Leydig Cell
Mostrando 25-36 de 117 artigos, teses e dissertações.
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25. Avaliação funcional das celulas de Leydig e de Sertoli em 24 casos de ambiguidade genital com cariotipo 46,XY
The investigation of the origin of sex ambiguity is a very complex matter. Sex differentiation is dependent upon the action of two testicular hormones: testosterone and anti-Müllerian hormone (AMH). Although testicular function has traditionally been assessed only by examining the steroidogenic capacity of Leydig cells and spermatogenesis, it has recently b
Publicado em: 1999
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26. Desert Hedgehog/Patched 1 signaling specifies fetal Leydig cell fate in testis organogenesis
Establishment of the steroid-producing Leydig cell lineage is an event downstream of Sry that is critical for masculinization of mammalian embryos. Neither the origin of fetal Leydig cell precursors nor the signaling pathway that specifies the Leydig cell lineage is known. Based on the sex-specific expression patterns of Desert Hedgehog (Dhh) and its recepto
Cold Spring Harbor Laboratory Press.
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27. Differentiation of adult-type Leydig cells occurs in gonadotrophin-deficient mice
During mammalian testis development distinct generations of fetal and adult Leydig cells arise. Luteinising hormone (LH) is required for normal adult Leydig cell function and for the establishment of normal adult Leydig cell number but its role in the process of adult Leydig cell differentiation has remained uncertain. In this study we have examined adult Le
BioMed Central.
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28. Stimulation of TM3 Leydig cell proliferation via GABAA receptors: A new role for testicular GABA
The neurotransmitter gamma-aminobutyric acid (GABA) and subtypes of GABA receptors were recently identified in adult testes. Since adult Leydig cells possess both the GABA biosynthetic enzyme glutamate decarboxylase (GAD), as well as GABAA and GABAB receptors, it is possible that GABA may act as auto-/paracrine molecule to regulate Leydig cell function. The
BioMed Central.
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29. Long-term suppression of Leydig cell steroidogenesis prevents Leydig cell aging
Male aging is accompanied by reduced testosterone production by the Leydig cells, the testosterone-producing cells of the testis. The mechanism by which this occurs is unknown. Based on the observations that reactive oxygen is capable of damaging components of the steroidogenic pathway and that reactive oxygen is produced during steroidogenesis itself, we hy
The National Academy of Sciences.
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30. Receptors for anti-Müllerian hormone on Leydig cells are responsible for its effects on steroidogenesis and cell differentiation
Strong overexpression of anti-Müllerian hormone (AMH) in transgenic mice leads to incomplete fetal virilization and decreased serum testosterone in the adult. Conversely, AMH-deficient mice exhibit Leydig cell hyperplasia. To probe the mechanism of action of AMH on Leydig cell steroidogenesis, we have studied the expression of mRNA for steroidogenic protein
The National Academy of Sciences.
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31. Ultrastructure of Leydig cells in human ageing testes.
Ultrastructural study of Leydig cells in elderly men revealed the following Leydig cell types: (1) ultrastructurally normal Leydig cells (46.2%); (2) Leydig cells either with multiple cytoplasmic or intranuclear Reinke crystals or with numerous para-crystalline inclusions (6.1%); (3) multivacuolated Leydig cells with the cytoplasm almost filled by lipid drop
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32. Cytomegalovirus infection of murine testicular interstitial Leydig cells.
We studied the susceptibility of mouse testicular interstitial Leydig cells to cytomegalovirus both in vivo and in vitro. The in vivo studies included intratesticular and intraperitoneal infection of 6-week-old mice with murine cytomegalovirus (MCMV); the in vitro studies involved an MCMV-Leydig cell interaction using a Leydig tumor cell line (I-10). MCMV-sp
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33. Inhibition of Cyclooxygenase-2 Down-regulates Aromatase Activity and Decreases Proliferation of Leydig Tumor Cells*
Our recent studies have revealed that estrogens stimulate an autocrine mechanism determining Leydig tumor cell proliferation. Estrogen overproduction is due to an elevated steroidogenic factor-1 (SF-1) expression and cAMP-response element-binding protein (CREB) phosphorylation, both inducing aromatase overexpression. Although we have shown that increased SF-
American Society for Biochemistry and Molecular Biology.
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34. Construction of a Leydig cell line synthesizing testosterone under gonadotropin stimulation: a complex endocrine function immortalized by cell hybridization.
Hybridization between a mouse Leydig tumor cell line, MA-10, which produces cyclic AMP and progesterone under human chorionic gonadotropin (hCG) stimulation, and freshly isolated mouse Leydig cells gave rise to 54 hybrid clones, one of which, LK17, was capable of hCG-stimulated testosterone production. Subcloning of this hybrid resulted in the emergence of a
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35. Mumps Virus Decreases Testosterone Production and Gamma Interferon-Induced Protein 10 Secretion by Human Leydig Cells
Mumps virus is responsible for sterility. Here, we show that the mumps virus infects Leydig cells in vitro and totally inhibits testosterone secretion and that ribavirin in mumps virus-infected Leydig cell cultures completely restores testosterone production. Moreover, we show that gamma interferon-induced protein 10 (IP-10) is highly expressed by mumps viru
American Society for Microbiology.
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36. Gonadotropin binding and stimulation of steroidogenesis in Leydig tumor cells
Testicular tumors are generally characterized by a loss of responsiveness to gonadotropins. The M5480 Leydig cell tumor is unusual, if not unique, in that it responds to human choriogonadotropin and to lutropin via increased steroidogenesis. This report describes the identification of two variants of the original M5480 tumor that have altered steroid output