Histology and histopathology Vol. 7, nº 2 (1992)
Ir a Estadísticas
Permanent URI for this collection
Browse
Recent Submissions
- PublicationOpen AccessEffects of omeprazole on the number of immunoreactive gastrin- and somatostatin-cells in the rat gastric mucosa(Murcia : F. Hernández, 1992) Pawlikowski, M.; Karbownik, M.; Lewinski, A.; Pisarek, Hanna; Wajs, E.; Szkudlinski, M.The effects of omeprazole - an inhibitor of gastric acid secretion - on gastrin (G)- and somatostatin (D)-cell density in the gastric antral mucosa epithelium in rats were examined, following a 5-day treatment. It was found that omeprazole increased the density of G-cells, whereas it decreased the density of D-cells. That effect was probably independent of hypergastrinaemia, since it could not be blocked by a simultaneous treatment with proglumide - a gastrin receptor blocker. It is concluded that the observed phenomenon is a direct result of a lower gastric acidity, as a consequence of omeprazole treatment.
- PublicationOpen AccessPhotoreceptor fine structure in the southern fiddler ray (Trygonorhina fasciata)(Murcia : F. Hernández, 1992) Braekevelt, Charlie R.The fine structure of the retinal lntroduction photorecéptors has been studied by light and electron microscopy in the southern fiddler ray or guitarfish (Trygonorhina fasciata). The duplex retina of this species contains only rods and single cones in a ratio of about 40:l. No multiple receptors (double cones), no repeating pattern or mosaic of photoreceptors and no retinomotor movements of these photoreceptors were noted. The rods are cylindrical cells with inner and outer segments of the same diameter. Cones are shorter, stouter cells with a conical outer segment and a wider inner segment. Rod outer segment discs display severa1 irregular incisures to give a scalloped outline to the discs while cone outer segment discs have only a single incisure. In al1 photoreceptors a non-motile cilium joins the inner and outer segments. The inner segment is the synthetic centre of photoreceptors and in this compartment is located an accumulation of mitochondria (the ellipsoid), profiles of both rough and smooth endoplasmic reticulum, prominent Golgi zones and frequent autophagic vacuoles. The nuclei of rods and cones have much the same chromatin pattern but cone nuclei are invariably located against or particularly through the externa1 limiting membrane (ELM). Numerous Landolt's clubs which are ciliated dendrites of bipolar cells as well as Müller cell processes project through the ELM, which is composed of a series of zonulae adherentes between these cells and the photoreceptors. The synaptic region of both rods (spherules) and cones (pedicles) display both invaginated (ribbon) synapses and superficial (conventional) synapses with cones showing more sites than the rods.
- PublicationOpen AccessMorphology and functional responses of isolated inner adrenocortical cells of rats infuse with interleukin-B(Murcia : F. Hernández, 1992) Rebuffat, P.; Malendowicz, L.K.; Andreis, P.G.; Meneghelli, V.; Kasprzak, A.; Nussdorfer, G.G.The effects of the prolon Ye d infusion with interleukin-1B (IL-10) (20 pM.kg- .min- ') on the function and morphology of the isolated inner cells of the rat adrenal cortex were investigated. After 3 and 5 days of IL-1B infusion, the level of circulating ACTH was below the control level, while the plasma concentration of corticosterone was strikingly elevated. After 5 days of infusion, isolated inner adrenocortical cells showed an enhanced basal and ACTH-stimulated corticosterone secretion, and showed a conspicuous hypertrophy. The acute exposure to IL-1B 10" M did not affect the secretory activity of dispersed cell from either control or IL-lB-infused rats. These findings indicate that the prolonged exposure to high levels of circulating IL-lB, like those occurring during chronic inflammatory diseases, is able to enhance the growth and steroidogenic (glucocorticoid) capacity of the rat inner adrenocortical zones. Moreover, they suggest that the mechanism underlying this adrenocorticotrophic effect of IL-1B does not involve either a stimulation of the hypophyseal ACTH release or a direct stimulatory effect of monokine on adrenocortical cells. It is suggested that IL-1B may activate an intra-adrenal paracrine regulatory mechanism.
- PublicationOpen AccessNeurotrophic factor-like effect of FPF1070 on septal cholinergic neurons after transections of fimbria-fornix in the rat brain(Murcia : F. Hernández, 1992) Akai, F.; Hiruma, S.; Sato, T.; Iwamoto, N.; Fujimoto, M.; Ioku, M.; Hashimoto, S.FPF1070 is an aqueous protein-free solution, which consists of 85% free amino acids and 15% small peptides. Our previous study showed a potent neurotrophic factor-like activity in cultured embryonic cells of dorsal root ganglia. The present study investigated whether FPF1070 regenerated the cholinergic cells in the media1 septal nucleus after axonal transections by cutting the fimbria-fornix. Fimbrial transections reduced the number of septal cholinergic cells by 30 + 3.6%, compared with the number on contralateral sides at 4 weeks. Intrapretioneal injections of FPF1070 caused 49.9 * 6.3% of the cholinergic neurons to survive. Furthermore, the cell sizes of the cholinergic neurons were significantly different: 16.4 + 4.2 pm, 14.3 I3. 8 pm in FPF1070 treatment and vehicle treatment, respectively. These results indicated that FPF1070 prevents the degeneration and atrophy of impaired cholinergic neurons by systemic administration.
- PublicationOpen AccessEtiology of the developing eye in myelencephalic blebs (my) mice(Murcia : F. Hernández, 1992) Center, Elizabeth M.; Polizotto, René S.The etiology of the eye defects in myelencephalic blebs (my) mutant mice has been poorly understood for almost seventy years. Embryos from 9 to 14 M days of gestation were subjected to Alcian blue 8GX staining for acidic glycosaminoglycan deposition in basement membrane structures of the developing eye in my stock and control specimens. In addition 12 day embryos were subjected to avidinbiotin- peroxidase labelling for laminin. At 9 - 9 M days of gestation more Alcian blue positive extracellular matrix was found in the region between the optic vesicle and the overlying putative lens ectoderm in the my stock embryos. By 12 days, there was an irregular and lesser amount of deposition of glycosaminoglycans in the len's capsule and in the «inner lirniting membrane~ of the presumptive neural retina; however, the deposition of laminin appeared to be greater in the inner lirniting membrane of the my eye. By 14 days, the damage to the eye in the my embryos can be quite extensive, and the deposition of glycosaminoglycans was very meager in this situation. It appears that irregular deposition of glycosaminoglycans in the extracellular matrix and possible increase in the amount of laminin in basement structures in my embryos indicate disruption of the normal histochemistry involved in the development of the eye. Altered histochemistry may in turn indicate changes in permeability between cells of the developing tissues which result in the blebbing.