1,721,043 research outputs found
Studio Immunoistochimico sull'innervazione peptidergica della vescica urinaria di ratto.
No full textStudia l'innervazione della vescica urinaria di ratto in microscopia ottica ed elettronica esaminando la localizzazione immunoistochimica di diversi neuropeptidi (VIP, NPY, Gal, SOM, SP), in contemporanea all'analisi dell'innervazione vescicale attraverso l'impiego della classica impregnazione argentica ed attraverso l'uso dei markers proteina S-100 e NSE per il sistema nervoso. Traccia un quadro morfologico dell'innervazione della vescica urinaria più completo ed aggiornato rispetto a quello classico basato esclusivamente sull'innervazione duale "adrenergica-colinergica" ed evidenzia inoltre per la prima volta la presenza nella vescica urinaria dei peptidi PYY e PP
Studio compararto dell'azione citotossica del cadmio sull'encefalo e sulla neuroglia di Pesci e Rettili
No full textLa dott.ssa Favorito ha osservato nell’encefalo di Danio rerio e Podarcis sicula esposti a CdCl2: accumulo di cadmio nell’encefalo; danni isto-morfolofici ed ultrastrutturali, riduzione dell’espressione delle proteine markers astrocitarie, quali GFAP e S100, e rivelazione di fenomeni apoptotici con attivazione delle caspasi-3 e frammentazione del DNA.
La dottoranda si è avvalsa per i suoi studi di tecniche di Microscopia Ottica: specifiche colorazioni istologiche, metodo Avidina-Biotina-Perossidasi (ABC) con l’impiego di anticorpi anti-GFAP, anti-S100, immuno-impressing per la rivelazione delle Caspasi-3 e TUNEL test per la rivelazione della frammentazione del DNA nelle cellule apoptotiche. Spettroscopia ad assorbimento atomico per la determinazione del contenuto di cadmio. Tecniche di microscopia elettronica per la valutazione di danni ultrastrutturali a carico del tessuto nervoso
Confronto tra i granulociti in alcuni Elasmobranchi : Galeomorfi, Squalomorfi e Batoidei.
No full textRiconoscimento dei granulociti di varie specie di elasmobranchi. I granulociti neutrofili vengono denominati eterofili per il loro contenuto eosinofilo che ne rende difficile la distinzione dalgli eosinofili. Vengono presentate tutte le osservazioni sui granulociti da sangue circolante di esemplari dell'oceano pacifico
GFAP immunoreactive structures in the hypothalamo-hypophyseal axis of the teleost Diplodus sargus.
No full textThe glial fibrillary acidic protein (GFAP) is the characteristic cytoskeletal protein of astroglia. It is a reliable molecular marker for all astroglial cells and shows also considerable stability in its antigenic characteristics across vertebrate phylogeny. The study of astroglial cells in the hypothalamo-hypophyseal axis of the teleost fishes is particularly significant because in these vertebrates there is no distinct portal system. The adenohypophysis, unlike the other vertebrates, is directly innervated by neurosecretory fibres and the pituicytes, typical astroglial cells of the neurohypophysis, may have an active role in the release of neurohormones. We report the occurrence and distribution of GFAP immunoreactive structures in the hypothalamo-hypophyseal axis of the teleost Diplodus sargus. For this study was used a polyclonal anti-cow GFAP antiserum (DAKO): deparaffined, dehydrated sections were immunostained using the ABC technique and the Immunogold technique was applied for the ultrastructural immunodetection. GFAP-immunoreactive fibres appeared particularly organized in bundles close to the ventricles and the hypophyseal stalk. These fibres were generally thin but they appeared more thick and numerous in the hypophyseal stalk where we observed as they were projected from hypothalamus towards neurohypophysis. Thin and isolated GFAP-immunoreactive fibres, corrisponding to the pituicytic processes, were found in the all neurohypophysis where was possible also to observe the pituicytic cellular bodies immunostained. This evidence was also confirmed by ultrastructural immunodetection: the gold particles appeared on the cellular body and on the long processes of the pituicytes of Dark type
Prolactin and growth hormone cells in the reptile Chalcides chalcides
No full textProlactin (PRL) and Growth hormone (GH) cells are specific pituitary cells secerning PRL and GH respectively. These two hormones are members of a family of polypeptide which evolved from a common ancestral gene. Their molecular characteristics are indeed quite similar. Little is still known about PRL and GH cells in the reptiles. In order to develop our previous studies on the pituitary gland of the viviparous reptile Chalcides chalcides, in this paper we report the ultrastructural study of PRL and GH cells in this skink. Ultrathin sections of pituitary gland of C. chalcides females during the reproductive period were used. The immunodetection was performed by using the polyclonal anti-PRL and anti-GH antisera and the immunogold technique. PRL cells, present in the rostral and in the medial pars distalis, appeared pyriform or ovoidal, small in size with a mean diameter of 8,5(±1,2)x6,2(±0,9)μm. They showed a round nucleus and a large nucleolus. PRL cells were full of 250-350nm granules, in which was evident homogeneous material with a little area of higher density. GH cells were larger then PRL cells with a mean diameter of 10(±0,95)μm and were only observed in the caudal pars distalis. Their shape was generally globular with a peripheral and large nucleus. Unlike PRL cells, GH cells showed less numerous and smaller granules of 180-220nm. The immunogold labelling was limited in the secretory granules for both cellular types. It’s possible to conclude that, in the viviparous reptile, C. chalcides, the PRL and GH hormones, although structurally related, are secreted by two cellular types with ultrastructural characteristics quite different
IMMUNOHISTOCHEMICAL STUDY OF ADENOHYPOPHYSIAL CELLS DURING EMBRYONIC DEVELOPMENT IN THE REPTILE CHALCIDES CHALCIDES (SQUAMATA, SCINCIDAE)
No full textThe immunohistochemical avidin-biotin complex method was used to study hormone-producing cells in the adenohypophysis of the skink Chalcides chalcides during embryonic development. In Chalcides, the formation of Rathke's pouch was evident between stages 28 and 30 of embryonic development. The adenohypophysial cells begin to differentiate before the morphological development of the gland was complete. At stage 29, few corticotropic cells were present only in the dorsal face of Rathke's pouch. No other immunoreactive cell type was revealed at this stage. At stage 32, the hypophysis had developed to a great extent though it was not yet elongated in a cephalic-caudal direction. At this stage, the corticotropic cells appeared more numerous and well differentiated in the rostral pars distalis and in the pars intermedia. Melanotropic, somatotropic and gonadotropic cells appeared simultaneously, with the same distributions as in the adult skink. At stage 34, the first thyrotropic cells appeared in the pars distalis but also in the pars intermedia, whereas rare prolactin cells were observed only at stage 35 in the medial pars distalis. Between stages 36 and 38, the gland was developed in the cephalic-caudal direction and all the cell types were completely differentiated with an evident increase in the number of prolactin cells. In embryos close to birth (stages 39-40), the hypophysis and the adenohypophysial cells were already similar to those of the adult animal
Ultrastructural study of the pituicytes in the pituitary gland of the teleost Diplodus sargus
No full textAn electron microscopic study was performed on the pituitary gland of the Mediterranean teleost fish Diplodus sargus to analyse the morphological characteristics of the pituicytes. In this class of vertebrates, the pituicytes have, like other astroglial cells, a trophic and support function, but they may also play an active role in the release of neurohormones. Most of the pituicytes were of the Dark type. Their shape appeared irregular with long, thin processes protruding from the cellular body. The pituicytes protruded from the neurohypophysis as far as the adenohypophysis. Their cellular bodies were mainly located in the posterior neurohypophysis. In the adenohypophysis, pituicytic processes were intermingled with cells of the pars intermedia and pars distalis, though being more numerous in the former. These processes sometimes surrounded the whole adenohypophyseal cell. This provides further evidence for the possible role of the pituicytes in controlling the release of the pituitary hormones given that, in teleost fishes, there is no distinct portal system or true median eminence
Action of leptin on GTH cells in Podarcis sicula pituitary gland
No full textLeptin, the protein product of the ob gene, is a hormone synthesized by adipocytes that signals available energy reserves to the brain. It has an important role in the regulation of appetite and metabolism but this hormone has also pleiotropic actions in development and physiology. Some of the major actions of leptin uncovered in recent years include the promotion of linear growth through its influence on energy balance and the stimulation of secretion of pituitary growth hormone. Leptin seems to be a phylogenetically preserved protein and in non mammalian vertebrates it has been found in all major taxa (Paolucci M., 2010). In the present work we have analysed the action of leptin on the GTH cells of the lizard Podarcis sicula. The study was performed on five groups of female lizards by the intraperitoneal injection of recombinant human leptin for three consecutive days at four different concentrations. As control, one group of lizards were treated with an injection of physiological solution. Sections of 5um of the pituitary glands enclosed in paraffin were processed by histological and immunohistochemical stains. GTH cells were revealed by ABC technique using the antisera anti-human LH and anti-human FSH at working dilution of 1:100. At low doses of leptin, GTH cells showed a decrease in immunoreactivity. This evidence shows an activating action of leptin on the secretory activity of these cells. At high doses instead GTH cells appeared markedly immunoreactive and numerous. The action of the leptin on GTH cells in P. sicula appears similar to that already reported in mammals
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