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51.
Summary The administration of progesterone to ovariectomized rats induces an increase in the volume density (Vv) of the mitochondria and the appearance of giant mitochondria in the uterine glandular cells. This experimental model, including a stereological analysis, allowed us to investigate and quantify a direct effect of progesterone on a well-defined cellular structure without the intervention of estrogen in a priming phase. Synthetic compounds, promegestone, gestrinone and RU 38486, were tested in this model either in place of progesterone or simultaneously with progesterone. The potent progestomimetic activity of promegestone was confirmed by the proliferation of giant mitochondria and a high Vv value for the mitochondria, the two other compounds being inactive even at higher doses. At lower doses, gestrinone and RU 38486 partially inhibit the action of progesterone and at higher doses they both show a complete antagonist effect by preventing the development of the mitochondria. 相似文献
52.
Immunohistochemical demonstration of alpha-1-antitrypsin in the islet cells of human pancreas 总被引:2,自引:0,他引:2
Summary Using the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level, it has been shown that, in the dipnoan preoptico-hypophysial neurosecretory system, vasotocin and mesotocin are synthesized in separate neurons. In the preoptic nuclei, the perikarya of these two types of neurosecretory neurons are not located preferentially. The two types of neurosecretory perikarya give rise to separate vasotocinergic and mesotocinergic axons, respectively. The dipnoan median eminence and neural lobe contain separate vasotocinergic and mesotocinergic nerve fibres, the general distribution of which is described. In the pars distalis and the pars intermedia of the hypophysis, neurohypophysial hormone-containing nerve fibres have not been found.This investigation was supported by a grant from the Belgian Nationaal Fonds voor Geneeskundig Wetenschappelijk OnderzoekThe authors are greatly indebted to Prof. Dr. Hyder, Department of Zoology, University of Nairobi, Kenya for kindly supplying us with the fixed material used in this study 相似文献
53.
Summary Pituitary glands were examined using reference staining (hematoxylin and eosin, periodic acid-Schiff and alcian blue) and the peroxidase-labeled antibody method, for 1) invading anterior cells in the posterior lobe, 2) intermediate colloid forming follicles, and 3) pars tuberalis cells.The results showed: 1) that the majority of cases possessed invading anterior cells of various amount. Most of these cells were positive for ACTH1–18, ACTH17–39 and -MSH. However, on a few occasions, scattered GH, PRL, FSH, FSH, LH and even TSH cells were also present. 2) Colloid forming follicular cells were mostly ACTH cells, but also contained occasional other hormone-secreting cells. Hormone negative cells were correlated with salivary type epithelium. Well established acinic type salivary glands and ciliated epithelium were negative for any hormones immunohistochemically. 3) Pars tuberalis cells were predominantly gonadotrophs but also included TSH and ACTH cells. Some cells appeared to contain both FSH and LH. When these cells underwent squamous metaplasia, they seemed to lose their hormone secreting activity.Part of this study was supported by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, Japan 相似文献
54.
F. Dacheux 《Cell and tissue research》1978,191(2):219-232
Summary Using specific antibodies against subunits of porcine LH and FSH, the pituitary cells which produce these two gonadotrophins were identified in the porcine pituitary at the ultrastructural level using the immunoperoxidase technique. It was clearly shown that most of the gonadotrophic cells are responsible for the production of both FSH and LH. However, some cells, only positive for FSH or LH, indicate that the concentrations of FSH and LH vary from cell to cell. At the ultrastructural level, the FSH/LH cells contain one class of secretory granules strongly positive for both FSH and LH as well as large negatively stained dense bodies. These findings indicate that the one cell-one hormone concept may not apply to gonadotrophic hormones; a FSH/LH cell cannot be distinguished from a LH or a FSH cell without immunocytochemical identification of its hormonal content.Abbreviations p-LH
porcine luteinizing hormone
- p-LH
porcine LH subunit
- p-LH
porcine LH subunit
- p-FSH
porcine follicule stimulating hormone
- p-FSH
porcine FSH subunit
- b-TSH
bovine thyrotropic hormone 相似文献
55.
Philip Coffino Henry R. Bourne Paul A. Insel Kenneth L. Melmon Gary Johnson Josefina Vigne 《In vitro cellular & developmental biology. Plant》1978,14(1):140-145
Summary S49 mouse lymphoma cell mutants, each with a specific defect in its ability to generate or respond to cyclic AMP, have been
isolated. Analysis of the properties of these cells has begun to provide information on complex and significant biologic problems
related to the cyclic AMP system.
