79 research outputs found
Heteropterys Tomentosa (a. Juss.) Infusion Counteracts Cyclosporin A Side Effects On The Ventral Prostate.
Cyclosporin A (CsA) is an immunosuppressive drug widely used in treatment of auto-immune diseases or after organ transplants. However, several side effects are commonly associated with CsA long term intake, some regarding to loss of reproductive organ function due to oxidative damage. Considering that phytotherapy is an important tool often used against oxidative stress, we would like to describe the beneficial effects of Heteropterys tomentosa intake to minimize the damage caused by CsA to the ventral prostate tissue of Wistar rats under laboratorial conditions. Thirty adult Wistar rats (Rattus norvegicus albinus) were divided into: control group (water); CsA group (Cyclosporin A); Ht group (H. tomentosa infusion) and CsA + Ht group (CsA and H. tomentosa infusion). Plasmic levels of hepatotoxicity markers, triglycerides, cholesterol and glucose were quantified. The ventral prostate tissue was analyzed under light microscopy, using stereological, morphometrical and immunohistochemical techniques. H. tomentosa did not cause any alterations either of the plasmic parameters or of the ventral prostate structure. CsA caused alterations of GOT, total and indirect bilirubin, cholesterol, triglycerides and glucose levels in the plasma; CsA-treated rats showed alterations of the ventral prostate tissue. There were no alterations regarding the plasma levels of GOT, triglycerides and glucose of CsA + Ht animals. The same group also showed normalization of most of the parameters analyzed on the ventral prostate tissue when compared to the CsA group. The treatments did not alter the pattern of AR expression or the apoptotic index of the ventral prostate epithelium. The results suggest a protective action of the H. tomentosa infusion against the side effects of CsA on the ventral prostate tissue, which could also be observed with plasmic biochemical parameters.133
Effects of myenteric denervation on extracellular matrix fibers and mast cell distribution in normal stomach and gastric lesions
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Background\ud
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In this study the effect of myenteric denervation induced by benzalconium chloride (BAC) on distribution of fibrillar components of extracellular matrix (ECM) and inflammatory cells was investigated in gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Rats were divided in four experimental groups: non-denervated (I) and denervated stomach (II) without MNNG treatment; non-denervated (III) and denervated stomachs (IV) treated with MNNG. For histopathological, histochemical and stereological analysis, sections of gastric fragments were stained with Hematoxylin-Eosin, Picrosirius-Hematoxylin, Gomori reticulin, Weigert's Resorcin-Fuchsin, Toluidine Blue and Alcian-Blue/Safranin (AB-SAF).\ud
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Results\ud
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BAC denervation causes an increase in the frequency of reticular and elastic fibers in the denervated (group II) compared to the non-denervated stomachs (group I). The treatment of the animals with MNNG induced the development of adenocarcinomas in non-denervated and denervated stomachs (groups III and IV, respectively) with a notable increase in the relative volume of the stroma, the frequency of reticular fibers and the inflammatory infiltrate that was more intense in group IV. An increase in the frequency of elastic fibers was observed in adenocarcinomas of denervated (group IV) compared to the non-denervated stomachs (group III) that showed degradation of these fibers. The development of lesions (groups III and IV) was also associated with an increase in the mast cell population, especially AB and AB-SAF positives, the latter mainly in the denervated group IV.\ud
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Conclusions\ud
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The results show a strong association in the morphological alteration of the ECM fibrillar components, the increased density of mast cells and the development of tumors induced by MNNG in the non-denervated rat stomach or denervated by BAC. This suggests that the study of extracellular and intracellular components of tumor microenvironment contributes to understanding of tumor biology by action of myenteric denervation.We are grateful to Domingos Zanchetta Netto and Luiz Roberto Falleiros-Jr for technical assistance. CFE and CBM were supported by Fundação de Amparo á Pesquisa - FAPESP (grants 08/05722-6 and 03/10634-5, respectively) and SRT by Conselho Nacional de Desenvolvimento Cientifico e Tecnológico - CNPq (grants 301111/05-7 and 300163/2008-8).We are grateful to Domingos Zanchetta Netto and Luiz Roberto FalleirosJr for technical assistance. CFE and CBM were supported by Fundação de Amparo á Pesquisa FAPESP (grants 08/057226 and 03/106345, respectively) and SRT by Conselho Nacional de Desenvolvimento Cientifico e Tecnológico CNPq (grants 301111/057 and 300163/20088)
Modulação androgênica e estrogênica na próstata: uma abordagem em modelos experimentais de roedores com enfoque na biologia estrutural
Ultrastructural characteristics of the spermatogenesis during the four phases of the annual reproductive cycle of the black myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae)
