Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Horm Metab Res ; 45(6): 430-5, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23322514

RESUMEN

In several rodent strains such as the New Zealand Obese (NZO) mouse, the incidence of obesity-associated diabetes mellitus is much higher in males than in females. In the present study, we investigated the effects of ovariectomy on glucose homeostasis in female NZO mice in order to elucidate the mechanism of their diabetes resistance. NZO females were ovariectomized at the age of 4 weeks, received a high-fat diet and body weight, body fat, glucose and insulin tolerance were investigated in comparison to sham-operated mice. In a second experiment, operated mice were fed a carbohydrate-free diet up to the age of 19 weeks before they received the high-fat diet. In comparison with a sham-operated control group, ovariectomized female NZO mice exhibited similar body weights, a reduced glucose tolerance, developed significantly higher blood glucose levels, lost insulin producing ß-cells, which finally resulted in a diabetes prevalence of 73% at the age of 16 weeks vs. 25% in controls. Similar to male NZO mice, ovariectomized females presented a more severe insulin resistance in the insulin tolerance test than sham-operated controls. Furthermore, the more severe insulin resistance in ovariectomized mice preceded the development of diabetes and pancreatic insulin depletion that was caused by a dietary regimen of carbohydrate restriction and subsequent re-exposure. In summary our data demonstrate that estrogen protects NZO females from ß-cell loss and obesity-associated diabetes mellitus. This effect is due to a reduced insulin resistance and possibly also to a reduced sensitivity of ß-cells to glucolipotoxic conditions.


Asunto(s)
Diabetes Mellitus/metabolismo , Estrógenos/deficiencia , Resistencia a la Insulina , Células Secretoras de Insulina/citología , Animales , Peso Corporal , Muerte Celular , Diabetes Mellitus/etiología , Diabetes Mellitus/fisiopatología , Femenino , Glucosa/metabolismo , Humanos , Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Ratones , Ratones Obesos , Obesidad/etiología , Obesidad/metabolismo , Obesidad/fisiopatología , Ovariectomía/efectos adversos
2.
J Comp Pathol ; 125(2-3): 122-9, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11578127

RESUMEN

Feline hypertrophic cardiomyopathy (HCM) is a disease of the ventricular myocardium, which may cause sudden death in cats, but neither the aetiology nor the effect on the circulation are well understood. Fourteen cats of either sex with naturally occurring HCM were studied post mortem. Their ages ranged from 9 months to 10 years with an average age of 4.9 years. Heart weights and heart weight expressed as a percentage of body weight were elevated (27.9 g and 0.65%, respectively) as compared with normal values obtained in previous studies. Myocardial disarray was evident in nine of the 14 cats and moderate to severe fibrosis was present in six animals. To evaluate the renal renin-angiotensin system, semiquantitative morphometric data were obtained by means of renin immunohistochemistry and compared with results from an earlier study of 10 healthy cats by the author. The juxtaglomerular index was 36.8% in the cats with HCM as compared with 30.6% in healthy cats. The renin-positive portion of the afferent arteriole was increased in cats affected by HCM to 86.0 microm as compared with 49.9 microm in normal cats. The increase in kidney renin values in cats with HCM may have been due to decreased blood pressure and reduced renal perfusion resulting from impaired cardiac output.


Asunto(s)
Cardiomiopatía Hipertrófica/veterinaria , Enfermedades de los Gatos/metabolismo , Sistema Renina-Angiotensina/fisiología , Animales , Arterias/metabolismo , Arterias/patología , Cardiomiopatía Hipertrófica/metabolismo , Cardiomiopatía Hipertrófica/patología , Enfermedades de los Gatos/patología , Gatos , Femenino , Ventrículos Cardíacos/patología , Inmunohistoquímica/veterinaria , Aparato Yuxtaglomerular/metabolismo , Riñón/irrigación sanguínea , Riñón/patología , Masculino , Atrofia Muscular/patología , Atrofia Muscular/veterinaria , Miocardio/metabolismo , Miocardio/patología , Tamaño de los Órganos , Renina/metabolismo
3.
Anat Histol Embryol ; 28(1): 45-8, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10208035

