ISSN:0002-9106    

DOI:10.1002/aja.1001580402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThis study was designed to elucidate hormone storage patterns in gonadotropes with the use of ultrastructural immunocytochemistry on serial ultrathin sections. Sets of six serial sections were stained for beta chains of LH, FSH, or the C‐Terminal sequence of ACTH, and 430 cells cut in triple or double serial section were collected from a group of seven normal adult male rats. Approximately 50‐88% of the cells containedbothLH and FSH, and most of these were Type I cells which are distinguished by their round shape and heterogeneous populations of secretion granules. Cells containing only FSH or LH constituted, on average, 19% of the population. These were a mixed group, morphologically, and included Type II cells distinguished by their angular shape and population of secretion granules, 250 nm in average diameter. Also among the FSH cells (and a few LH cells in two of the rats) were Type III cells, which resemble the corticotrope. On average, 10% of the serially sectioned cells contained only ACTH. Our findings show the presence of subpopulations of gonadotropes containing only one of the hormones, in numbers large enough to support the hypothesis that they may be partly responsible for the nonparallel release of gonadotropins. Also, the FSH‐LH cells seemed to vary in their staining intensity for the two hormones, suggesting that the gondaotropes are a fluid, heterogeneous population of cells capable of storing both or only one of the hor

ISSN:0002-9106    

DOI:10.1002/aja.1001580403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractEpithelial rudiments of adenohypohysis were removed from chick and quail embryos between days 3 and 5 of development. Chick rudiments were grafted for 11–13 days onto the chorioallantoic membrane of decapitated chick embryo hosts. Quail rudiments were cultivated in vitro for 6 days. Both grafted and cultivated Rathke's pouches differentiated into adenohypophyseal tissue. The adenohypophyseal tissue cultured on chorio‐allantoic membrane exhibited cells reacting with the following immune sera: anti‐β‐(1–24)ACTH, anti‐α‐(17–39)‐ACTH, anti‐α‐endorphin, anti‐β‐endorphin and anti‐β‐LPH, which also gave a positive reaction when applied to adenohypophysis of corresponding age which had differentiated in situ. In situ, corticotrophs were located exclusively in the cephalic lobe of adenohypophysis. Therefore, the differentiation of corticotrophs in the whole graft, i.e., from both cephalic and caudal lobes of Rathke's pouch, showed that the cells of the caudal lobe, or at least some of them, were uncommitted when the rudiment was removed. In vitro, tissue derived from Rathke's pouch contained cells reacting with antibodies to β‐(1–24)‐ACTH, α‐(17–39)‐ACTH, and β‐LPH, as did adenohypophysis from quail embryos of corresponding age (9–10 days), differentiated in situ. The differentiation of quail Rathke's pouch in vitro corroborates that differentiation can occur without influence from hypothalamus and, moreover, shows that at least some kinds of cells can differentiate without influence exerted by any other encephalic factors, and in the absence of mesenchyme. The question arises whether fibroblastic cells derived from Rathke's pouch cells act as feeder‐cell

ISSN:0002-9106    

DOI:10.1002/aja.1001580404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractFemale Sprague‐Dawley rats were hypophysectomized and the anterior pituitary gland was immediately placed under the kidney capsule. For 1 week after surgery, groups of pituitary autograft‐bearing animals were treated with twice‐daily injections of estradiol 17β (E), progesterone (P), estradiol 17β and progesterone (EP), or luteinizing hormone‐releasing hormone (LRH). Within 2–4 hours following the last injection, the pituitary grafts were removed and placed into organ culture. They were maintained in culture with or without added LRH (10−7M) for 1 hour at 37°C. The culture media were then frozen for later radioimmunoassay of FSH and LH. The tissues were kept in culture for an additional 24 hours, at which time they were fixed and prepared for immunocytochemistry or electron microscopy.Results showed that treatment of the animals with E, EP, or LRH enhanced the release of FSH and LH into the culture media, and that the release of these hormones was increaed further by acute incubation with LRH.The ultrastructure of the gonadotrophs was well maintained by treating the animals with E or the combination of E and P or with LRH. Graft tissue from animals treated with LRH, which was incubated subsequently for 24 hours with LRH, showed the best maintenance of gonadotroph morphology. This experimental procedure should be useful for obtaining gonadotrophs for use in establishing gonadotr

ISSN:0002-9106    

DOI:10.1002/aja.1001580405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe distribution of those cells in the anterior pituitary gland of the rat which stain immunohistochemically with rabbit anti‐human calcitonin serum has been examined. Immunoreactive cells were confined primarily to the ventral surface of the gland and possessed both a distribution and morphology distinct from the corticotrophs. Staining of serial thin sections with rabbit anti‐rat TSH‐subunit serum resulted in an immunoreaction in those cells that stained for calcitonin. However, not all the thyrotrophs gave a positive immunoreaction for calcitonin. It is concluded from this study that it is inappropriate to attribute calcitonin as being part of the 31K‐dalton precursor for adrenocorticotropin, a hypothesis that was proposed earlier. In the immunohistochemical reaction with anti‐calcitonin serum, it was found that relatively high concentrations of antigen (500 μg/ml) were required in absorption experiments in order to inhibit staining. Furthermore, the staining of thyrotrophs with the anti‐calcitonin serum was inhibited after preadsorption of the primary antiserum with excess rat β‐TSH (1000 μg/ml). Because of these immunochemical characteristics, it is questionable whether the calcitonin‐like material observed in the rat pituitary gland is chemically identical to that of th

ISSN:0002-9106    

DOI:10.1002/aja.1001580406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe aim of this study was to identify the neoplastic endocrine cells which contain growth hormone (GH) and prolactin (PRL), in the MtTW15mammosomatotropic tumor, with ultrastructural immunocytochemistry. We used tumors recovered after 5 to 11 weeks of tumor development, from normal (untreated) rats and from rats treated with the progestin medroxyprogesterone acetate (MPA)—a stimulator of GH secretion in these tumors. Immunocytochemical staining was done with the peroxidase‐antiperoxidase technique on ultrathin sections of tumor that had been fixed in glutaraldehyde and postfixed in osmium tetroxide. Immunospecific staining for PRL was found over small (150 nm) secretion granules, whereas staining for GH was deposited on the larger secretion granules (250 nm). Tumors from MPA‐treated rats contained profuse numbers of neoplastic cells with large, GH‐positive granules. Immunocytochemical staining for GH and PRL was also found in crinophagic, lysosome‐like inclusions, particularly in cells that contained many secretion granules. The results support the hypothesis that GH and PRL are produced by separate neoplastic endocrine cell types in the MtTW15mammosomatotropic tumor, and demonstrate the value of ultrastructural immunocytochemical analysis for functional classification of cell types in chromophobic pituitary

ISSN:0002-9106    

DOI:10.1002/aja.1001580407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractAmong 92 surgically removed pituitary adenomas immunostained for prolactin and growth hormone, 70 showed positive staining for prolactin. The majority of these (54) was associated with hyperprolactinemia leading to amenorrhea (and often galactorrhea) in women of reproductive age. Similar tumors, asymptomatic or conducive to disturbances of sexual function, were found in six hyperprolactinemic men. Among nine acromegalics, seven had immunostained lactotrophs associated with the somatotrophic adenomas cells, but only two of these had hyperprolactinemia. In all of the remaining tumors that had at least some immunoreactive lactotrophs, mild hyperprolactinemia had been present. This indicates that immunostaining of pituitary tumors for prolactin correlated well with elevated plasma prolactin levels, except in the case of mixed somatolactotrophic adenomas. The patterns of distribution of immunoreactive prolactin in adenoma cells are illustrated. Since only some of the prolactin‐producing adenomas stained with carmoisine–a dye that has been suggested as a marker for prolactin cells–immunocytochemistry is the method of choice for the identification of prolactin‐secreting a

ISSN:0002-9106    

DOI:10.1002/aja.1001580408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThree aspects of the secretory process in male rat prolactin (PRL) cells grown in primary cultures for 7–14 days have been investigated by cytochemical methods. Thesubcellular localization of prolactinhas been studied using preembedding or postembedding immunocytochemical methods after various fixatives. With postembedding method, PRL is localized essentially in secretory granules. The maximum intensity of staining is obtained with PAF fixative. With the preembedding method, subcellular localization of the staining varies depending on the fixative. After PAF‐fixation, positive staining is observed on secretory granules, ground cytoplasm, the outer face of some RER cisternae and, in a few cells, on the innermost Golgi cisternae, as well as on masses of condensing secretory material. After Ohtsuki's hypotonic fixative followed by saponin permeabilization, PRL is visualized within the totality of RER cisternae, including the perinuclear cisternae and the peripheral saccules on the cis‐Golgi face. Secretory granules are unstained.Membrane trafficwas investigated using the Con A‐HRP indirect method as a tracer of surface saccharides. Plasma membrane, coated with Con A‐HRP at 4°C, is slowly internalized at 37°C. This involves both randomly distributed invaginations and capping. The final step of endocytosis (1–2 hours) is located in the Golgi zone, where very few smooth membranes are stained. In contrast, a conspicuous deposit is found around the dense content of secretory granules. This suggests a recycling of internalized membrane and a transfer of Con A‐HRP from the inner face of smooth cisternae to the secretory material. The internalization of Con A‐HRP‐coated membrane leads to an inhibition of PRL release starting after 30 minutes. This is accompanied by a marked increase of acid phosphatase activity, mostly around forming and mature

ISSN:0002-9106    

DOI:10.1002/aja.1001580409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe hormone‐containing cells of the pars tuberalis of the rat adenohypophysis were studied, 4–5 months after hypophysectomy, with a double bridge immunocytochemical technique and with antisera directed against the hormones of the pars distalis. Corticotropes, lactotropes, somatotropes, thyrotropes, and gonadotropes were found in the pars tuberalis of all animals. These cells are well situated to receive blood, nerve terminals, and tanycyte processes from the median eminence and, thus, to be influenced by the chemical messengers from the hypothalamus. It is concluded that the pars tuberalis has to be regarded as a potential source of adenohypophyseal hormones in an animal model traditionally considered to be free of such hormo

ISSN:0002-9106    

DOI:10.1002/aja.1001580410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractGrowth hormone‐release‐inhibiting hormone (somatostatin) has been localized in several central nervous system sites, but the contribution of somatostatin in these various loci to the control of growth hormone (GH) production is unclear. In the present study, the efficacy of castration, alone, or with subsequent gonadal steroid administration, in modulating hypophysial GH production was examined, and the response of somatostatin‐containing nerve endings in the median eminence and the organum vasculosum of the lamina terminalis (OVLT) was evaluated by means of immunocytochemistry. Orchidectomy reduced the size and number of immunoreactive GH‐cells, and testosterone administration prevented this change. Ovariectomy appeared to stimulate the somatotropes, but this effect was neither as dramatic nor as consistent as the effect of castration in the male. Administration of estradiol, however, resulted in a marked reduction in the number, size, and GH content of somatotropes in all animals examined. Somatostatin was localized in the external lamina of the median eminence and in nerve endings surrounding the core of capillaries in the OVLT. Only the median eminence responded to steroid manipulations with a visible change in the immunoreactive pool of somatostatin, with a decrease following orchidectomy, which was reversible by testosterone treatment, and an increase following ovariectomy, which was reversible by estradiol treatment. However, as in the GH responses to steroid manipulations, the somatostatin responses were more variable in females than in males.These results suggest that: (1) testosterone promotes and estradiol, at least at high doses, inhibits storage of GH in the anterior pituitary; (2) these changes in GH production may be regulated, in part, by altered somatostatin release from the median eminence into the hypophysial portal blood; and (3) somatostatin in the OVLT may not be involved in the steroid‐induced modulation of GH p

ISSN:0002-9106    

DOI:10.1002/aja.1001580411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY