نتایج جستجو برای: type a spermatogonia
تعداد نتایج: 13688682 فیلتر نتایج به سال:
BACKGROUND The spermatogonial stem cell (SSC) pool in the testes of non-human primates is poorly defined. METHODS To begin characterizing SSCs in rhesus macaque testes, we employed fluorescence-activated cell sorting (FACS), a xenotransplant bioassay and immunohistochemical methods and correlated our findings with classical descriptions of germ cell nuclear morphology (i.e. A(dark) and A(pale...
background: different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats. objective: in this study we worked out the effect of methoxsalen together with ultraviolent a (uva) radiation on mature balb/c mice spermatogenesis. materials and methods: the ld50 standard was determined 160 mg/kg and the uva dose which causes erythema was calculated 0.046 j...
During normal spermatogenesis, more than half of the germ cells undergo apoptosis, but the physiological significance and molecular mechanisms of this programmed cell death are largely unknown. Because Bcl-2 functions as a death repressor, we have investigated the effect of misexpressing Bcl-2 in spermatogonia in transgenic mice using the human bcl-2 cDNA under the control of the human polypept...
Melatonin has a direct inhibitory effect on the basal and oestradiol-stimulated mitotic activity of primary spermatogonia in the testis of the frog, Rana esculenta. In this study oestradiol was used to induce spermatogonial proliferation to verify the anti-proliferative effect of melatonin. The colchicine metaphase arrest technique was used. The results obtained from in vivo experiments confirm...
In adult rhesus monkeys a two- to threefold increase in the number of spermatogonia was found at Day 75 after 1 Gy of X-irradiation when the animals were pretreated with two intramuscular injections of follicle-stimulating hormone (FSH) each day. Also the percentage of cross-sections of seminiferous tubules showing spermatogonia (repopulation index) was much higher when FSH was given before irr...
BACKGROUND Unilateral orchidectomy in monkeys increases spermatogenesis in the remaining testis in association with elevated follicle-stimulating hormone (FSH) secretion and testicular testosterone. The present study examined the relative importance of FSH and testosterone in driving the primate testis toward its spermatogenic ceiling. METHODS Adult male rhesus monkeys were treated with a gon...
BACKGROUND AND AIMS In mammalian spermatogenesis, glial cell line-derived neurotrophic factor (GDNF) is one of the major Sertoli cell-derived factors which regulates the maintenance of undifferentiated spermatogonia including spermatogonial stem cells (SSCs) through GDNF family receptor α1 (GFRα1). It remains unclear as to when, where and how GDNF molecules are produced and exposed to the GFRα1...
Spermatogonial stem cell (SSC) transplantation has been shown to restore fertility in several species and may have application for treating some cases of male infertility (e.g., secondary to gonadotoxic therapy for cancer). To ensure safety of this fertility preservation strategy, methods are needed to isolate and enrich SSCs from human testis cell suspensions and also remove malignant contamin...
In newts elevated titers of plasma prolactin (PRL), induced by low temperature, cause apoptosis in the penultimatemitotic stage of spermatogonia, and this cell death is suppressed by antiserum against newt PRL, but only during the initial 3 days of exposure (Yazawa et al., 1999). Thus, factors other than PRL must be involved in spermatogonial death. Follicle-stimulating hormone (FSH) may be a p...
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