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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
431

Efeito da administração de gonadotrofina coriônica humana (hCG) no dia 4 após a IATF sobre tamanho, função luteal e taxa de prenhez em vacas de corte em lactação / Effect of administration of human chorionic gonadotrophin (hCG) on day 4 after f-tai on size, and luteal function and pregnancy rate in lactating beef cows

Thedy, Diego Xavier January 2014 (has links)
O objetivo deste estudo foi determinar os efeitos da aplicação de hCG no quarto dia após a inseminação a tempo fixo (IATF) sobre o tamanho do corpo lúteo (CL) existente, a indução de CL acessórios, a concentração de progesterona (P4) sérica e taxa de prenhez de vacas de corte em lactação. Nos três experimentos, vacas de corte multíparas (n=569), cruza Bos taurus, com período pós-parto entre 45 e 70 dias, foram sincronizadas com a administração de 2mg de benzoato de estradiol i.m. e a inserção de um dispositivo intravaginal contendo 0,750g de P4 (Dia -9). Sete dias após, administraram-se 150 μg de D-cloprostenol e 0,5 mg de cipionato de estradiol, i.m., no momento da retirada do dispositivo (Dia -2). Sessenta vacas de corte em lactação foram divididas aleatoriamente em dois grupos: hCG (n=30) tratadas com 1500UI i.m. de hCG e Controle (n=30) injetadas com 1,5 mL de solução salina i.m. no dia 4 depois do estro (Dia 0). Realizaram-se coletas sanguíneas dos animais para mensuração da concentração sérica de P4 nos Dias 4, 7, 10 e 14 do ciclo estral. Para acompanhamento da dinâmica ovariana, sessenta animais foram divididos aleatoriamente nos grupos hCG (n=30) ou Controle (n=30) e receberam o mesmo protocolo hormonal como citado anteriormente. No Dia 0, os ovários foram examinados por ultrassonografia transretal para determinar o diâmetro do folículo ovulatório; no Dia 4, o diâmetro do FD e presença do CL e no Dia 7 para mensurar a área luteal do CL e a presença de CL acessório. Quinhentas e sessenta e nove vacas (hCG, n= 269 e Controle, n= 300) foram inseminadas a tempo fixo 52-56 horas depois da retirada dos implantes de P4 e tratadas no Dia 4, conforme o protocolo descrito. O diagnóstico de prenhez foi realizado por ultrassonografia 30 dias após a IATF. Os resultados observados, mostraram que vacas tratadas com hCG no Dia 4 apresentaram maiores concentrações sérica de P4 no Dia 7, comparadas com as do grupo Controle (4,45 vs. 3,37ng/mL, respectivamente; p<0,05), mas níveis semelhantes de P4 nos Dias 10 e 14. Os animais do grupo hCG apresentaram CL com maior (p<0,01) área luteal no Dia 7, em relação ao grupo Controle (3,52 cm² vs. 2,66 cm², respectivamente) e uma incidência de 29,6 % de indução da ovulação do FD presente no Dia 4. Observou-se uma taxa de prenhez maior (p=0,071) no grupo tratado com hCG (53,9%) comparando-se com as vacas não tratadas (46,3%). Conclui-se que a administração de hCG no quarto dia do ciclo estral promove o aumento da área do CL, melhora função luteal, pode induzir a formação de CL acessório e tende a aumentar a taxa de prenhez de vacas de corte em lactação. / The aim of this study was to determine the effects of injection of hCG on the fourth day after the TAI on the size of the existing corpus luteum (CL), the induction of CL accessories, the concentration of progesterone (P4) levels and the possibility of increasing the rate of pregnancy of lactating beef cows subjected to synchronization of estrus and ovulation. Multiparous beef cows (n= 569), Bos taurus crossbreed with postpartum between 45 and 70 days were synchronized by administration of 2mg of estradiol benzoate im and the insertion of an intravaginal device containing 0,750g of P4 (Day -9). Seven days later, were administered 150mg of D- cloprostenol 0.5 mg of estradiol cypionate, im, at the time of device removal (Day -2). Sixty lactating beef cows were randomly divided into two groups: hCG (n= 30) treated with im 1500UI hCG and Control (n= 30) injected with 1.5 ml of saline im on day 4 after estrus (Day 0). There were blood collections of animals for measurement by radioimmunoassay of serum P4 on Days 4, 7, 10 and 14 of the estrous cycle. To evaluate the ovarian dinamics, sixty animals (hCG, n= 30 and Control, n = 30) received the same hormonal protocol and were uniformly distributed into groups according to the diameter of the ovulatory follicles on day 0 (estrus). On Day 0, the ovaries were examined by transrectal ultrasonography to determine the diameter of the ovulatory follicle, on Day 4, the diameter of the dominant follicle (DF) and the presence of CL on Day 7 to measure the area of the luteal CL and the presence of accessory CL. Five hundred and sixty-nine cows (hCG, n= 269 and Control, n= 300) were inseminated at a fixed time 52 to 56 hours after removal of the P4 devices treated on Day 4, according to the protocol described previously. The diagnosis of pregnancy were performed by ultrasonography 30 days after TAI. The results demonstrate that cows treated with hCG on Day 4 showed higher serum concentrations of P4 on Day 7, compared with the control group (4.45 vs. 3.37ng/mL, respectively, (p<0.05), but similar levels of P4 on Days 10 and 14. The animals of hCG group had greater (p<0,01) luteal area on Day 7, compared to the Control group (3.52cm² vs. 2.66cm², respectively) and a 29.6% incidence of induction DF ovulation present on Day 4. We observed a higher rate of pregnancy (p= 0.071) in the group treated with hCG (53.9%) comparing with untreated cows (46.3%). We conclude that administration of hCG on the fourth day of the estrous cycle increase the CL area, improves luteal function, can induce the formation of accessory CL and tends to increase the pregnancy rate of lactating beef cows.
432