Presented in the Opening Symposium on Nutritional Factors and Differentiation at the 28th Annual Meeting of the Tissue Culture
Association, New Orleans, Louisiana, June 6–9, 1977.
The work was supported in part by National Science Foundation Grant BMS 75-06764 and National Institutes of Health Grants
GM 16496 and GM 00001. P.C. is the recipient of National Institutes of Health Research Career Development Award GM 00308.
P. A. I. is an Established Investigator of the American Heart Association. 相似文献
56.
From the mycelium of Penicillium cyclopium a biologically active fraction (P-factor) was isolated, which increases conidiation and the formation of the benzodiazepine alkaloids cyclopenin and cyclopenol. Its activity was determined by measuring the increase of alkaloid formation in strain SM 72. On a preparative scale P-factor preparations were obtained from fermenter-grown hyphae of mutant dev 63 by extraction with water at 120°. P-factor is strongly hydrophilic but it is not a protein. It was active if added during conidiospore germination and early growth phase, causing an acceleration of protein biosynthesis. The action on alkaloid biosynthesis and sporulation is indirect and resembles that of a developmental hormone. 相似文献
57.
Davey K. G., Sommerville R. I. and Rogers W. P. 1982. The effect of ethoxyzolamide, an analogue of insect juvenile hormone, nor-adrenaline and iodine on changes in the optical path difference in the excretory cells and oesophagus during exsheathment in Haemonchus contortus. International Journal for Parasitology12: 509–513. Ethoxyzolamide, an inhibitor of carbonic anhydrase, markedly inhibits exsheathment of Haemonchus when the larvae are subsequently exposed to an exsheathing stimulus of CO2 at 38.5°C. Ethoxyzolamide at 2 × 10?5M does not prevent the increase in optical path difference in the oesophageal region which normally accompanies exsheathment, but markedly inhibits the increase in optical path difference in the excretory cells. An analogue of juvenile hormone (JHA; the methyl ester of 3,7,11 trimethyl-7,11-dichloro-2-dodecenic acid) does not affect the optical path difference in either the oesophagus or the excretory cells of ensheathed worms. When worms are artificially desheathed by exposure to NaOCl, a procedure which mimics the effect of CO2 upon the oesophagus, but which does not affect the excretory cells, subsequent exposure to JHA at room temperature increases the optical path difference in the excretory cells. This increase is enhanced by subsequent incubation of the worms at 38.5°C at 30–60 min and further enhanced when CO2 is present during the incubation at 38.5°C. The stimulation of the excretory cells by JHA is inhibited by ethoxyzolamide at 2 × 10?5M. Noradrenaline at 10?3M has no effect on ensheathed larvae, but causes an increase in optical path difference in the excretory cells of larvae desheathed with NaOCl. This increase is inhibited by ethoxyzolamide. A brief exposure to I2 blocks the response of the excretory cells of both CO2 and JHA, but does not significantly reduce the effect of nor-adrenaline. On the basis of these and previous results, it is proposed that both CO2 and JHA stimulate a hypothetical CO2 receptor which leads to the release of nor-adrenaline. The noradrenaline in turn stimulates, either directly or indirectly, the excretory cells. 相似文献
58.
Jan M.C. Geuns 《Phytochemistry》1978,17(1):1-14
The occurrence of steroid hormones in plants is briefly reviewed. Their effects on plant growth, development and flowering are also considered. 相似文献
59.
Indole-3-acetic acid (IAA) strongly enhanced rooting of etiolated pea epicotyl cuttings while gibberellic acid (GA3) enhanced rooting only slightly. The promoting effects of the hormones appeared not until 14 d after the onset of treatment. When GA3 and IAA were applied together, the initiation of rooting started already after 6 d after onset of treatment. It is suggested that gibberellin plays an important role, in combination with auxin, in the initiation of root formation in Pisum cuttings.Abbreviations IAA
Indole-3-acetic acid
- GA3
Gibberellic acid 相似文献
60.
G. W. Schaeffer 《In vitro cellular & developmental biology. Plant》1977,13(1):31-35
Summary This report describes the culture of Su/Su, Su/su and su/su tissue in vitro. High levels of auxin and low levels of cytokinin
increase growth of the cells. The cells do not need exogenous amino acids for rapid growth and the chlorophyll deficiency
cannot be overcome by amino acids. Reduced levels of auxin and sucrose enhance differentiation, whereas cysteine in the autoclaved
medium inhibit differentiation. The Su chlorophyll mutant of tobacco provides a marker for in vitro studies on photosynthesis
and photorespiration, chloroplast genetics and cell fusion techniques. 相似文献