Myotis nigricans is an endemic species of vespertilionid bat, from the Neotropical region, that resembles temperate zone bats in their reproductive cycle; presenting an annual reproductive cycle with two periods of testicular regression, which are not linked to the apoptotic process and seems to be not directly linked to any seasonal abiotic variation. Thus, this study aimed to ultrastructurally evaluate their reproductive cycle. The process of testicular regression could be divided into four periods: active; regressing; regressed and recrudescence; with all presenting distinct characteristics. The active period was similar to that of other bats, presenting the complete occurrence of spermatogenesis, with three main types of spermatogonia (Ad, Ap, and B) and 12 steps in spermatid differentiation; however, it differed in having the outer dense fibers 1, 5, 6, and 9 larger than the others. These three types of spermatogonia undergo considerable morphologic changes from regressing to the regressed period, and in the recrudescence, they return to the basic morphology, which reactivates spermatogenesis. In conclusion, our study described the process of spermatogenesis, the ultrastructure of the spermatozoa and the distinct morphologic variations in the ultrastructure of the testicular cells of M. nigricans during the four different periods of its annual reproductive cycle. Microsc. Res. Tech., 76:1035-1049, 2013. © 2013 Wiley Periodicals, Inc
Heterófilos em sangue periférico de Phrynops geoffroanus (Testudines: Chelidae) de ambiente urbano na região noroeste do estado de São Paulo Heterophils in peripheral blood of Phrynops geoffroanus (Testudines: Chelidae) from an urban environment of the northeast region of São Paulo State
The mongolian gerbil (Meriones unguiculatus) as a model for inflammation-promoted prostate carcinogenesis
One of the recognized issues in prostate cancer research is the lack of animal models allowing the research of pathological, biochemical, and genetic factors in immunocompetent animals. Our research group has successfully employed the gerbil in several studies for prostate diseases. In the present work, we aimed to analyze the effect of chronic bacterial inflammation on N-methyl-N-nitrosourea (MNU)-induced prostate carcinogenesis in gerbils. Histopathological assessment of the prostatic complex revealed that treatment combinations with MNU plus testosterone or bacterial infection resulted in a promotion of prostate cancer, with bacterial inflammation being more effective in increasing premalignant and malignant tissular alterations than testosterone in the prostate. Furthermore, chronic bacterial inflammation itself induced premalignant lesions in the ventral lobe and increased their frequency in the dorsolateral lobe as well as malignant lesions in the ventral prostate. These animals showed a rich inflammatory microenvironment, characterized as intraluminal and periductal foci. These data indicate that chronic inflammation induced by Escherichia coli acts as a potent tumor promoter, in the early stages of carcinogenesis in the gerbil, in line with the hypothesis of inflammation supporting several steps of tumor development in the prostate gland.Fil: Quintar, Amado Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba;Facultad de Ciencias Médicas;Cátedra de Bioquímica Molecular; ; ArgentinaFil: Gonçalves, Bianca F.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Taboga, Sebastião R.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Maldonado, Cristina Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba;Facultad de Ciencias Médicas;Cátedra de Bioquímica Molecular; ; Argentin
Annual reproductive cycle of males of the flat-faced fruit-eating bat, Artibeus planirostris (Chiroptera: Phyllostomidae)
Artibeus planirostris is an endemic species of Phyllostomid bat from the Neotropical region. Some studies have indicated that it exhibits seasonal bimodal polyestry; however, others postulate that it may be able to produce young at any time during the year. Thus, the aim of this study was to evaluate the annual variations in testicular and epididymal parameters of this species in southeast Brazil and try to understand how the reproduction of this species is regulated in this environment. Sixty mature male specimens, collected between June 2009 and May 2010, were submitted to morphometric and immunohistochemical analysis. Our study showed that A. planirostris presented a continuously active pattern of spermatogenesis throughout the year, presenting spermatozoa inside its cauda epididymis in all months, but with two pronounced peaks of spermatogenic production, one in September and other in February. We propose that the males developed these two peaks in order to produce sufficient sperm for the reproduction in a harem system and to synchronize with the female reproductive cycle, which had a bimodal polyestric pattern. Control of this variation is directly linked to the expression of the androgen receptor (AR) in Sertoli cells and to serum testosterone levels, which appear to synchronize to establish these two peaks. In the months preceding the two peaks, the testis have a higher expression of the AR, which possibly stimulates the increase in PCNA, and drives a gradual increase in the testicular parameters. Taken together the results suggest that if sperm storage happens in this species, it is of short duration. © 2013 Elsevier Inc
High Doses Of Dexamethasone Induce Increased Beta-cell Proliferation In Pancreatic Rat Islets.
Activation of insulin signaling and cell cycle intermediates is required for adult beta-cell proliferation. Here, we report a model to study beta-cell proliferation in living rats by administering three different doses of dexamethasone (0.1, 0.5, and 1.0 mg/kg ip, DEX 0.1, DEX 0.5, and DEX 1.0, respectively) for 5 days. Insulin sensitivity, insulin secretion, and histomorphometric data were investigated. Western blotting was used to analyze the levels of proteins related to the control of beta-cell growth. DEX 1.0 rats, which present moderate hyperglycemia and marked hyperinsulinemia, exhibited a 5.1-fold increase in beta-cell proliferation and an increase (17%) in beta-cell size, with significant increase in beta-cell mass, compared with control rats. The hyperinsulinemic but euglycemic DEX 0.5 rats also showed a significant 3.6-fold increase in beta-cell proliferation. However, DEX 0.1 rats, which exhibited the lowest degree of insulin resistance, compensate for insulin demand by improving only islet function. Activation of the insulin receptor substrate 2/phosphatidylinositol 3-kinase/serine-threonine kinase/ribosomal protein S6 kinase pathway, as well as protein retinoblastoma in islets from DEX 1.0 and DEX 0.5, but not in DEX 0.1, rats was also observed. Therefore, increasing doses of dexamethasone induce three different degrees of insulin requirement in living rats, serving as a model to investigate compensatory beta-cell alterations. Augmented beta-cell mass involves beta-cell hyperplasia and, to a lower extent, beta-cell hypertrophy. We suggest that alterations in circulating insulin and, to a lesser extent, glucose levels could be the major stimuli for beta-cell proliferation in the dexamethasone-induced insulin resistance.296E681-
High doses of dexamethasone induce increased β-cell proliferation in pancreatic rat islets
Activation of insulin signaling and cell cycle intermediates is required for adult β-cell proliferation. Here, we report a model to study β-cell proliferation in living rats by administering three different doses of dexamethasone (0.1, 0.5, and 1.0 mg/kg ip, DEX 0.1, DEX 0.5, and DEX 1.0, respectively) for 5 days. Insulin sensitivity, insulin secretion, and histomorphometric data were investigated. Western blotting was used to analyze the levels of proteins related to the control of β-cell growth. DEX 1.0 rats, which present moderate hyperglycemia and marked hyperinsulinemia, exhibited a 5.1-fold increase in β-cell proliferation and an increase (17%) in β-cell size, with significant increase in β-cell mass, compared with control rats. The hyperinsulinemic but euglycemic DEX 0.5 rats also showed a significant 3.6-fold increase in β-cell proliferation. However, DEX 0.1 rats, which exhibited the lowest degree of insulin resistance, compensate for insulin demand by improving only islet function. Activation of the insulin receptor substrate 2/phosphatidylinositol 3-kinase/serine-threonine kinase/ribosomal protein S6 kinase pathway, as well as protein retinoblastoma in islets from DEX 1.0 and DEX 0.5, but not in DEX 0.1, rats was also observed. Therefore, increasing doses of dexamethasone induce three different degrees of insulin requirement in living rats, serving as a model to investigate compensatory β-cell alterations. Augmented β-cell mass involves β-cell hyperplasia and, to a lower extent, β-cell hypertrophy. We suggest that alterations in circulating insulin and, to a lesser extent, glucose levels could be the major stimuli for β-cell proliferation in the dexamethasone-induced insulin resistance2964E681E689CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão te
Progesterone As A Morphological Regulatory Factor Of The Male And Female Gerbil Prostate.
Testosterone (T) and oestrogen are the main active steroid hormones in the male and female reproductive system respectively. In female rodents progesterone (P4), together with testosterone and oestrogen, has an essential role in the regulation of the oestrous cycle, which influences the prostate physiology through their oscillations. In this work we investigated how the male and female prostate gland of Mongolian gerbils responds to surgical castration at the start of puberty and what are the effects of T, oestradiol (E2) and P4 replacement, using both quantitative and qualitative methods. We also examined the location of the main steroid receptors present in the prostate. In the castrated animals of both sexes an intense glandular regression, along with disorganization of the stromal compartment, and abundant hyperplasia was observed. The replacement of P4 secured a mild recovery of the glandular morphology, inducing the growth of secretory cells and restoring the androgen receptor (AR) cells. The administration of P4 and E2 eliminated epithelial hyperplasia and intensified gland hypertrophy, favouring the emergence of prostatic intraepithelial neoplasia (PIN). In animals treated with T and P4, even though there are some inflammatory foci and other lesions, the prostate gland revealed morphology closer to that of control animals. In summary, through the administration of P4, we could demonstrate that this hormone has anabolic characteristics, promoting hyperplasia and hypertrophy, mainly in the epithelial compartment. When combined with E2 and T, there is an accentuation of glandular hypertrophy that interrupts the development of hyperplasia and ensures the presence of a less dysplastic glandular morphology.94373-8
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