共查询到20条相似文献,搜索用时 953 毫秒
1.
M. Murakami M. Hamasaki S. Okita J. Abe 《Cellular and molecular life sciences : CMLS》1979,35(8):1099-1101
Summary The SEM observation of the basal surface of the contractile cells in the boundary tissue of the seminiferous tubule of the rat has revealed that the contractile cells are extremely flat, vary in shape from rectangular to hexagonal, and are arranged close to each other, in the fashion of a tiled floor, around the seminiferous epithelium. 相似文献
2.
Summary The appearance of the Sertoli cells in cytological smears of testes with depopulation of the seminiferous epithelium is described. The mean values of the lengths and widths of the Sertoli cell nuclei in smears differed significantly between the depopulation and the control group (p<0.01). 相似文献
3.
The appearance of the Sertoli cells in cytological smears of tests with depopulation of the seminiferous epithelium is described. The mean values of the lengths and widths of the Sertoli cell nuclei in smears differed significantly between the depopulation and the control group (p < 0.01). 相似文献
4.
B Walles U Gr?schel-Stewart P Kannisto C Owman N O Sj?berg K Unsicker 《Experientia》1990,46(7):682-683
Actin- and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls. 相似文献
5.
The toxic effect of various doses of ochratoxin A on the rat testis was investigated after a single intratesticular injection. At time of sacrifice (day 10) degenerating changes occur in the testicular tissues: seminiferous tubules dilatation, cytolysis of the seminiferous epithelium, hyperplasia of the interstitial tissue, vascular thrombosis. The relations between the blood supply disturbances and the observed lesions are discussed. 相似文献
6.
Summary The toxic effect of various doses of ochratoxin A on the rat testis was investigated after a single intratesticular injection. At time of sacrifice (day 10) degenerating changes occur in the testicular tissues: seminiferous tubules dilatation, cytolysis of the seminiferous epithelium, hyperplasia of the interstitial tissue, vascular thrombosis. The relations between the blood supply disturbances and the observed lesions are discussed. 相似文献
7.
B. Walles U. Gröschel-Stewart P. Kannisto Ch. Owman N. -O. Sjöberg K. Unsicker 《Cellular and molecular life sciences : CMLS》1990,46(7):682-683
Summary Actin-and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.This work was supported by the Swedish Medical Research Council, grant No. 14X-732/5680. 相似文献
8.
At the end of mitosis, daughter cells are separated from each other by cytokinesis. This process involves equal partitioning
and segregation of cytoplasm between the two cells. Despite years of study, the mechanism driving cytokinesis in animal cells
is not fully understood. Actin and myosin are major components of the contractile ring, the structure at the equator between
the dividing cells that provides the force necessary to constrict the cytoplasm. Despite this, there are also tantalizing
results suggesting that cytokinesis can occur in the absence of myosin. It is unclear what the roles are of the few other
contractile ring components identified to date. While it has been difficult to identify important proteins involved in cytokinesis,
it has been even more challenging to pinpoint the regulatory mechanisms that govern this vital process. Cytokinesis must be
precisely controlled both spatially and temporally; potential regulators of these parameters are just beginning to be identified.
This review discusses the recent progress in our understanding of cytokinesis in animal cells and the mechanisms that may
regulate it.
Received 24 August 1998; received after revision 9 October 1998; accepted 9 October 1998 相似文献
9.
Marco G. Alves Luís Rato Rui A. Carvalho Paula I. Moreira Sílvia Socorro Pedro F. Oliveira 《Cellular and molecular life sciences : CMLS》2013,70(5):777-793
Hormonal regulation is essential to spermatogenesis. Sertoli cells (SCs) have functions that reach far beyond the physical support of germ cells, as they are responsible for creating the adequate ionic and metabolic environment for germ cell development. Thus, much attention has been given to the metabolic functioning of SCs. During spermatogenesis, germ cells are provided with suitable metabolic substrates, in a set of events mediated by SCs. Multiple signaling cascades regulate SC function and several of these signaling pathways are hormone-dependent and cell-specific. Within the seminiferous tubules, only SCs possess receptors for some hormones rendering them major targets for the hormonal signaling that regulates spermatogenesis. Although the mechanisms by which SCs fulfill their own and germ cells metabolic needs are mostly studied in vitro, SC metabolism is unquestionably a regulation point for germ cell development and the hormonal control of these processes is required for a normal spermatogenesis. 相似文献
10.
Stamenović D 《Cellular and molecular life sciences : CMLS》2008,65(22):3592-3605
Rheological properties of living cells determine how cells interact with their mechanical microenvironment and influence their
physiological functions. Numerous experimental studies have show that mechanical contractile stress borne by the cytoskeleton
and weak power-law viscoelasticity are governing principles of cell rheology, and that the controlling physics is at the level
of integrative cytoskeletal lattice properties. Based on these observations, two concepts have emerged as leading models of
cytoskeletal mechanics. One is the tensegrity model, which explains the role of the contractile stress in cytoskeletal mechanics,
and the other is the soft glass rheology model, which explains the weak power-law viscoelasticity of cells. While these two
models are conceptually disparate, the phenomena that they describe are often closely associated in living cells for reasons
that are largely unknown. In this review, we discuss current understanding of cell rheology by emphasizing the underlying
biophysical mechanism and critically evaluating the existing rheological models.
Received 25 May 2008; received after revision 19 June 2008; accepted 1 July 2008 相似文献
11.
Chlorpromazine and trifluoperazine HCl, antipsychotic drugs known to bind to calmodulin, reversibly inhibited elevation of neural folds by interfering with the contractile activity of apical microfilament bundles in developing chick neuroepithelial cells. 相似文献
12.
Vagal tone is responsible for the heterogeneous reactivity of atrial and ventricular contractile tissues to quinidine. Acetylcholine may make atrial cells more sensitive to the effects of quinidine. 相似文献
13.
Farges J. P. Lièvre M. Ollagnier M. Faucon G. 《Cellular and molecular life sciences : CMLS》1978,34(5):631-632
Cellular and Molecular Life Sciences - Vagal tone is responsible for the heterogeneous reactivity of atrial and ventricular contractile tissues to quinidine. Acetylcholine may make atrial cells... 相似文献
14.
Development of the myocardial contractile system 总被引:4,自引:0,他引:4
Recent studies regarding developmental changes in the myocardial contractile system from fetal, newborn, and adult animals are reviewed. From the data obtained so far, we conclude that in the early fetus myocardial contraction is mainly dependent on Ca which enters via the sarcolemma. Ca release from the sarcoplasmic reticulum is minimal. The role of the sarcoplasmic reticulum as a source of contractile Ca increases and the role of Ca influx across the sarcolemma in contractile system decreases with development. 相似文献
15.
Enumeration of different types of spermatogonia, following a single i.p. administration of different doses of ethyl methanesulfonate in mice, showed a survival of A1-A4 and in spermatogonia is markedly reduced due to cell killing while the remaining types of spermatogonia were affected marginally. The cell killing effect was dose-dependent, and replenishment of these cells was observed by the end of one cycle of the seminiferous epithelium comprising of 8.5 days. 相似文献
16.
R. G. Nagele J. F. Pietrolungo H. Lee 《Cellular and molecular life sciences : CMLS》1981,37(3):304-306
Summary Coated vesicles were found to accumulate Ca++ in neuroepithelial cells and may play a role in regulating the contractile activities of apical microfilament bundles during uplifting of neural folds in the chick.This study was supported in part by grants from the Research Council and the Charles and Johanna Busch Memorial Fund of Rutgers University. 相似文献
17.
L. P. Bignold 《Cellular and molecular life sciences : CMLS》1987,43(8):860-868
Summary Diverse cell types, including Amoebae, leukocytes, embryonic cells and tumour cells move about on solid surfaces to accomplish such activities as feeding, bacterial destruction, embryological development and metastasis. Theories of the mechanism of this movement are reviewed and a model is proposed which invokes the existence of specific, laterally mobile, transmembranous structures in the cell membrane, which are reversibly adhesive for both the contractile apparatus of the cell internally, and the substratum externally. By this model, the movement of all these cell types can be explained. 相似文献
18.
Myosin and actin were localized in the adrenal gland, using antibodies against these proteins which were isolated from chicken gizzard. Myosin and actin were preferentially located in vascular walls including endothelial cells and in the capsule. In rat and guinea-pig adrenal cortex, the amount of contractile elements in vascular walls corresponded well to the density of adrenergic nerves as revealed with the glyoxylic acid method. 相似文献
19.
The synthesis and testing of [N5-dimethyl-Gln6]-SP5-11 showed 37 +/- 12% contractile activity relative to SP, and intrinsic efficacy 98 +/- 4%. This finding indicates that the carboxamide groups of the dual Gln5-Cln6 moiety are not equally related with the contractile response of the C-terminal heptapeptide of SP. 相似文献
20.
D. Bhattacharjee T. K. Shetty K. Sundaram 《Cellular and molecular life sciences : CMLS》1979,35(5):630-631
Summary Enumeration of different types of spermatogonia, following a single i.p. administration of different doses of ethyl methanesulfonate in mice, showed that survival of A1–A4 and in spermatogonia is markedly reduced due to cell killing while the remaining types of spermatogonia were affected marginally. The cell killing effect was dose-dependent, and replenishment of these cells was observed by the end of one cycle of the seminiferous epithelium comprising of 8.5 days. 相似文献