Adverse association between obesity and menopause in mice treated with bezafibrate, a pan peroxisome proliferator-activated receptor agonist.

OBJECTIVE: The goal of this study was to investigate the combined effects of ovariectomy (OVX) and high-fat diet (HF) on insulin sensitivity and pancreatic remodeling in C57BL/6 mice treated with bezafibrate. METHODS: Female C57BL/6 mice were subjected to OVX or surgical procedure without removal of the ovary (SHAM). Animals received standard chow (SC; 10% lipids) or HF (60% lipids). After 13 weeks on the diets, the animals were subdivided into six groups based on diet, bezafibrate treatment, or both: SHAM-SC, SHAM-HF, SHAM-HFBz, OVX-SC, OVX-HF, and OVX-HFBz. After treatment for 5 weeks, the pancreas was removed and analyzed using morphometry, stereological tools, immunostaining, and multiplex assay kits. RESULTS: SHAM-HF and OVX-HF mice showed increased fasting glucose levels, plasma insulin levels, homeostasis model of assessment for insulin resistance index, body mass, islet hypertrophy, ß-cell mass, and insulin immunostaining, but decreased GLUT2 immunostaining. Bezafibrate treatment prevented islet hypertrophy and reduced body mass, plasma insulin levels, and homeostasis model of assessment for insulin resistance index. CONCLUSIONS: OVX combined with HF accentuates the effects of menopause, leading to the development of insulin resistance. Bezafibrate treatment reduces body mass, plasma insulin levels, and pancreatic islet hypertrophy in mice fed HF.

Quantitative morphology update: image analysis / Actualización de morfología cuantitativa: análisis de imagen

Quantitative morphology is a reliable tool in developmental, clinical and aging biology. Quantitative data of histological improvement and/or impairment due to dietary manipulations or pharmacological interventions draws the attention of countless researchers worldwide. Morphometry allows a wide range of two-dimension analysis to be performed, whereas image segmentation allows the measurement of a single structure or the determination of the intensity of its color after adequate immunostaining or even the area occupied by a specific sort of cell. When it comes to unbiased analysis, consideration should be given to suitable tissue perfusion, fixation and embedding, avoiding artifacts. Furthermore, tissue shrinkage should be taken into account. In order to ensure reproducibility, one of the most important principles in scientific research, and to allow different groups to be compared, image acquisition and image segmentation emerge as crucial steps and should be standardized. This paper aims to approach some important care for appropriate tissue processing and evaluation, and shows some practical examples of how morphometry and image segmentation can be applied to your experiment.

La morfología cuantitativa es una herramienta confiable en la biología del desarrollo, clínica y en el envejecimiento. Los innumerables datos cuantitativos de mejoras histológica y / o deterioro debido a las manipulaciones dietéticas o intervenciones farmacológicas atraen la atención de los investigadores en todo el mundo. La morfometría permite realizar una amplia gama de análisis en dos dimensiones, mientras que la segmentación de imágenes permite la medición de una única estructura o la determinación de la intensidad de su color después de una adecuada inmunotinción o incluso el área ocupada por un tipo específico de célula. Cuando se trata de un análisis imparcial, debe considerarse la posibilidad de la perfusión tisular adecuada, fijación e inclusión, evitando artefactos. Además, se debe considerar la contracción del tejido. Con el fin de asegurar la reproducibilidad, uno de los principios más importantes en la investigación científica, y para permitir que diferentes grupos se comparen, la adquisición y segmentación de la imagen aparecen como pasos cruciales y deben ser estandarizados. En este trabajo se abordan algunos cuidados importantes para el procesamiento de tejidos y evaluación apropiadas, y se muestran algunos ejemplos prácticos de cómo la segmentación morfométrica y la imagen se pueden aplicar a su experimento.

Diets rich in saturated fat and/or salt differentially modulate atrial natriuretic peptide and renin expression in C57BL/6 mice.

PURPOSE: To study the effects of a diet rich in salt and/or saturated fat on atrial natriuretic peptide (ANP)-granules, hypertension, renin expression, and cardiac structure in C57Bl/6 mice. METHODS: Young adult male mice were separated into four groups (n = 12) and fed one of the following for 9 weeks: standard chow/normal salt (SC-NS), high-fat chow/normal salt (HF-NS), standard chow/high salt (SC-HS) and high-fat chow/high salt (HF-HS). Alterations in the serum ANP, ultrastructural analysis of cardiomyocytes that produce ANP, structural analysis of the left ventricle, blood pressure, renin expression, glomerular filtration rate (GFR), feed efficiency, and lipid and glucose parameters were examined. RESULTS: The HF-NS diet showed a small increase in ANP production and left ventricular hypertrophy, increased food efficiency, and abnormal lipid and glucose parameters. The SC-HS diet showed a large increase in ANP granules in myocytes and corresponding elevation in ANP serum levels, left ventricular hypertrophy, hypertension, decrease in renin levels, and increase in GFR. The combination of the two diets (HF-HS) had an additive effect. CONCLUSION: The incorporation of a high-fat high-salt diet induced ultrastructural changes in cardiomyocytes, increased the production of ANP and increased its serum level, and reduced the amount of renin in the kidney.

Maternal malnutrition during lactation alters the folliculogenesis and gonadotropins and estrogen isoforms ovarian receptors in the offspring at puberty.

In this study, we aimed to evaluate whether maternal malnutrition during lactation alters the folliculogenesis and the expression of the gonadotropins and estrogen isoforms ovarian receptors in the offspring at puberty. At parturition, dams were randomly assigned to the following groups: control (C) group, with free access to a standard laboratory diet containing 23% protein and protein-energy-restricted (PER) group, with free access to an isoenergy and protein-restricted diet containing 8% protein. After weaning, the female pups had free access to standard laboratory diet. The maternal malnutrition caused a significant increase in the number of preantral (C=13.72+/-2.87; PER=26.36+/-3.03, P<0.01) and small antral follicles (C=9.32+/-1.35; PER=17.64+/-2.33, P<0.01) and decrease in the number of primordial (C=11.72+/-1.37; PER=3.92+/-0.60, P<0.01) and Graafian follicles (C=1.84+/-0.21; PER=0.96+/-0.11, P<0.01), and corpus luteum (C=2.00+/-0.28; PER=0.80+/-0.31, P<0.01). The estradiol serum concentration was significantly higher (C=67.86+/-4.39; PER=83.29+/-2.68, P<0.05) while testosterone serum concentration did not show statistical difference (C=0.09+/-0.02; PER=0.11+/-0.01, P>0.05) in the PER group. In relation to the receptors expression, maternal malnutrition led to a significant increase in the amount of Fshr (C=0.89+/-0.04; PER=1.07+/-0.03, P<0.05) and Lhcqr (C=0.87+/-0.15; PER=1.33+/-0.08, P<0.05) transcripts and a significant decrease in the amount of Ar (C=0.59+/-0.006; PER=0.13+/-0.080, P<0.05), ER alpha (Esr1) (C=3.33+/-0.71; PER=0.74+/-0.50, P<0.05), ER beta 1 (Esr2) (C=1.33+/-0.06; PER=0.49+/-0.36, P<0.05), and ER beta 2 (Esr2) (C=3.28+/-0.60; PER=0.62+/-0.34, P<0.05) transcripts. In conclusion, perinatal maternal malnutrition can directly affect folliculogenesis at puberty probably as a consequence of changes in the ovarian expression of gonadotropins, androgen and estrogens isoforms receptors. Long-term sexual alterations could be expected in this experimental model, since a reduction in the primordial follicle number is observed, which can result in a decrease in the reproductive lifetime and an earlier termination of breeding capacity.