RESUMEN

The intrarenal distribution of renin in the cat kidney was evaluated in a semi-quantitative immunocytochemical study using a cross-reacting antiserum directed against purified renin. In addition, the morphology of the juxtaglomerular apparatus was studied electron-microscopically. The majority of renin in the cat kidney was located in the distal portion of the afferent arteriole. The values for the juxtaglomerular index and the renin-positive portion of the afferent arteriole were 30.6 +/- 3.2% and 49.9 +/- 8.3 microns, respectively. In addition, scattered renin-positive cells were found far from the vascular pole and even in the interlobular artery. Also, some vasa efferentia contained renin-positive cells. In 70% of the cats studied, renin-positive cells were located in the glomerular mesangium. The majority of the renin-positive mesangial cells were located in the vicinity of the glomerular stalk, but in some cases the centrilobular mesangium also contained renin-positive cells.


Asunto(s)
Arteriolas/enzimología , Aparato Yuxtaglomerular/enzimología , Aparato Yuxtaglomerular/ultraestructura , Circulación Renal , Renina/análisis , Animales , Arteriolas/citología , Gatos , Femenino , Mesangio Glomerular/irrigación sanguínea , Masculino
4.
J Comp Pathol ; 115(3): 239-52, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8923235

RESUMEN

The kidneys of eight male and two female cats with subacute (clinical illness 1-3 months) to chronic (clinical illness > 3 months) renal failure were examined histopathologically, electron microscopically and immunohistochemically. Semiquantitative morphometric data, obtained by measurement of the reninpositive portion of the afferent arteriole (RPP) and evaluation of the juxtaglomerular index (JGI), were compared with data from three healthy control cats. On the basis of the morphometric data, the animals with renal failure could be classified in three groups showing either a stimulated (group A), an unaltered (group B) or an inhibited (group C) renin-angiotensin system. In the three group A cats the JGI and RPP were increased (45.5 +/- 3.5%; 130 microns); in the four group B cats these values were comparable with those of the controls; in the three group C animals the JGI was decreased but the RPP was unaltered (11.7% +/- 3.2%; 56 microns). The increase in kidney renin in animals affected by chronic renal failure (CRF) may have been due to a volume depletion. Prolonged CRF seemed to result in increasing hypertrophy of renal blood vessels, leading to renal hypoxia and increasing preglomerular resistance. Reduced kidney renin status may have been caused by inhibition of renin synthesis in prolonged CRF as a result of renal ischaemia.


Asunto(s)
Enfermedades de los Gatos/fisiopatología , Fallo Renal Crónico/veterinaria , Riñón/química , Riñón/citología , Sistema Renina-Angiotensina/fisiología , Renina/análisis , Animales , Gatos , Femenino , Inmunohistoquímica , Aparato Yuxtaglomerular/química , Aparato Yuxtaglomerular/citología , Aparato Yuxtaglomerular/fisiopatología , Riñón/fisiopatología , Fallo Renal Crónico/fisiopatología , Masculino , Microscopía Electrónica
5.
Cell Tissue Res ; 252(3): 687-90, 1988 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3293796

RESUMEN

Most renin-positive cells of the preglomerular arteriole are intermediate in morphological appearence between smooth muscle cells and epithelioid cells. Intermediate cells contain, in addition to secretory granules, contractile proteins arranged as a sublemmal network. The paradoxical (inhibitory) role of calcium in renin secretion is explained, on the basis of these findings, by an increased tone of the sublemmal network; this might impair the preexocytotic access of renin granules to the cell membrane.


Asunto(s)
Calcio/fisiología , Riñón/enzimología , Modelos Biológicos , Renina/metabolismo , Animales , Riñón/irrigación sanguínea , Riñón/ultraestructura , Microscopía Electrónica , Ratas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA