Soy extract-dependent changes in morphofunctional parameters of the pituitary corticotropes in adult rats

Numerous studies have established a link between estrogen levels and activity of the hypothalamic pituitary adrenal (HPA) system. Considering the “weak estrogenic” effect of soy isoflavones, this study was designed to evaluate the influence of soy extract treatment on some morphofunctional parameters of rat pituitary corticotropes in vivo. Adult male orchidectomized Wistar rats received estradiol-dipropionate or soy extract in oil/ethanol solvent subcutaneously for 3 weeks. Both controls, sham-operated (So) and orchidectomized (Orx) rats, were injected with solvent, in the same regime. Changes in pituitary volume, total volume, total number and volume of individual corticotropes were evaluated stereologically, while ACTH levels were determined biochemically. In comparison with So rats, estradiol treatment provoked increases (p < 0.05) of: ACTH level (166%), pituitary weight (167%) and volume (102%), total volume (20%) and total number of corticotropes (18%). In comparison to Orx, following estradiol treatment elevation (p < 0.05) of: ACTH level (69%), pituitary weight (131%) and volume (82%), total (30%) and individual volume (29%) of corticotropes was observed. Soy extract treatment led to enhancement (p < 0.05) of: ACTH level (28%), total (25%) and individual volume (20%) of corticotropes. It can be concluded that soy extract acts in a similar way to estradiol, but the increased activity of corticotropes was weaker.     

The phytoestrogen genistein prevents trabecular bone loss and affects thyroid follicular cells in a male rat model of osteoporosis

As a major phytoestrogen of soy, genistein effectively prevents bone loss in both humans and rat models of osteoporosis. However, although the bone‐sparing effects of genistein are achieved directly through estrogen receptors, its mode of action on bone by modulation of other endocrine functions is not entirely clear. Thus, thyroid hormones and calcitonin (CT ) have an essential influence on bone metabolism. Besides its action on bones, in this study we examined the effect of genistein on the activity of two different endocrine cell populations, thyroid follicular and C‐cells. Fifteen‐month‐old Wistar rats were either bilaterally orchidectomized (Orx) or sham‐operated (SO ). Two weeks after surgery, half of the Orx rats were treated chronically with 30 mg kg^?1 b.w. genistein (Orx + G) subcutaneously (s.c.) every day for 3 weeks, while the remaining Orx rats and the SO rats were given the same volume of sterile olive oil to serve as controls. For histomorphometrical analysis of the trabecular bone microarchitecture an ImageJ public domain image processing programme was used. Thyroid sections were analysed histologically and stereologically after visualization of follicular and C‐cells by immunohistochemical staining for thyroglobulin and CT . Thyroid follicular epithelium, interstitium, colloid and CT ‐immunopositive C‐cells were examined morphometrically. Serum concentrations of osteocalcin (OC ), triiodothyronine (T₃), thyroxine (T₄) and CT were determined as well as urinary calcium (Ca²⁺) concentrations. Genistein treatment significantly increased cancellous bone area (B.Ar), trabecular thickness (TbTh) and trabecular number (TbN) (P  < 0.05), but trabecular separation (Tb.Sp) was decreased (P  < 0.05) compared with control Orx rats. In the thyroid, genistein treatment significantly elevated the relative volume density (Vv) of the follicular cells (P  < 0.05) compared with Orx, whereas Vv of the colloid was lower (P  < 0.05) than in the Orx. Evaluation of the biochemical parameters showed significant reductions in serum OC , T₃, T₄ and urinary Ca²⁺ concentrations (P  < 0.05), compared with Orx rats. These data indicate that genistein treatment improves the trabecular microarchitecture of proximal tibia, induces histomorphometrical changes in thyroid glands, and decreases circulating thyroid hormone levels in orchidectomized rat model of male osteoporosis.     

Effects of genistein on gonadotropic cells in immature female rats

The effects of genistein on pituitary gonadotropic cells of immature female rats were examined and compared to actions of the synthetic estrogen, 17α-ethynylestradiol. Immature female rats received 50 mg/kg/bw of genistein in dimethylsulfoxide (DMSO) subcutaneously (s.c.) daily for 3 days at 18, 19 and 20 days of age. A second group was injected with 1 μg/kg of 17α-ethynylestradiol in olive oil in the same schedule. The genistein control group received DMSO only, while 17α-ethynylestradiol controls were given sterile olive oil only. Changes in cell number per mm², cell volume and volume density of follicle-stimulating (FSH) and luteinizing (LH) immunolabeled cells were evaluated by morphometry and stereology. Genistein induced significant increases in the number of FSH cells (by 21%) and LH cells (by 20%) per mm² compared to corresponding controls. Volumes of FSH and LH cells were significantly increased by 19.7% and 20% and their volume densities by 20% and 20.2%, respectively. Estradiol markedly affected gonadotropes in the same manner, but to a greater extent. It can be concluded that genistein acted as an estrogenic agonist in the pituitaries of immature female rats, and as such, stimulated gonadotropic cells.     

Immunohistochemical identification of mouse adenohypophysial gonadotropes

Mouse pituitary gonadotropes were identified using immunohistochemical techniques with OsO4 single fixation. Most gonadotropes are immunostained with both LH beta and FSH antisera (FSH/LH gonadotropes), whereas a few gonadotropes are positive only for LH beta (LH gonadotropes). The former gonadotropes are large rounded or oval cells and contain two types of secretory granules: electron-dense smaller ones (about 100-200 nm in diameter) and electron-transparent larger ones (maximum diameter, about 400 nm) enclosed by a halo. The endoplasmic reticulum appears as a series of dilated sacs, and the Golgi apparatus is distinct. The mitochondria are found to have an electron-dense matrix throughout the cytoplasm, but are often concentrated in and around the region of the Golgi apparatus. These fine structural features are somewhat similar to those of the classical Barnes "FSH cell" The LH gonadotropes are polygonal cells of medium size. Small granules, as described above, are seen, but large granules are not. The Golgi apparatus is distinct, but small. The LH gonadotropes resemble neither the Barnes "LH cell" nor the Kurosumi-Oota "LH cell".     

Immunohistochemical study of adenohypophysial gonadotropes in the musk shrew, Suncus murinus L. (Insectivora)

Most gonadotropes in the pituitary of male Suncus murinus L. are immunostained with both LH beta and FSH antisera, whereas only a few gonadotropes are positive only for LH beta. The former gonadotropes consist of polygonal or polyhedral cells of medium size, and can be identified by the presence of two types of secretory granules of low density: smaller ones (about 150-250 nm in diameter) which are spherical in shape, and larger ones of irregular form with a maximum diameter of about 1,500 nm. The endoplasmic reticulum is not prominent, while the Golgi apparatus is distinct. Mitochondria are found throughout the cytoplasm but are often concentrated in and around the region of the Golgi apparatus. These fine structural features are somewhat similar to those of the classical Barnes "FSH cells" and Kurosumi-Oota "FSH cells".     

Individual and combined soy isoflavones exert differential effects on metastatic cancer progression

To investigate the effects soy isoflavones in established cancers, the role of genistein, daidzein, and combined soy isoflavones was studied on progression of subcutaneous tumors in nude mice created from green fluorescent protein (GFP) tagged-MDA-MB-435 cells. Following tumor establishment, mice were gavaged with vehicle or genistein or daidzein at 10 mg/kg body weight (BW) or a combination of genistein (10 mg/kg BW), daidzein (9 mg/kg BW), and glycitein (1 mg/kg BW) three times per week. Tumor progression was quantified by whole body fluorescence image analysis followed by microscopic image analysis of excised organs for metastases. Results show that daidzein increased while genistein decreased mammary tumor growth by 38 and 33% respectively, compared to vehicle. Daidzein increased lung and heart metastases while genistein decreased bone and liver metastases. Combined soy isoflavones did not affect primary tumor growth but increased metastasis to all organs tested, which include lung, liver, heart, kidney, and bones. Phosphoinositide-3-kinase (PI3-K) pathway real time PCR array analysis and western blotting of excised tumors demonstrate that genistein significantly downregulated 10/84 genes, including the Rho GTPases RHOA, RAC1, and CDC42 and their effector PAK1. Daidzein significantly upregulated 9/84 genes that regulate proliferation and protein synthesis including EIF4G1, eIF4E, and survivin protein levels. Combined soy treatment significantly increased gene and protein levels of EIF4E and decreased TIRAP gene expression. Differential regulation of Rho GTPases, initiation factors, and survivin may account for the disparate responses of breast cancers to genistein and daidzein diets. This study indicates that consumption of soy foods may increase metastasis.     

The pars tuberalis of the human pituitary

Summary Forty autopsy pituitaries were studied to elucidate the histology, immunocytology and ultrastructure of pars tuberalis in subjects with normal and abnormal endocrine homeostasis. Pars tuberalis consisted mainly of gonadotrophs interspersed with few corticotrophs and thyrotrophs, histologically resembling those of pars distalis. Somatotrophs and lactotrophs were not identified. There were no histologic differences attributable to age or sex. In cases of glucocorticoid excess, pars tuberalis corticotrophs showed Crooke's hyalinization. Following castration or hypophysectomy, pars tuberalis gonadotrophs exhibited more intense immunostaining for FSH¹ and LH than did normals. Ultrastructural analysis revealed gonadotrophs and corticotrophs showing no evidence of active secretion; immunoelectron microscopy demonstrated FSH, LH and ACTH in secretory granules. By light microscopy, squamous nests, often identified in pars tuberalis, were positive for immunoreactive keratin; cells at their periphery contained FSH, LH or ACTH, indicating derivation of nests by squamous metaplasia from gonadotrophs and corticotrophs. By electron microscopy, clusters of epithelial cells containing desmosomes and tonofilaments were surrounded by granulated gonadotrophs.Human pars tuberalis cells represent mainly a subpopulation of gonadotrophs possessing all organelles required for synthesis and storage of hormones but showing ultrastructural features of functional inactivity; the reasons for this inactivity and for the formation of squamous nests remain unexplained.     

Identification of immunoreactive FSH and LH cells in the cichlid fish Cichlasoma dimerus during the ontogeny and sexual differentiation

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) expressing cells were detected in pituitary, brain and ovary of the Perciform cichlid fish Cichlasoma dimerus. This detection was carried out by immunohistochemistry (IHC) and Western blot techniques using antisera of the Cyprinodontiform Fundulus heteroclitus raised against the conservative region of the teleost βFSH and the βLH subunits. The estimated molecular weights were 24 kDa for LH and 19 and 15 kDa for FSH. In the adult pituitary, both cell types were distributed along mid and ventral zones of the proximal pars distalis (PPD, mid-immunoreactive cells), and along the ventral and dorsal external border of the pars intermedia (PI, high-immunoreactive cells). Double IHC showed that FSH and LH are mainly expressed in different pituitary cells. FSH cells were detected in the pituitary around day 21 after hatching (ah) (prior to sex differentiation), while LH cells were detected by day 60 ah (during the sexual differentiation period). A correlation between gonadal sex differentiation and FSH was demonstrated in a 15 days organ culture system. FSH and LH neurons were localized in the nucleus lateralis tuberis and their fibers project through the ventral hypothalamus, preoptic area and neurohypophysis. FSH neurons differentiated on day 21 ah, while LH neurons appeared on day 15 ah. In the ovary, the immunoreactivity for both FSH and LH was restricted to the cytoplasm of previtellogenic and early vitellogenic oocytes.     

