Histology and histopathology Vol.17, nº 1 (2002)
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- PublicationOpen AccessChanges in the peptidergic innervation in the carotid body of rats chronically exposed to hypercapnic hypoxia: an effect of arterial CO2 tension(Murcia : F. Hernández, 2002) Kusakabe, T.; Hirakawa, H.; Matsuda, H.; Yamamoto, Y.; Nagai, T.; Kawakami, T.; Takenaka, T.; Hayashida, Y.The abundance of neuropeptide Y (NPY)-, vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)- immunoreactive nerve fibers in the carotid body was examined in chronically hypercapnic hypoxic rats (10% O2 and 6-7% CO2 for 3 months), and the distribution and abundance of these four peptidergic fibers were compared with those of previously reported hypocapnicand isocapnic hypoxic carotid bodies to evaluate the e ffect of arterial CO2 tension. The vasculature in the carotid body of chronically hypercapnic hypoxic rats was found to be enlarged in comparison with that of normoxic control rats, but the rate of vascular e n l a rgement was smaller than that in the previously reported hypocapnic- and isocapnic hypoxic carotid bodies. In the chronically hypercapnic hypoxic carotid b o d y, the density per unit area of parenchymal NPY fibers was significantly increased, and that of VIP fibers was unchanged, although the density of NPY and VIP fibers in the previously reportetd chronically hypocapnic and isocapnic hypoxic carotid bodies was opposite to that in hypercapnic hypoxia as observed in this study. The density of SP and CGRP fibers was decreased. These results along with previous reports suggest that d i fferent levels of arterial CO2 tension change the p e p t i d e rgic innervation in the carotid body during chronically hypoxic exposure, and altered peptiderg i c innervation of the chronically hypercapnic hypoxic carotid body is one feature of hypoxic adaptation.
- PublicationOpen AccessEffects of chronic administration of either ethanol or pentanol on rat duodenum morphology(Murcia : F. Hernández, 2002) Vaquera, J.; Vaquera, A.; Girbes, T.The morphology of the rat duodenum after chronic treatment with 15% (v/v) ethanol and 4% (v/v) pentanol was studied. Male Wistar rats of experimental groups were given ethanol and pentanol for 15 weeks with food and fluid freely available. Ethanol-15% and 4% pentanol-fed rats showed a significantly reduced fluid and food intake as compared with control rats. The study of the mucosa indicated that the number of chronic inflammatory infiltrating (mononuclear cells) and goblet cells was higher in the groups of the ethanol- and pentanol-fed rats than in the control group. There was an increase in the thickness of the brush border in pentanolfed rats. Intervillus adhesion was concurrently observed in the pentanol-fed rats but not in the control or ethanolfed rats. After ethanol feeding many of the villi developed blebs at the apex of the villus or laterally on its upper half. These blebs generally remained intact. In contrast, after pentanol feeding no bleb formation was appreciated. The intake of ethanol and other short chain alcohols present in alcoholic beverages leads to mainfold disturbances on the rat duodenum. These findings suggest that the chronic ingestion of pentanol seems to promote cellular changes but less important than those observed after chronic ethanol ingestion.
- PublicationOpen AccessIIThe glycoconjugate sugar residues of the sessile and motile cells in the thymus of normal and Cyclosporin-A-treated rats: lectin histochemistry(Murcia : F. Hernández, 2002) Gheri, G.; Gheri Bryk, S.; Riccardi-Arbi, R.; Sgambati, E.; Cirri Borghi, M.B.It is well known that cell surface glycoconjugates play a determinant role in cellular recognition, cell-to-cell adhesion and serve as receptor molecules. T-lymphocytes are in strict contact with the thymic epithelial cells, which control their process of maturation and proliferation. On the other hand the normal maturation of the epithelial cells is believed to be induced by T-lymphocytes. For these reasons we have studied the glycoconjugates saccharidic moieties of the sessile and motile cells in the thymus of normal male albino Wistar rats and their changes following cyclosporin-A treatment, using a battery of seven HRPlectins. Cytochemical controls were performed for specificity of lectin-sugar reaction. Some sections were pre-treated with neuraminidase prior to staining with HRP-lectins. Our results have demonstrated, in the control rats, a large amount and a variety of terminal and subterminal oligosaccharides within and/or on the epithelial thymic cells and in macrophages. After cyclosporin-A treatment, among the thymic epithelial cells, the subcapsular, paraseptal and perivascular cells showed the loss of some sugar residues, which characterized the same cells in the intact thymus. Some hypotheses are reported on the role played by the glycoconjugate sugar residues in control and cyclosporin-A treated rats.