Caracterização do pico de LH após protocolo de curta e longa duração para IATF em ovelhas ciclando na contra estação reprodutiva / Characterization of the LH peak after short and long-term protocol for FTAI in cycling sheep out of the breeding season

Soriano, Gabriela Azenha Milani 27 February 2015 (has links)
Made available in DSpace on 2016-01-26T18:55:42Z (GMT). No. of bitstreams: 1 GABRIELA SORIANO.pdf: 327520 bytes, checksum: ad8287a2a1dbd4d04e67e925087f4285 (MD5) Previous issue date: 2015-02-27 / The hypothesis tested in this study was that the time of permanence of progesterone implant (short vs. long) in FTAI protocol change the characteristics of the LH surge. Thus, the aim of this study was to determine the timing, duration and amplitude of the LH peak in sheep (Santa Inês x Texel) using short FTAI protocols (6 days) or long (12 days) in cyclic sheep out of the breeding season. We used 43 sheep (Texel-Te x Santa Inês-SI), sorted into two groups according to the time of progesterone release s vaginal device 1st use (Easy-Breed CIDR®, Pfizer, Brazil). In group 12 days (G-12, n = 19) in stage random of the estrous cycle received the insertion of CIDR (D0). On the day of implant removal (D12) was administered intramuscularly, 0.075 mg cloprostenol (Veteglan®, Hertape Calier, Brazil) and 300 IU equine chorionic gonadotropin (eCG, Novormon®, MSD Animal Health, Brazil). The group 6 (G-6, n= 24) received the same protocol of G-12, however the permanence of CIDR was 6 days. Approximately 50 hours after CIDR removal, both groups were inseminated at fixed time by artificial insemination by laparoscopy with frozen semen containing 200x106 sperm of a single player of Dorper. Approximately 40 days after the artificial insemination pregnancy diagnosis was performed using ultrasound device. Blood samples were taken every 4 hours from 10 animals per group, to measure LH and progesterone plasma concentrations by radioimmunoassay (RIA). From the 20 animals used for progesterone plasma concentration, the percentage of animals showing LH surge in G-6 was 70% (7/10) and the G-12 was 90% (9/10). The maximum amplitude of the LH peak did not differ between the G-6 and G-12 groups (P> 0.05) and the lengh of LH peak was 16,60±2,76 h in the G-6 and 16,40±2,40 h in G-12 (P>0,05). The interval between the implant removal and the LH surge was (P >0.05) in the G-6 27,42±2,76 h and 28,88±5,20 h in G-12. The overall pregnancy rate per group was not different (G-6 58,33% e G-12 52,63%). It was concluded that the permanence of progesterone (6 vs 12 days) did not alter the characteristics of the LH peak in sheep (St. Agnes x Texel) in the tropics, out of the breeding season. / A hipótese testada pelo presente trabalho foi que o tempo de permanência do implante de progesterona (curto vs longo), em protocolo de IATF, altera as características do pico de LH. Desta forma, o objetivo do presente estudo foi determinar o momento, duração e amplitude do pico de LH em ovelhas (Texel x Santa Inês) utilizando protocolos de IATF de curta (6 dias) ou longa duração (12 dias) em ovelhas ciclando na contra estação reprodutiva. Foram utilizadas 43 ovelhas (Texel-Te x Santa Inês-SI), divididas em dois grupos de acordo com o tempo de permanência do dispositivo vaginal de liberação de progesterona de 1° uso (Easy-Breed CIDR®, Pfizer, Brasil). No grupo 12 dias (G-12, n=19), em estádio aleatório do ciclo estral receberam a inserção do CIDR (D0). No dia da retirada do implante (D12) foram administrados, por via intramuscular, 0,075 mg de cloprostenol (Veteglan®, Hertape Calier, Brasil) e 300 UI de gonadotrofina coriônica equina (eCG, Novormon®, MSD Saúde Animal, Brasil). O grupo 6 (G-6, n=24) recebeu o mesmo protocolo do G-12, porém a permanência do CIDR foi de 6 dias. Aproximadamente 50 horas após a retirada do CIDR as ovelhas, de ambos os grupos, foram inseminadas em tempo fixo por laparoscopia com sêmen congelado contendo 200x106 espermatozóides, de um único reprodutor, da raça Dorper. Aproximadamente 40 dias após as inseminações artificiais foi realizado o diagnóstico de prenhez utilizando aparelho de ultra-som. Foram realizadas colheitas de sangue, de 4 em 4 horas em 10 animais por grupo, para mensuração das concentrações plasmáticas de LH e progesterona por radioimunoensaio (RIA). Dos 20 animais utilizados para mensuração das concentrações plasmáticas, a porcentagem de animais que apresentaram pico de LH no G-6 foi de 70% (7/10) e no G-12 foi 90% (9/10). A amplitude máxima do pico de LH não diferiu entre os grupos G-6 e G-12 (P>0,05) e a duração do pico de LH foi 16,60±2,76 h no grupo G-6 e 16,40±2,40 h no grupo G-12 (P>0,05). O intervalo entre a retirada do implante e o pico de LH foi (P>0,05) ocorreu 27,42±2,76 h no grupo G-6 e 28,88±5,20 h no G-12. A percentagem de prenhez total por grupo não diferiu (G-6 58,33% e G-12 52,63%). Conclui-se que o tempo de permanência da progesterona (6 vs 12 dias) não alterou as características do pico de LH em ovelhas (Texel x Santa Inês) nos trópicos, na contra estação reprodutiva.
433

Caracterização do pico de LH após protocolo de curta e longa duração para IATF em ovelhas ciclando na contra estação reprodutiva / Characterization of the LH peak after short and long-term protocol for FTAI in cycling sheep out of the breeding season

Soriano, Gabriela Azenha Milani 27 February 2015 (has links)
Made available in DSpace on 2016-07-18T17:53:14Z (GMT). No. of bitstreams: 1 GABRIELA SORIANO.pdf: 327520 bytes, checksum: ad8287a2a1dbd4d04e67e925087f4285 (MD5) Previous issue date: 2015-02-27 / The hypothesis tested in this study was that the time of permanence of progesterone implant (short vs. long) in FTAI protocol change the characteristics of the LH surge. Thus, the aim of this study was to determine the timing, duration and amplitude of the LH peak in sheep (Santa Inês x Texel) using short FTAI protocols (6 days) or long (12 days) in cyclic sheep out of the breeding season. We used 43 sheep (Texel-Te x Santa Inês-SI), sorted into two groups according to the time of progesterone release s vaginal device 1st use (Easy-Breed CIDR®, Pfizer, Brazil). In group 12 days (G-12, n = 19) in stage random of the estrous cycle received the insertion of CIDR (D0). On the day of implant removal (D12) was administered intramuscularly, 0.075 mg cloprostenol (Veteglan®, Hertape Calier, Brazil) and 300 IU equine chorionic gonadotropin (eCG, Novormon®, MSD Animal Health, Brazil). The group 6 (G-6, n= 24) received the same protocol of G-12, however the permanence of CIDR was 6 days. Approximately 50 hours after CIDR removal, both groups were inseminated at fixed time by artificial insemination by laparoscopy with frozen semen containing 200x106 sperm of a single player of Dorper. Approximately 40 days after the artificial insemination pregnancy diagnosis was performed using ultrasound device. Blood samples were taken every 4 hours from 10 animals per group, to measure LH and progesterone plasma concentrations by radioimmunoassay (RIA). From the 20 animals used for progesterone plasma concentration, the percentage of animals showing LH surge in G-6 was 70% (7/10) and the G-12 was 90% (9/10). The maximum amplitude of the LH peak did not differ between the G-6 and G-12 groups (P> 0.05) and the lengh of LH peak was 16,60±2,76 h in the G-6 and 16,40±2,40 h in G-12 (P>0,05). The interval between the implant removal and the LH surge was (P >0.05) in the G-6 27,42±2,76 h and 28,88±5,20 h in G-12. The overall pregnancy rate per group was not different (G-6 58,33% e G-12 52,63%). It was concluded that the permanence of progesterone (6 vs 12 days) did not alter the characteristics of the LH peak in sheep (St. Agnes x Texel) in