cobayos machos, obtenidos del Bioterio de la Universidad de La Frontera, Temuco, Chile. El riñón de cobayo pesó 3,2 g, aproximadamente. El riñón posee 140.298 glomérulos en total, Nv de 458 mm³, Vv de 7,89% y Sv de 3,58 mm²/ mm³. El volumen glomerular del riñón fue de 1,73 x 10(4)mm³ y el diámetro glomerular de 90 jm. Factores como especie, edad, peso corporal, peso y volumen renal, son importantes a considerar, ya que diferencian los resultados en investigaciones morfofuncionales.

The guinea pig, (Cavia porcellus) is a rodent pertaining to the Rodentia group and the Caviidae family, used as a laboratory animal and for human consumption. Quantitative parameters of the kidney provides important information of its morphofunction, given its labor in the organism's homeostasis. The aim or this study was to describe the kidney of the guinea pig (Cavia porcellus), analyzing the stereological characteristics for future experimental studies. Five male guinea pigs (Cavia porcellus) obtained from the Biotery of the Universidad de la Frontera, Temuco, Chile, were used. The kidney of the guinea pig weighed approximately 3.2g. The kidney has 140,298 total glomerulus, Nv of 458 mm³, Vv of 7.89% and Svof 3.58mm²/mm³. The glomerular volume of the kidney was of 1.73 x 10(4)mm³ and a glomerular diameter of 90 urn. Factors such as species, age, body weight and renal volume, are important to consider, as they differentiate the results in the morphofunctional investigations.

Distribution of cells expressing Jun and Fos proteins and synthesizing DNA in the adrenal cortex of hypophysectomized rats: regulation by ACTH and FGF2.

Protein expression of the early response genes, jun and fos, has been suggested to play an important role in the in vitro and in vivo proliferation of adrenal cells. To elucidate the immunolocalization of proliferative cells and the patterns of adrenal gland expression of members of the activating protein-1 (AP-1) family of oncogenes, we used hypophysectomized rats. The effects of adrenocorticotropic hormone (ACTH) and fibroblast growth factor 2 (FGF2) on Fos and Jun protein expression were investigated, and DNA synthesis was assessed by using bromodeoxyuridine (BrdU) incorporation. No change was detectable in the adrenal cortex at 2 days after hypophysectomy, although a reduction occurred in the number of BrdU-positive cells in the zona fasciculata. This hypophysectomy-induced early phase of adrenal cortex atrophy in the zona fasciculata was correlated with JunB protein induction, suggesting the formation of an inhibitory AP-1 complex. Accumulation of c-Jun/JunD and c-Fos/FosB, but not of JunB, in the zona fasciculata and zona reticularis implied that, after ACTH stimulation, these proteins were the principal AP-1 components in these zones. In these same zones, ACTH increased BrdU-positive cell counts, indicating that the composition of the AP-1 complex in these zones was proliferation-related. However, FGF2 induced an antagonistic modulation of the response to ACTH, by reducing the numbers of Jun-/Fos-positive cells and inhibiting DNA synthesis. Our results implicate the AP-1 family of transcription factors (in particular, the dynamics within the Jun protein family) in the regulation of cell control during ACTH-induced proliferation of the adrenal cortex.

Determinación de parámetros estereológicos en el riñón de conejo (Oryctolagus cuniculus) / Determination of the stereological parameters in the kidney of the rabbit (Oryctolagus cuniculus)

El número y volumen glomerular contiene información importante sobre la morfofunción del riñón. El objetivo de este trabajo fue determinar algunos parámetros estereológicos, compararlos con los de otros estudios y determinar patrones de normalidad, para futuros estudios experimentales. Se utilizaron 5 riñones de conejo (Oryctolagus cuniculus), obtenidos del Bioterio de la Universidad de La Frontera, Temuco, Chile. Los riñones fueron disecados y fijados en formalina tamponada al 10 por ciento, realizando una breve descripción morfológica de ellos y determinando su volumen por el método de Scherle. Las muestras fueron obtenidas por Orientator e incluidas en Paraplast®. Se utilizó un fragmento de cada riñón y de cada uno de ellos se obtuvieron 5 cortes de 5 µm, los cuales fueron teñidos con H-E y Tricrómico de Masson. El volumen promedio obtenido del riñón de conejo, fue 11,4 mm3 + - 1,146mm3. El número promedio de glomérulos en el riñón fue 195,09 + - 84,78 x 103 glomérulos; un Nv de 17,1 + - 7,43 glomérulos por mm3 y un volumen glomerular de 4,2 x 10-4 x mm3 + - 0,8 x 10-4 x mm3. El número total de glomérulos del conejo Oryctolagus cuniculus, es menor al obtenido en ovejas por Eleanor et al. (2004) de 559.000 + - 198.000 y en perros por Horster et al. (1971) de 589.000; y mayor que en ratas por Bertram et al. (1992) de 31.764 + - 3.667. El volumen glomerular fue menor que en ratas (6,6 x10-4), que en ovejas 4,39x10-4 y mayor que en perros 1,2x10-4. Estas diferencias nos incentivaron a determinar otros parámetros estereológicos que permitirán iniciar una línea de investigación experimental en este animal.

