Histology and histopathology Vol. 2, nº 2 (1987)

Ir a Estadísticas

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http://hdl.handle.net/10201/177470

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Immunocytochemical studies on prolactin cells in the adenohypophysis of the golden hamster
(Murcia : F. Hernández, 1987) Seu-Mei Wang; Chia-Man Lue; Huai-San Lin
Mammotrophs or prolactin (PRL) cells were identifed in the adenohypophysis of adult golden hamsters by immunocytochemical techniques with a polyclonal anti-PRL, that was proved to be specific to PRL by the dot immunoblotting test. Postembedding immunostaining was performed on Araldite thin sections by immunoperoxidase and immunogold methods. PRL cells were classified into three types according to the different size of the secretory granules. The Type A cells were usually small and angular or oval in shape, and had secretory granules ranging in diameter from 100-230 nm, and showed poorly developed organelles. The Type B and C cells were larger and round or ovoid in shape, contained larger granules, 230-280 nm and 280-570 nm, respectively, and displayed well developed organelles. Immunoreactive PRL cells in the male pituitaries were far less numerous than in the nonpregnant female glands, and were mostly of the Type A and B, whereas in the female the Type C and B cells predominated. In pregnant females, Type C cells became activated and increased in number, while the other two types decreased in proportion. In lactating females, Type A and B cells significantly increased in number at the expense of the Type C cells; meanwhile, the exocytosis of secretory granules was frequently found in all types of PRL cells. The present findings suggest that Type C and B PRL cells, especially the former, are potent in producing and releasing PRL and highly responsive to various physiological stimuli, while Type A cells are probably relatively inert in synthetic activity.
Open Access
The protective effects of a prostaglandin without antisecretory properties aginst ethanol-induced injury in the rat stomach, a histologic study
(Murcia : F. Hernández, 1987) Schmidt, Carmen L.; Henagan, Julia M.; Mitchell, Philip A.; Smith, Gregory S.; Miller, Thomas A.
This study examined the effect of 2-acetyl-2- decarboxy-15(S)-15 methyl PGF,, (PGF,,) on ethanol (EtOH) induced injury in the rat stomach to determine if a PG analogue devoid of antisecretory properties could confer full or partial gastric mucosal protection. Rats were orally administered saline or PGF,, in a dose of 0.5 or 5.0 mg1Kg. Thirty minutes later animals received varying concentrations (i.e. 25%, 50%, and 100%) of EtOH orally. Five minutes following EtOH exposure, they were killed and samples taken from identical regions of the glandular mucosa for microscopic evaluation. All concentrations of EtOH tested damaged the gastric epithelium. The injury induced by 25% EtOH was almost exclusively confined to the surface epithelium and was not altered by either dose of PGF,,, pretreatment. In contrast, both 50% and 1(10% EtOH elicited comparable damage to the gastric mucosa involving both the deep and superficial mucosa of virtually the entire epithelium. The deep injury induced by these two EtOH concentrations was prevented by both the low and high dose of PGF,,. Of particular importance the 5.0 mg dose of PGF, provided complete protection (i.e. both superficial and deep) to as much as 50% of the mucosa exposed to 50% or 100% ethanol. These findings indicate that PGF?, possesses ~~cytoprotectivep*r operties involving both the superficial and deep epithelium that are dose related.
Open Access
Anti-platelet agents reduce morphological changes of chronic hypoxic pulmonary hypertension
(Murcia : F. Hernández, 1987) Keith, lngegerd; Will, James A.; Huxtable, Ryan J.; Weir, Kenneth
The pathophysiologic mechanism by which chronic hypoxia causes pulmonary hypertension is unknown. If anti-platelet agents, or other pharmacologic interventions, altered the pulmonary vascular changes induced by hypoxia, information concerning the pathogenesis of the pulmonary hypertension or the potential therapeutic usefulness of the drugs might be obtained. In Study 1, rats exposed to chronic hypobaric hypoxia (P, = 520 mmHg) had a pulmonary arterial medial thickness of 6.7 * 0.6 p compared to 4.1 + 0.2 p * for control, normoxic rats (*p<0.05). Administration of dipyridamole (2mg/kg/day), or sulfinpyrazone (1 1 mg/ kglday) in the drinking water reduced the medial thickness to 5.0 2 0.3 p* and 5.4 2 0.5 p* respectively, thus suggesting the possible involvement of platelets in the response of the media to chronic hypoxia. In Study 2, hypoxic rats treated with the calcium blocker, flunarizine, were found to have less medial hypertrophy than a control group of hypoxic rats. This observation suggests that a decrease in transmembrane calcium flux may also reduce medial hypertrophy.
Open Access
S-100 protein in human lung neuroendocrine neoplasms. Immunohistochemical study of 14 cases and review of the literature
(Murcia : F. Hernández, 1987) Barbareschi, M.; Mauri, M.F.; Muscara, M.; Lo Re, V.
A group of lung neuroendocrine (NE) neoplasms are investigated in view of the possible presence of S-100 protein immunoreactivity in their cells. The selected tumours were classified according to Gould et al. (1983a) and Mosca et al. (1985). They comprise 5 carcinoids, 3 neuroendocrine carcinomas of the well-differentiated type, or peripheral carcinoids, 5 neuroendocrine carcinomas of the intermediate cell type, or intermediate-cell, poorly differentiated carcinomas, 3 neuroendocrine carcinomas of the microcytoma type, or small cell carcinomas-SCC and a nodal metastasis of microcytoma. All but 2 tumours were immunoreactive for neuron specific enolase (NSE). Few S-100 immunoreactive cells were detected in 4 out of 5 carcinoids, in 1 out of 3 peripheral carcinoids, in 4 out of 5 poorly differentiated carcinomas and in the 3 microcytomas examined. No S-100 positive cells were found in the SCC's nodal metastasis. The S-100 immunolabelled cells can be interpreted as dendritic reticulum cells migrating through the tumours. However, in one case of typical carcinoid, abundant S-100 positive cells were detected: their stellate morphology and their intimate relation with neoplastic cells suggest that they are part of the neoplasia as a sort of satellite cell.
Open Access
Endocrine cells of the gastric mucosa of Rana temporaria L.
(Murcia : F. Hernández, 1987) Díaz de Rada, O.; Sesma, P.; Vazquez, J.J.
The endocrine cells of the gastric mucosa of Rana temporaria have been studied according to the ultrastructure, the staining properties of the granules with Masson Fontana's and Grimelius' silver methods, silver impregnation of Davenport on deplasticised semithin sections and immunocytochemical techniques. Seven different types of endocrine cells have been described. Six were regarded as belonging to known types: G, A, EC, ECL, D and P cells. One type was considered as unclassifiable.

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