181 resultados para Anabolic steroids.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Modern protocols to synchronize ovulations for timed artificial insemination and timed embryo transfer that include manipulations in the proestrus period (i.e., between luteolysis and estrus) affect fertility in cattle. Specifically, stimulating pre-ovulatory follicle growth and exposure to estrogens after CL regression increase the proportion of cows pregnant and decrease late embryo mortality. Such effects may be due to both preovulatory actions of estrogens and post-ovulatory actions of progesterone, as concentrations of the later hormone may be changed in response to manipulations conducted during proestrus. In the first portion of this paper we describe strategies used recently to manipulate the proestrus period in protocols for synchronization of ovulation, and to present evidence of their effects on fertility. Manipulations of timing and prominence of sex steroids during the proestrus and early diestrus that affect fertility may act on targets such as the endometrium. This tissue expresses receptors for both estrogens and progesterone and these hormones change endometrial function to support conceptus growth and pregnancy maintenance. However, specific cellular and molecular mechanisms through which fertility is affected via manipulations of the proestrus are poorly understood. In the second portion of this paper we describe a well-defined animal model to study changes in endometrial function induced by manipulations conducted during the proestrus. Such manipulations induced endometrial changes on sex steroid receptors expression, cell proliferation, oxidative metabolism and eicosanoid synthesis in the uterus, but not on glucose transport to uterine lumen. In summary, evidence is accumulating to support a positive role of increasing duration and estrogen availability during the proestrus on fertility to synchronization protocols. Such positive effects may be through changes in endometrial function to stimulate conceptus growth and survival.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

P-glycoprotein is an adenosine triphosphate (ATP)-driven drug efflux carrier responsible for transport of xenobiotics and multiple classes of drugs, many usually use in veterinary medicine. Encoded by MDR1 gene, also referred to as ABCB1, located on chromosome 14, is expressed in many tissues with secretory or excretory functions, such as liver, kidney and intestine, where it limits drug absorption from the gut and promotes drug excretion into the bile and urine of their substrates. In 2001, a 4 base pair gene deletion mutation in the canine MDR1 gene was identified as MDR1-1▲, ABCB1-1▲, MDR1 MDR1 nt 230 (del4) and associated with an non-functional Pglycoprotein. The clinical correlation is the (hyper) sensitivity of certain dogs breeds, mostly collies, to a few classes of drugs such as anticancer drugs (doxorubicin, vincristine, vinblastine), immunosuppressants (cyclosporine), antiparasitic drugs (ivermectin, moxidectin), steroids hormones (aldosterone, cortisol, dexamethasone), antimicrobial agents (tetracycline, doxycycline, levofloxacin, ketoconazole, itraconazole), analgesics (morphine, methadone), antidiarrheals (loperamide), antiepileptic agents (phenothiazine), cardiac drugs (digoxin, diltiazem, verapamil, talinolol) and others. Dogs with homozygous MDR1 nt 230 (del4) MDR1 mutations (MDR1 - / -) have a higher predisposition to intoxication with substrates of P-gp than heterozygous (MDR1 + / -) and these are more likely than dogs homozygous nonmutant (MDR1 +/ +). After the identification of nt230 (del4) mutation, several molecular techniques have been developed for identification of mutant animals as a diagnostic method. The importance of molecular diagnosis is, after the identification of mutant animals, establish treatment protocols safe, exclude this animals from reproduction (genetic selection program) and investigating the history of adverse drugs reactions... (Complete abstract click electronic access below)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Uterine leiomyomas (UL) are benign smooth muscle tumors from myometrium, representing the major indication for hysterectomies and a significant public health problem. Several genetics alterations have been associated with its development and pathogenesis. Although the initial factors that lead to the development of uterine leiomyomas are unclear, there are several evidences showing that ovarian steroids, estrogen and progesterone, are associated with these tumors.Recent reports, however, show others genes related with distinct signalization pathways besides sex hormones, which may be or not activated by these hormones, are associated with uterine leiomyomas development. In this study, the AHR, ESR1, ESR2, PGR and WNT7A gene transcripts expression was evaluated using quantitative real time RT-PCR in 58 UL samples compared to five normal myometrium tissues to explore the hormonal molecular basis of these tumors and associate these expression pattern with clinical and pathological features. The present study showed AHR, ESR1, ESR2, PGR and WNT7A down expression in 60%, 43%, 52%, 60% e 40% of the tumors, respectively, and a significant AHR loss of expression compared with the controls samples (P=0.0130). The comparison between the genes expression values revealed a positive correlation between the AHR and ESR1 transcripts (P<0.0001; r=0.6911) and between the genes ESR1 and WNT7A (P<0.0001; r=0.5655). The expression pattern was compared with clinical and pathological features. The WNT7A gene presented a differential expression pattern between the proliferative and secretory phase of menstrual cycle (P=0.0373) and the AHR and ESR1 genes were differentially expressed between women in reproductive and menopause years (P=0.0267; P=0.0415, respectively). The ESR1 and WNT7A down regulation was statistically ...(Complete abstract click electronic access below)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Currently, Brazil has one of the largest cattle herds worldwide. In order to keep that milk and meat were introduced reproductive biotechnologies such as artificial insemination, embryo transfer and in vitro fertilization. In certain situations the technique may have undesired effect, for example, the production of calve calves due to the very large increase in the gestation period when performed in vitro fertilization. To avoid this problem we perform the induction of labor in order to prevent the product is longer the womb. This induction can also be made in case of diseases that compromise the life of the mother, twin pregnancy an abnormal size calf. The administration of short acting steroids, prostaglandins, association of short acting steroids and prostaglandins and association of short acting steroids, prostaglandins and long-acting corticosteroids are some of the possibilities of induction

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Muscle atrophy is always associated with Dexamethasone (Dexa) treatment, however the mechanisms are not completely understood. This study investigated the effects of Dexa on myostatin and p70S6K protein expression and if previous exercise training (T) can attenuate these effects. Eighty rats were distributed into 4 groups: sedentary control (SC), sedentary treated with Dexa (SD; 0,5 mg/kg per day, i.p., 10 days), trained control (TC) and trained treated with Dexa (TD) and underwent a training period where they were either submitted to a running protocol (60% of physical capacity, 5 days/week for 8 weeks) or kept sedentary. After T period, animals underwent Dexa treatment concomitant with training. Western Blot was performed to identify myostatin and p70S6k protein expression in the tibialis anterior (TA) and soleus (SOL) muscle. Ten days of Dexa treatment increased fasting glucose (SD=+62%), however previous T attenuated this increase (TD=+20%, p<0.05). Dexa determined significant decrease in body weight in TD (-22%) and SD (-25%), followed by TA weight reduction in SD (-23%) and TD (-20%). Previous training could not avoid these decreases. Myostatin protein expression was not altered by dexa treatment or training in TA muscle but in SOL muscle it was significantly modified after T, regardless of treatment (TC=+%23 and TD=+25) compared with their respective controls. The protein p70S6K was not modified neither by dexa nor training in any of the analyzed muscle or condition. The results of this study allowed us to conclude that previous training attenuates the hyperglycemia induced by Dexa, however it did not prevent the body or muscle weight reductions. Even in the presence of muscle atrophy, the expression of myostatin and p70S6K do not justify the mechanisms of muscle loss induced by Dexa, which suggests that other catabolic or anabolic proteins could be involved in the process of muscle atrophy after 10 days of treatment with Dexa