Effects of bromocriptine on serum prolactin levels, pituitary weight and immunoreactive prolactin cells in estradiol-treated ovariectomized rats : an experimental model of estrogendependent hyperprolactinemia

The present study was designed to assess the effects of bromocriptine, a dopamine agonist, on pituitary wet weight, number of immunoreactive prolactin cells and serum prolactin concentrations in estradioltreated rats. Ovariectomized Wistar rats were injected subcutaneously with sunflower oil vehicle or estradiol valerate (50 or 300 μg rat-1 week-1) for 2, 4 or 10 weeks. Bromocriptine (0.2 or 0.6 mg rat-1 day-1) was injected daily during the last 5 or 12 days of estrogen treatment. Data were compared with those obtained for intact control rats. Administration of both doses of estrogen increased serum prolactin levels. No difference in the number of prolactin cells in rats treated with 50 μg estradiol valerate was observed compared to intact adult animals. In contrast, rats treated with 300 μg estradiol valerate showed a significant increase in the number of prolactin cells (P<0.05). Therefore, the increase in serum prolactin levels observed in rats treated with 50 μg estradiol valerate, in the absence of morphological changes in the pituitary cells, suggests a “functional” estrogen-induced hyperprolactinemia. Bromocriptine decreased prolactin levels in all estrogen-treated rats. The administration of this drug to rats previously treated with 300 μg estradiol valerate also resulted in a significant decrease in pituitary weight and number of prolactin cells when compared to the group treated with estradiol alone. The general antiprolactinemic and antiproliferative pituitary effects of bromocriptine treatment reported here validate the experimental model of estrogen- induced hyperprolactinemic rats

Gastrinoma : aspectos diagnósticos e terapêuticos de um caso

Os autores relatam o caso de uma paciente feminina com 46 anos, com úlceras pépticas recidivantes há dois anos. Ela foi submetida a tratamento clínico e cirúrgico sem resultados, com recidiva de úlcera de neoboca. Na segunda cirurgia, realizada no Hospital de Clínicas de Porto Alegre, constatou-se a presença de processo expansivo comprometendo o corpo do pâncreas, com imvasão da cabeca e cauda infiltrando estruturas vizinhas como o duodeno, antro gástrico e linfonodos regionais. O exame histo-patológico revelou neoplasia de células das ilhotas de Langerhans, cujo estudo imuno-histoquímico demonstrou secreção de gastrina e de enolase neuronal específica pelas células tumorais, caracterizando-o como um gastrinoma e síndrome de Zollinger-Ellison. O caso relatado mostrou níveis séricos de gastrina persistentemente normais, fato que justifica o seu relato, além da sua raridade.The authors report a case of a patient, fem, 46years old with recurrent peptic ulcers for about two years. Clinical and surgical treatment was tried, without results, so presenting recurrence of a marginal ulcer. In the second surgery, performed in the Hospital de Clínicas de Porto Alegre, we observed an expansive tumor in the body of the pancreas with head and tail invasion. Duodenum, gastric antrum and regional limphonodes were infiltrated by this tumor. Histo-pathologic examination revealed a Langerhans islet tumor. The imunehistochemical study of tumoral cells was positive to gastrinoma and Zollinger-EIIison syndrome. Different from other cases, gastrineseric levels were persistently normal, justifying then this report

Hemorragias em metastases intracranianas de melanoma: registro de dois casos

São relatados dois casos de metastases cerebrais de melanoma maligno cuja manifestação clínica foi de hemorragia cérebro-meníngea. É feita a revisão da literatura pertinente, enfatizando-se a importância da inclusão das metastases no diagnóstico diferencial das hemorragias cerebrais e da realização de biópsia da parede de hematomas intra-cerebrais espontâneos

Aversive stimulation during the stress-hyporesponsive period does not affect the number of corticotroph cells in neonatal male rats

Immunohistochemistry was used to evaluate the effects of neonatal handling and aversive stimulation during the first 10 days of life on the number of corticotrophs in the anterior lobe of the pituitary of 11-dayold male Wistar rats. Since adult rats handled during infancy respond with reduced corticosterone secretion in response to stressors and with less behavior inhibition in novel environments, we assumed that neonatal stimulation could affect pituitary morphology during this critical period of cell differentiation. Three groups of animals were studied: intact (no manipulation, N = 5), handled (N = 5) and stimulated (submitted to 3 different aversive stimuli, N = 5). The percentage of ACTH-immunoreactive cells in the anterior lobe of the pituitary (number of ACTH-stained cells divided by total number of cells) was determined by examining three slices per pituitary in which a minimum of 200 cells were counted by two independent researchers. Although animals during the neonatal period are less reactive to stresslike stimulation in terms of ACTH and corticosterone secretion, results showed that the relative number of ACTH-stained cells of neonatal handled (0.25 ± 0.01) and aversive stimulated (0.29 ± 0.03) rats was not significantly different from intact (0.30 ± 0.03) animals. Neonatal stimulation may have a differential effect on the various subpopulations of corticotroph cells in the anterior pituitary