- PublicationOpen AccessInfluence of light-dark, seasonal and lunar cycles on the nuclear size of the pinealocytes of the rat(Murcia : F. Hernández, 2002) Martínez Soriano, F.; Armañanzas, E.; Ruíz Torner, A.; Valverde-Navarro, A.A.Morphological and physiological studies suggest a possible division of the pineal parenchyma into an external or “cortical” and another central or “medullar” layer. We have studied the possible influence of the light/dark, seasonal and lunar cycles on the nuclear size of the pinealocytes of the rat in both the hypothetical “cortical” and “medullar” layers. Forty male Wistar rats were used. Experiment was carried out in two seasons, winter and spring, two lunar phases, full moon and new moon, and the two circadian phases, photophase and scotophase. The nuclear volume of the pinealocytes, calculated from the Jacobj’s formula, was the karyometric parameter used as measurement of the nuclear size. Main results showed that nuclear volume of the cortical pinealocytes was greater than that of the medullar pinealocytes only during the photophases of winter new-moon days and spring full moon days, whereas in all the remaining situations, the greater nuclear sizes were found in the pinealocytes of the medullar layer. These results support the existence of independent morphological variations of the pinealocyte in the central and peripheral zones of the pineal gland.
- PublicationOpen AccessDiabetic nephropathy: The central role of renal proximal tubular cells in tubulointerstitial injury(Murcia : F. Hernández, 2002) Phillips, A.O.; Steadman, R.Diabetic nephropathy is now the commonest cause of end stage renal disease and accounts for 30- 40% of all patients requiring renal replacement therapy. Furthermore, the incidence of diabetic nephropathy continues to increase, in part due to the improved survival of type 2 diabetic patients as the cardiovascular mortality in this group declines (Ritz and Stefanski, 1996). Clinically incipient nephropathy is first manifest by the onset of persistent microalbuminuria, after which, overt diabetic nephropathy is heralded by the appearance of persistent proteinuria. Subsequently, there is a progressive decline in glomerular filtration rate (GFR) resulting, within 5 years, in end stage renal disease in 50% of patients (Hasslacher et al., 1989). The pathology of the renal lesions are similar in type I and II diabetes ( Taft et al., 1994), although it has been suggested that there is more heterogeneity in type II diabetes (Chihara et al., 1986). Studies analysing structural-functional relationships have demonstrated that the development of proteinuria correlates with the degree of mesangial expansion (Mauer et al., 1984; White and Bilous, 2000). Although diabetic nephropathy was traditionally considered a primarily glomerular disease, it is now widely accepted that the rate of deterioration of function correlates best with the degree of renal tubulointerstitial fibrosis (Mauer et al., 1984, Bohle et al., 1991). This suggests that although in the majority of patients the primary event is a condition manifest by glomerular changes resulting in proteinuria, the long-term outcome is determined by events in the renal interstitium. Wi t h the increasing awareness of the importance of these pathological interstitial changes, interest has focused on the role of cells, such as the epithelial cells of the proximal tubule (PTC) or the interstitial myofibroblast, in the initiation of fibrosis. The aim of the present review is to analyse the available data supporting the role for the PTC in orchestrating renal interstitial fibrosis in diabetic nephropathy as a result of glucose-dependent alterations in PTC function. The potential for subsequent e ffects on PTC-fibroblast cross-talk will also be considered.