The effects of sex steroids on thyroid C cells and trabecular bone structure in the rat model of male osteoporosis

Androgen deficiency is one of the major factors leading to the development of osteoporosis in men. Since calcitonin (CT) is a potent antiresorptive agent, in the present study we investigated the effects of androgen deficiency and subsequent testosterone and estradiol treatment on CT-producing thyroid C cells, skeletal and hormonal changes in middle-aged orchidectomized (Orx) rats. Fifteen-month-old male Wistar rats were either Orx or sham-operated (SO). One group of Orx rats received 5 mg kg⁻¹ b.w. testosterone propionate (TP) subcutaneously, while another group was injected with 0.06 mg kg⁻¹ b.w. estradiol dipropionate (EDP) once a day for 3 weeks. A peroxidase–antiperoxidase method was applied for localization of CT in the C cells. The studies included ultrastructural microscopic observation of these cells. The metaphyseal region of the proximal tibia was measured histomorphometrically using an imagej public domain image processing program. TP or EDP treatment significantly increased C cell volume (Vc), volume densities (Vv) and serum CT concentration compared with the Orx animals. Administration of both TP and EDP significantly enhanced cancellous bone area (B.Ar), trabecular thickness (Tb.Th) and trabecular number (Tb.N) and reduced trabecular separation (Tb.Sp). Serum osteocalcin (OC) and urinary Ca concentrations were significantly lower after these treatments in comparison with Orx rats. These data suggest that testosterone and estradiol treatment in Orx middle-aged rats affect calcitonin-producing thyroid C cells, which may contribute to the bone protective effects of sex hormones in the rat model of male osteoporosis.     

An immunocytochemist's view of gonadotropin storage in the adult male rat: Cytochemical and morphological heterogeneity in serially sectioned gonadotropes

This 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 contained both LH 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 hormones.     

Response of trabecular bone,thyroid C and follicular cells to synthetic salmon calcitonin in middle‐aged orchidectomized male rats

In contrast to studies in women, male osteoporosis is poorly understood and strictly related to advancing age. Among the first antiresorptive substances used in the prevention and treatment of osteoporosis is calcitonin (CT), a hypocalcemic hormone that potently inhibits osteoclastic bone resorption. Natural CT is produced and secreted by thyroid C‐cells. The other endocrine population of thyroid cells produces thyroid hormones (TH), which also affect bone turnover. The aim of this study was to evaluate the influence of salmon CT on trabecular bone microarchitecture with special reference to effects on the structure and function of both CT‐ and TH‐producing thyroid cells in orchidectomized (Orx) middle‐aged rats. Twenty‐four male Wistar rats aged 15 months were randomly divided into Orx and sham‐operated (SO) groups. One group of Orx animals received (s.c.) synthetic salmon CT (Orx + CT; 100 IU kg⁻¹ b.w.) subcutaneously every second day for 6 weeks. The second Orx group and SO rats were given the same volume of vehicle alone by the same schedule. Trabecular bone histomorphometrical parameters were: cancellous bone area (B.Ar), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) were obtained with an ImageJ public‐domain image‐processing program. The peroxidase–antiperoxidase method was applied for localization of CT in C‐cells. Anti‐human CT antisera served as the primary antibodies. For immunohistochemical characterization of vascular endothelial growth factor (VEGF) in thyroid tissue, rabbit antisera against human VEGF, served as primary antibodies. CT‐immunopositive thyroid C‐cells, thyroid follicular epithelium, interstitium and colloid were evaluated morphometrically. Blood serum samples were analyzed for CT, osteocalcin (OC), and thyroxine (T₄), and calcium (Ca²⁺) concentration was determined in urine samples. Salmon CT application significantly increased B.Ar, TbTh and TbN, but markedly decreased Tb.Sp. Administration of exogenous CT significantly decreased mean volume (Vc) and relative volume density (Vv) of thyroid C‐cells in relation to both SO and Orx groups. The Vv of the colloid was higher, whereas the V_V of the follicular epithelium was lower after CT treatment compared with Orx alone. CT treatment markedly elevated serum CT, whereas serum OC, T₄ and urinary Ca²⁺ concentrations were lower than in the Orx group. These results indicate that salmon CT stimulates trabecular bone microarchitecture, strongly inhibits thyroid C‐cells and changes the structure of the thyroid gland, indicating hypoactivity.     

Analysis of histophysiologic responses of the rat hypophysis to androgen treatment

The concentrations of LH and FSH were measured in the blood and adenohypophyses of castrated male rats exposed to high levels of testosterone propionate for 1 to 18 weeks. In intact male and female rats, similarly treated for 1 to 5 weeks, blood levels could not be measured but pituitary hormone levels were. Histological study of the pituitary gonadotrophic cells of all groups revealed a striking correlation between their regression, in response to androgen treatment, and the decline in pituitary LH stores. No light-microscopic correlate of the marked, progressive increase in pituitary FSH concentration was detected. Thus, when the pituitary FSH:LH ratio had increased 90 fold, all gonadotrophs appeared inactive. Although these studies failed to reveal the specific cellular source(s) of FSH and LH, they did clarify several aspects of the dynamics of the pituitary secretory responses to orchidectomy and androgen treatment. In the light of this information, the suggestion is made that the greatest dichotomy between pituitary FSH and LH stores is not coincident with — and probably occurs later than — that between LH and FSH secretion. Such asynchrony between the various phases of the FSH and LH secretory responses to these treatments (castration and/or androgen administration), may explain several seeming discrepancies among earlier reports on this subject.     

Pregnancy and dexamethasone: effects on morphometric parameters of gonadotropic cells in rats

The effects of pregnancy and multiple dexamethasone (Dx) treatment on morphometric parameters of adenohypophyseal gonadotropic cells that produce follicle stimulating hormone (FSH) and luteinizing hormone (LH) were investigated in female Wistar rats. The rats in the experimental group received injections of 1.0, 0.5 and 0.5mg Dx/kg b.w. on days 16-18 of pregnancy, while the control group received equal volumes of saline. There was also an age-matched adult virgin control group. The experimental and control animals were sacrificed 24 and 72h after the last injection. Using the peroxidase-anti-peroxidase immunohistochemical labeling procedure, morphometric analyses showed that cell volume and volume density of FSH and LH cells on day 19 of pregnancy, as well as the number of LH cells, were significantly decreased compared to the virgin control values. On day 21 of gestation, the volume of FSH and LH cells remained smaller than in the virgin controls. Moreover, FSH and LH cell volume was significantly decreased 24h after multiple Dx treatment in comparison with the pregnant controls. Thus, during the last days of pregnancy, the morphometric parameters of gonadotropic cells decreased in comparison with the control virgin rats, but Dx treatment of pregnant rats had an inhibitory influence on FSH and LH cell size only 24h after the last dose.     

The ultrastructure of the stellate cell in the rabbit pars distalis,

Stellate cells in the rabbit pars distalis have been studied electron microscopically from birth to adulthood. During this period the stellate cells are found in abundance throughout the pars distalis and are the only consistently agranular cells observed in the pars distalis parenchyma. Identifying features of stellate cells are fine cytoplasmic filaments and farreaching cytoplasmic processes. The cytoplasmic processes ramify between adjacent parenchymal cells and are connected to other stellate cells by desmosomes. The stellate cells, linked to one another by desmosomes, thus constitute a meshwork within which the granulated parenchymal cells reside. Processes of stellate cells are also found interposed between the parenchymal basal lamina and the granulated parenchymal cells. The cytoplasmic filaments are distributed throughout the cytoplasm and extend into the fine processes. The filaments do not appear to have any particular orientation to the plasma membrane. Compared to granulated cell types, the cytoplasmic organization of stellate cells is not complex. Mitochondria, smooth and granular endoplasmic reticulum, Golgi membranes, ribosomes, dense bodies and lipid droplets are distributed throughout the cytoplasm, but not in great numbers. Nuclear chromatin is uniformly distributed. A nucleolus may or may not be evident. The ultrastructural features of the stellate cells are in many respects unchanged from birth to adulthood. An exception is in one-to-two-day-old neonates when in some stellate cells the quantity of cytoplasmic filaments appears increased and there is hyperplasia of the endoplasmic reticulum and Golgi membranes. A similar hyperplasia of these stellate cell organelles can be produced experimentally in adult rabbits by administration of Metopirone. Though the morphological evidence supports a structural or metabolically supportive function for the stellate cell, an additional role as the possible source of adrenocorticotrophic hormone is also discussed.     

Occurrence of colloid-containing follicles and ciliated cysts in the hypophysial pars tuberalis from guinea pigs of various ages

Colloid-containing follicles and ciliated cysts in the hypophysial pars tuberalis of guinea pigs at various ages ranging from 5 days to 36 months were examined by periodic acid-Schiff (PAS) reaction, immunohistochemistry, and electron microscopy. The follicles storning PAS-positive colloid were encountered in the pars tuberalis of all guinea pigs examined, although only a few were present in young animals. The follicles gradually increased in number with age. The largest number of follicles was found in the senile male group: 141.3 ± 11.9, about 10 times the number in the 5-day-old male group. The follicles were scattered throughout the entire length of the pars tuberalis. Follicles with enlarged luminal cavities were concentrated in the ventral caudal region surrounding the infundibular stem and merges with the pars distalis. Three different types of follicles were found by electron microscopy:(1) those surrounded by nongranulated follicular cells that may correspond to the stellate-follicular cells in the pars distalis, (2) those surrounded by specific cells that were packed with vesicular inclusions, and (3) those surrounded by granulated cells that may be gonadotropes. In the follicles lined by nongranulated follicular cells, long, prominent microvilli and cytoplasmic processes protruding into the lumen and invaginations of colloid were often observed at the apical cell region. The follicles lined by the specific cells having numerous vesicles were localized only in the ventral caudal portion. The vesicles ranged from 200 to 700 nm in diameter, and the outer surface of their limiting membrane was partly studded with ribosomes. Gonadotropes immunoreactive to the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) antisera were distributed in the guinea pig pars tuberalis. As well as the typical follicles described above, the follicles composed solely of granulated cells showed microvilli protruding into the cavities and junctional complexes at the apical lateral surface. They stored heterogeneous materials in the lumina. Some secretory granules gave the appearance of being discharged into the lumen. Ciliated cysts were frequently observed in the pars tuberalis; their incidence was 71.7%. The ciliated cysts were much larger than colloid-containing follicles. Cystic cavities were only partly filled with heterogeneous materials showing colloid-like, flocculent, and granular features.     

Retinoid-induced epidermal hyperplasia in human skin organ culture: inhibition with soy extract and soy isoflavones

Organ cultures of human skin were incubated for 8 days with 1 microg/ml 14-all trans retinoic acid (14-all trans RA) and concomitantly treated with varying concentrations of soy extract. The epidermis of organ cultures treated with 14-all trans RA alone underwent a hyperplastic response. In cultures treated with a combination of 14-all trans RA and soy extract (4-40 microg/ml), hyperplasia was reduced by 16-41%. The same concentrations of soy extract that reduced epidermal hyperplasia in organ culture also suppressed proliferation of rapidly growing keratinocytes in monolayer culture (approximately 25% reduction at 20 and 40 microg/ml). On the other hand, soy extract did not further inhibit proliferation of quiescent keratinocytes; rather, it stimulated growth (50-52% increase relative to control). When dermal fibroblasts were examined for a response to soy extract (i.e., proliferation and synthesis of type I procollagen), both responses were stimulated (proliferation: 75% increase and collagen production 114% increase relative to control). Genistein, the major isoflavone in extracts of soy also inhibited epidermal hyperplasia in organ culture (34-40% reduction relative to control). The same concentrations that reduced epidermal hyperplasia (0.5-1.0 microg/ml) also inhibited keratinocyte proliferation in monolayer culture but had little effect on fibroblast growth. Two other isoflavones (daidzein and glycetein) were also inhibitory, but were less effective than genistein. Taken together, these data suggest that use of soy extract or its constituent isoflavones in conjunction with 14-all trans RA may provide a way to mitigate unwanted epidermal effects of topical retinoid therapy without compromising beneficial retinoid effects in the dermis.     

三叶因子3在大鼠腺垂体嗜色细胞中的定位

目的探讨三叶因子3(TFF3)在腺垂体远侧部嗜酸性细胞和嗜碱性细胞中的表达,明确TFF3在远侧部的分布。方法采用相邻切片的免疫组织化学染色,在相邻切片上分别显示TFF3/生长激素(GH)、TFF3/催乳素(PRL)、TFF3/促甲状腺激素(TSH)、TFF3/促肾上腺皮质激素(ACTH)、TFF3/卵泡刺激素(FSH)、TFF3/黄体生成素(LH)的表达。结果 TFF3和各嗜色细胞的免疫反应产物为棕黄色,主要位于细胞质,ACTH免疫阳性信号在胞膜也有表达,主要分布在腺垂体的远侧部。邻片显示TFF3存在于部分GH、PRL、TSH、ACTH、FSH、LH细胞,分别占19.4%、22.4%、9.2%、6.5%、35.7%、8.3%,以FSH最多,PRL、GH次之。结论垂体远侧部TFF3可分别表达于GH、PRL、TSH、ACTH、FSH、LH细胞。     

大鼠实验性腺胃癌过程中脑垂体远侧部FSH细胞的免疫组织化学观察

目的：观察腺垂体ＦＳＨ细胞在大鼠实验性腺胃癌的免疫组织化学变化。材料和方法：ＭＮＮＧ诱发断乳雄性Ｗｉｓｔａｒ大鼠的实验性脾胃癌模型,免疫组织化学、形态计量及图像分析技术。结果：实验性腺胃癌组大鼠脑垂体ＦＳＨ细胞与正常组相比较,免疫反应减弱,面数密度减少（Ｐ〈０．０５）,平均光密度（ＭＯＤ）减弱（Ｐ〈０．０５）。结论：在大鼠实验性胃癌过程中,腺垂体ＦＳＨ阳性细胞数量减少的同时,可能伴有合成和分泌功能     

Morphological and biochemical changes of pituitary gonadotropes in male golden hamsters submitted to short and long photoperiods

Golden hamsters are seasonal breeders, and a pattern of regression-recrudescence in their hypothalamic-pituitary axis is observed when adult animals are exposed to less than 12.5 h daylight for a prolonged period of time. The purpose of the present work was to investigate the possible morphological and biochemical changes of gonadotrope cell population in male golden hamsters submitted to both short (SP) and long photoperiods (LP). Thus, adult male golden hamsters were exposed to SP (6 h light, 18 h darkness) for 8, 16, 22 and 28 weeks or maintained under LP (14 h light, 10 h darkness). Pituitaries were processed using both light and electron microscopy, and serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were assessed by heterologous radioimmunoassay. Volume density [VD = Sigma cell area/reference area (RA)] and cell density (CD = number of cells/RA) of gonadotropes were measured with an image analysis system (Imaging Technology, Software Optimas 5.2). When analyzing the gonadotrope population from animals submitted either to SP or LP, no significant differences were found. At the ultrastructural level, we found a decrease (p < 0.05) in the exocytotic profiles and the individual mean area of secretory granules of both gonadotropes in hamsters maintained under SP for 16 and 22 weeks. Exposure to short days resulted in a decline in serum levels showing a nadir after 16 weeks (p < 0.05). Gonadotropin levels of the hamsters under prolonged exposure to short cycles spontaneously returned to normal values after 22 weeks. In summary, we found a decrease in the ultrastructural and biochemical parameters suggesting an altered release of FSH and LH in male golden hamsters submitted to SP, with a spontaneous recrudescence phase appearing at the end of the study.