The glomerular number and volume contain important information regarding the morphofunction of the kidney.The objective of this investigation was to determine some stereological parameters, compare them to those of other investigations and determine the normalcy patterns for future experimental investigations. Five rabbit (Oryctolagus cuniculus) kidneys from the Biotery of the Universidad de La Frontera, Temuco, Chile were used.The kidneys were dissected and set in buffered formalin at 10%, doing a brief morphological description of them and determining their volume via the Scherle method. The samples were obtained by Orientator and included in the Paraplast. One fragment of each kidney was used and serialized cuts of each one of these 5 µm were obtained, which were dyed with H-E and Masson´s Trichrome. The average volume obtained from the rabbit kidney was 11.4 mm3 ± 1.146mm3. The average number of glomerules in the kidney was 195.09 ± 84.78 x 103 gomerules; a Nv of 17,1 ± 7.43 glomerules per mm3 and a glomerular volume of 4.2 x 10-4 x mm3 ±0.8 x 10-4 x mm3. The total number of rabbit Oryctolagus cuniculus glomerules, is less than that obtained in sheep by Eleanor et al.(2004) of 559.000 ± 198.000 and in dogs by Horster et al. (1971) of 589.000and higher than in rats by Bertram et al. (1992) of 31.764 ± 3.667. The glomerular volume was less than in rats (6.6 x 10-4), than in sheep 4.39x10-4 and higher than in dogs 1.2x10-4. These differences are encouraging, in order to determine other stereological parameters which would allow for the initiation of an experimental line of investigation in this animal.

Características ultraestructurales del músculo esquelético en pacientes con proteinuria glomerular / Ultrastructure of skeletal muscle in patients with glomerular proteinuria

La proteinuria produce un desbalance importante del metabolismo proteico y lipídico, que favorece la desproteinización del organismo, con grandes repercusiones sistémicas que llegan a afectar hasta el músculo esquelético. En los pacientes con falla renal, usualmente disminuye su masa muscular y se observa debilidad. Los pacientes urémicos terminales, manifiestan atrofia de las fibras musculares tipo II, además de daño miopático primario, causado probablemente por un déficit de la microcirculación. En un afán de dilucidar las posibles alteraciones ultraestructurales precoces presentes en el músculo esquelético de pacientes con glomerulopatías primarias que cursan con proteinuria, se estudiaron 4 pacientes (2 hombres y 2 mujeres) con edades entre 42 y 66 años, pertenecientes al servicio de nefrología del hospital militar ®Dr. Calos Arvelo¼ de Caracas-Venezuela. En todos ellos se realizaron mediciones de enzimas musculares (CK, LDH, AST y ALT), electromiografía de los miembros inferiores y biopsia del músculo cuadriceps femoral. En ninguno de los pacientes se observaron modificaciones en los niveles séricos de las enzimas y a excepción de uno de ellos (caso 4), los registros eletromiográficos fueron normales. A nivel ultraestructural se observó: hinchamiento de los componentes del sistema sarcotubular con presencia de tríadas prominentes, signos de atrofia muscular, núcleos hipercromáticos, glucógeno abundante y glucogenosomas. Algunos capilares intramusculares con la luz parcial o totalmente ocluida, citoplasma endotelial electrón denso, presencia de prolongaciones del citoplasma endotelial hacia la luz del capilar, vesículas pinocíticas y cavéolas. Dichos cambios nos permiten concluir el compromiso estructural del músculo esquelético en pacientes con proteinuria, el cual se hace más evidente a medida que avanza hacia la falla renal y que dicho compromiso tiene una base microvascular que condiciona cambios del metabolismo muscular.

The proteinuria produces an important unbalance of the protein and lipid metabolism that it favors thedesproteinitation of the organism, with big systemic repercussions that end up affecting the skeletal muscle. In the patients with renal failure it usually diminishes their muscular mass and weakness is observed. The terminal uremic patient, manifests atrophy of the fibers muscular type II, besides miopatic primary damage, caused probably for a deficit of the microcirculación. In a desire of elucidating the early ultraestructural alterations present in the skeletal muscle of patient with primary glomerulopaties that curse with proteinuria, four patients were studied (2 men and 2 women) with ages between 42 and 66 years, belonging to the service of nephrology of the military hospital ®Dr. Calos Arvelo¼ of Caracas-Venezuela. In all they were carried out mensurations of muscular enzymes (CK, LDH, AST and ALT), electromiografie of the inferior members and biopsy of the muscle femoral cuadriceps. In none of the patients modifications were observed in the seric levels of the enzymes and to exception of one of them (case 4); the eletromiografic registrations are normal. At ultraestructural level it was observed: swelling of the components of the system sarcotubular with presence of prominent triads, signs of muscular atrophy, hyperchromatic nuclei, abundant glucogen and glucogenosome. Some capillary ones intramuscular with the partial or completely occluded light, electron dense cytoplasm, presence of continuations of the endothelial cytoplasm toward the light of the capillary one, pinocitic vesicles and caveole. This changes allow us to conclude the structural commitment of the skeletal muscle in patient with proteinuria, which becomes more evident as it advances toward the renal failure and that said commitment has a microvascular origin that conditions changes of the muscular metabolism.

Differences between the growth regulatory pathways in primary rat adrenal cells and mouse tumor cell line.

In this study, DNA synthesis, phosphorylation of ERK1/2 and CREB proteins, as well as induction of c-Fos protein, were examined in rat adrenocortical, glomerulosa and fasciculata/reticularis cells, as well as in the Y1 cell line. We found that FGF2 was mitogenic only in glomerulosa cells and although ACTH did not activate ERK1/2, it did activate CREB protein, indicating efficient transduction of signals initiated in the ACTH receptors of rat adrenocortical cells. The FGF2 activated ERK1/2 in rat adrenal cells by a mechanism that might be modulated by upstream PKA pathway phosphorylation of MEK and despite the nonmitogenic effect of ACTH on rat adrenal cells it effectively induces c-Fos protein. The results presented herein describe distinct differences between the ACTH and FGF2 signal transduction mechanisms seen in adrenocortical cells and those observed in the Y1 cell line, indicating that, in vitro, ACTH blockage of the mitogenic effect occurs in normal adrenal cells after induction of c-Fos protein.

Reciprocal influences between the signalling pathways regulating proliferation and steroidogenesis in adrenal glomerulosa cells.

The main regulators of aldosterone secretion in adrenal gland zona glomerulosa (ZG) cells are the hormones angiotensin II (Ang II) and adrenocorticotrophin (ACTH) and small increases in the extracellular potassium (K(+)) concentration. The action of these agonists is mediated by different signalling systems - ACTH is mediated by cAMP and activation of protein kinase A while Ang II and K(+) activate two protein kinases, Ca(2+)-calmodulin-dependent protein kinase (CamK) and diacylglycerol-dependent protein kinase (PKC). Ang II, besides being one of the main agonists for the secretion of aldosterone, also stimulates proliferation of ZG cells, a process mediated by mitogen-activated protein kinases (MAPKs). Recent studies aimed at elucidating the molecular mechanisms underlying cell proliferation have shown that calcineurin is the principal regulator of MAPKs activity. The purpose of this review is to discuss experimental evidence of possible reciprocal influences between the signalling pathways regulating proliferation and steroidogenesis in ZG cells.

Inhibition of aldosterone production in rat adrenal mitochondria by 18-ethynyl-11-deoxycorticosterone: a simple model for kinetic interpretation of mechanism-based inhibitors.

A simple mathematical model for studying mechanism-based inhibitors (MBIs) is presented. The mathematical equations are deduced for an experimental protocol consisting of a first incubation of the enzyme in the presence of MBI followed by a washing protocol to eliminate free MBI. Finally enzyme activity (initial velocity) is measured with specific substrate. The representation of the final equation obtained is a straight line, and the MBI-specific association constant of velocity (k) can be calculated from its slope. The mathematical model was then challenged with the effect of 18-ethynyl-11-deoxycorticosterone (18-EtDOC) as an MBI on aldosterone biosynthesis from 11-deoxycorticosterone (DOC) in rat adrenal mitochondria. The last step of the mitochondrial biosynthesis of aldosterone consists of the conversion of DOC into corticosterone (B) or 18-hydroxy-11-deoxycorticosterone (18-OHDOC), and both steroids can then be transformed into aldosterone. The k (mM(-1) x min(-1)) values obtained for 18-EtDOC were: 451 +/- 36 for DOC to aldosterone; 177 +/- 16 for B to aldosterone; 175 +/- 15 for 18-OHDOC to aldosterone; and 2.7 +/- 0.2 for DOC to B. These results show that this MBI practically does not affect the metabolism of DOC to B in our enzyme preparation and that conversions of B and 18-OHDOC into aldosterone are catalyzed by the same enzyme.