Browsing by Subject "LH"

Now showing 1 - 4 of 4
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    Effect of estrogenization in the first day of life on the reproductive system in male rats
    (Murcia : F. Hernández, 1994) Limanowski, A.; Miskowiak, B.; Otulakowski, B.
    The aim of the present report was to investigate dynamics of morphological and functional changes in the reproductive system of male rats between 20th and 84th day of life, injected neonatally with a single dose of stilbestrol. Marked reduction in relative weights of testes and accessory sexual glands was demonstrated in various periods of life. This was associated with inhibition of spermatogenesis at the stage of primary spermatocytes and with morphological as well as functional alterations in epididymis? seminal vesicles and ventral prostate. In the serunl, high levels of LH and lowered testosterone levels were demonstrated.
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    Follicle-stimulating hormone promotes nerve growth factor and vascular endothelial growth factor expression in epithelial ovarian cells
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Garrido, Maritza P.; Bruneau, Nicole; Vega, Margarita; Selman, Alberto; Tapia, Julio C.; Romero, Carmen
    Ovarian cancer is the first cause of death for gynecological malignances in developed countries and around 80% correspond to Epithelial Ovarian Cancer (EOC). Overexpression of Nerve Growth Factor (NGF) and its high affinity receptor TRKA are involved in EOC progression, modulating several oncogenic processes such as angiogenesis by the increase of Vascular Endothelial Growth Factor (VEGF). FSH receptors (FSH-R) are present in EOC, but their changes and contribution during EOC progression are still not thoroughly known. The aims of this study were to evaluate the abundance of FSH receptors during EOC differentiation and to determine whether FSH modulates oncoproteins such as NGF and VEGF in ovarian cells. FSH-R expression in EOC tissues and cell lines (A2780, poorly differentiated EOC cells and HOSE, non-tumoral ovarian surface epithelial cells) were measured by RT- PCR and laser capture of epithelial cells from EOC samples by qPCR. FSH-R protein levels were evaluated by immunohisto/cytochemistry. Additionally, ovarian explants and ovarian cell lines were stimulated with FSH and/or FSH-R inhibitor to assess NGF and VEGF mRNA and protein levels. The results showed that FSH-R levels decreased during loss of EOC cell differentiation, nevertheless these receptors are still present in poorly differentiated EOC. FSH increased NGF expression in ovarian cells, which was prevented using a FSH-R inhibitor. Similarly, in ovarian cancer explants, FSH increased NGF and VEGF mRNA, as well as NGF protein levels. These results suggest that FSH would display a key role not only in initial stages of EOC, but also in late stages of this disease, by modulation of NGF and VEGF levels in EOC cells
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    ImmunohistochemicaI-morphometric study of the LH-adenohypophyseal cells following chronic treatment with met-enkephalin
    (Murcia : F. Hernández, 1994) Rubio, M.; Sanchez, F.; Carretero, J.; Riesco, J. M.; Cabo, L.; Vazquez, R.
    In order to test the possible effect of chronic treatment with met-enkephalin upon the LHadenohypophyseal cells, an imrnunohistochemicalmorphometric study was carried out in rats of both sexes receiving a daily dose of 40 pg of met-enkephalin intramuscularly over 15 days. Following the administration of the opioid, a drastic decrease in the cellular, cytoplasmic and nuclear areas when compared to the normal and control animals was detected. Morphologically, the main finding in males was the appearance of irregularly-shaped pseudovacuolated cells. On the other hand, in females a decrease in the intensity of reaction was found. These results strongly suggest a decrease in the activity of the LH-adenohypophyseal cells following chronic administration of met-enkephalin.
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    Luteinizing hormone on Leydig cell structure and function
    (Murcia : F. Hernández, 1997) Mendis-Handagama, S.M.L.C.
    The effects of luteinizing hormone (LH) and human chorionic gonadotrophic hormone (hCG) on Leydig cell structure and function are reviewed in this paper under two main headings; responses to LH and hCG stimulation and responses to LH deprivation. With acute LH stimulation, up to 2 hours following the LH injection, there was no change in the volume of a Leydig cell. However, Leydig cell peroxisomal volume and intraperoxisomal SCP2 content showed a rapid and transient change. These changes can be considered to be specific because: i) no other Leydig cell organelle including smooth endoplasmic reticulum (SER) showed such a change, and ii) only the intraperoxisomal SCP but not catalase (a marker enryme for peroxisome~ showed such a change within 30 minutes of LH stimulation. As these changes occurred prior to the peak testosterone levels following this treatment, it is suggested that SCP2 and peroxisomes may have an association with testosterone biosynthesis prior to cholesterol transport into mitochondria. With LH or hCG stimulation for longer periods, i.e. one day or more, the same morphological changes are produced in Leydig cells irrespective of the age of the species, dosage of LH or hCG, and with single or multiple doses. These changes include, Leydig cell hypertrophy andlor hyperplasia, increase in the cellular organelle content (mostly SER and mitochondria) and depletion of lipid droplets. In addition, a recent study showed that Leydig cell peroxisomal volume, SCP2 content, the amount of intraperoxisomal SCP2 and testosterone secretory capacity were also significantly increased in response to chronic LH treatment. The effects of LH deprivation by whatever means (e.g. hypophysectomy, with testosterone and 17B-estradiol Silastic implants, LH antisera) on Leydig cell structure and function is generally described as opposite to those observed following LH or hCG stimulation. These include Leydig cell hypotrophy and hypoplasia, reductions in the cytoplasmic organelle content in general and specific reductions in SER and peroxisomal volumes, reductions in total catalase and Ofíprint requests to: Dr. S.M.L. Chamindrani Mendis-Handagama, Department of Animal Science, College of Veterinary Medicine, The Universiiy of Tennessee, Knoxville, Tennessee 37996, USA. SCP2 in Leydig cells together with reductions in the intraperoxisomal SCP2 content in Leydig cells and their testosterone secretory capacity.