the tropics, out of the breeding season. / A hipótese testada pelo presente trabalho foi que o tempo de permanência do implante de progesterona (curto vs longo), em protocolo de IATF, altera as características do pico de LH. Desta forma, o objetivo do presente estudo foi determinar o momento, duração e amplitude do pico de LH em ovelhas (Texel x Santa Inês) utilizando protocolos de IATF de curta (6 dias) ou longa duração (12 dias) em ovelhas ciclando na contra estação reprodutiva. Foram utilizadas 43 ovelhas (Texel-Te x Santa Inês-SI), divididas em dois grupos de acordo com o tempo de permanência do dispositivo vaginal de liberação de progesterona de 1° uso (Easy-Breed CIDR®, Pfizer, Brasil). No grupo 12 dias (G-12, n=19), em estádio aleatório do ciclo estral receberam a inserção do CIDR (D0). No dia da retirada do implante (D12) foram administrados, por via intramuscular, 0,075 mg de cloprostenol (Veteglan®, Hertape Calier, Brasil) e 300 UI de gonadotrofina coriônica equina (eCG, Novormon®, MSD Saúde Animal, Brasil). O grupo 6 (G-6, n=24) recebeu o mesmo protocolo do G-12, porém a permanência do CIDR foi de 6 dias. Aproximadamente 50 horas após a retirada do CIDR as ovelhas, de ambos os grupos, foram inseminadas em tempo fixo por laparoscopia com sêmen congelado contendo 200x106 espermatozóides, de um único reprodutor, da raça Dorper. Aproximadamente 40 dias após as inseminações artificiais foi realizado o diagnóstico de prenhez utilizando aparelho de ultra-som. Foram realizadas colheitas de sangue, de 4 em 4 horas em 10 animais por grupo, para mensuração das concentrações plasmáticas de LH e progesterona por radioimunoensaio (RIA). Dos 20 animais utilizados para mensuração das concentrações plasmáticas, a porcentagem de animais que apresentaram pico de LH no G-6 foi de 70% (7/10) e no G-12 foi 90% (9/10). A amplitude máxima do pico de LH não diferiu entre os grupos G-6 e G-12 (P>0,05) e a duração do pico de LH foi 16,60±2,76 h no grupo G-6 e 16,40±2,40 h no grupo G-12 (P>0,05). O intervalo entre a retirada do implante e o pico de LH foi (P>0,05) ocorreu 27,42±2,76 h no grupo G-6 e 28,88±5,20 h no G-12. A percentagem de prenhez total por grupo não diferiu (G-6 58,33% e G-12 52,63%). Conclui-se que o tempo de permanência da progesterona (6 vs 12 dias) não alterou as características do pico de LH em ovelhas (Texel x Santa Inês) nos trópicos, na contra estação reprodutiva.
434

EFEITO DA SUPLEMENTAÇÃO COM SEMENTE DE GIRASSOL SOBRE A MORFOMETRIA E ENDOCRINOLOGIA LUTEÍNICAS DE NOVILHAS DA RAÇA NELORE / EFFECT OF SUPPLEMENTATION WITH SUNFLOWER SEED ON THE MORPHOMETRY AND LUTEIN ENDOCRINOLOGY HEIFERS OF NELORE

MATTOS, Gabriel Molinari de 25 March 2016 (has links)
Submitted by Adriana Martinez (amartinez@unoeste.br) on 2016-08-15T17:53:17Z No. of bitstreams: 1 Gabriel Molinari de Mattos.pdf: 259716 bytes, checksum: 4ece0001439fe6d5a4573f9a3129ac49 (MD5) / Made available in DSpace on 2016-08-15T17:53:17Z (GMT). No. of bitstreams: 1 Gabriel Molinari de Mattos.pdf: 259716 bytes, checksum: 4ece0001439fe6d5a4573f9a3129ac49 (MD5) Previous issue date: 2016-03-25 / This study aimed to evaluate the luteal development and the plasma concentration of progesterone in pregnant Nelore heifers and non-pregnant supplemented with sunflower seed. 30 animals were aged 2 to 3 years, with body condition score 2.5 to 3.5 (1 to 5), kept in Brachiaria decumbens, water and mineral salt ad libitum. Before starting the sonographic evaluations of the reproductive system, heifers were divided into two groups where they received: 1.7 kg / day of dietary supplement with 40% soybean meal and 60% sunflower seed (Group Treaty GT: n = 11) or 1.7 kg / day of dietary supplement containing 53% of soybean meal, 47% corn (control group, CG, n = 15) for 60 days. Immediately after this period heifers were synchronized ovulation with hormonal protocol TAI (artificial insemination in fixed time) lasting eight days. On AI held ultrasound examination (US) of the ovaries and blood collection to monitor the development of the corpus luteum (CL) and plasma progesterone (P4), every 48 hours for 26 days. CL diameter was observed on days 22, 24 and 26 after IA in pregnant females, where the diameter was significantly greater (P <0.05) than in non-pregnant, regardless of diet. There was no treatment effect on plasma progesterone concentrations, but the reproductive status influenced (P <0.05). There was a higher concentration of P4 in pregnant animals from day 16 after AI. It is concluded that the diet with sunflower seed did not influence the concentration of progesterone and diameter of the corpus luteum. It was observed that the reproductive status influenced the diameter P4 and CL. / Objetivou-se avaliar o desenvolvimento luteal e a concentração plasmática de progesterona em novilhas da raça Nelore prenhes e não prenhes suplementadas com semente de girassol. Foram utilizados 30 animais com idade de 2 a 3 anos, com escore de condição corporal de 2,5 a 3,5 (1 a 5), mantidas em pastagem de Brachiaria decumbens, com água e sal mineral ad libitum. Antes de iniciar as avaliações ultrassonográficas do aparelho reprodutor, as novilhas foram divididas em dois grupos, onde receberam: 1,7 Kg/dia de suplemento alimentar com 40% de farelo de soja e 60% de semente de girassol (Grupo Tratado, G-T: n=11) ou 1,7Kg/dia de suplemento alimentar contendo 53% de farelo de soja e 47% de milho (Grupo Controle, G-C: n=15) durante 60 dias. Imediatamente após este período as novilhas tiveram a ovulação sincronizada com protocolo hormonal de IATF (inseminação artificial em tempo fixo) com duração de 8 dias. No dia da IA realizou-se exame de ultrassom (US) dos ovários e coleta de sangue para acompanhar o desenvolvimento do corpo lúteo (CL) e concentração plasmática de progesterona (P4), a cada 48 horas, durante 26 dias. Foi observado diâmetro do CL nos dias 22, 24 e 26 após IA, nas fêmeas prenhes, onde o diâmetro foi significativamente maior (P<0,05) que nas não prenhes, independente da dieta. Não houve efeito do tratamento nas concentrações plasmáticas de progesterona, mas o status reprodutivo influenciou (P<0,05). Foi observada maior concentração de P4 nos animais gestantes a partir do dia 16 após IA. Conclui-se que a dieta com semente de girassol não influenciou a concentração de progesterona e diâmetro do corpo lúteo. Observou-se que o status reprodutivo influenciou a concentração de P4 e diâmetro do CL.
435

Characterization of miR-888 expression and regulation in endometrial cancer

Hovey, Adriann Marie 01 May 2014 (has links)
Endometrial cancer is the fourth most common cancer in women and the most common gynecological malignancy. While patient outcome has improved for the majority of cancers, the outlook for endometrial cancer has steadily decreased. In order to address this problem, we must better understand the different mechanisms involved in endometrial cancer development and progression. To this end, we quantified expression of 667 miRNAs in four endometrioid adenocarcinoma and four serous adenocarcinoma using Taqman Low Density Arrays (TLDAs). miR-888 was one of the most highly overexpressed miRNAs in both endometrial cancer subtypes. Analysis of miR-888 expression across multiple cancer types using the The Cancer Genome Atlas database revealed that miR-888 was selectively expressed in endometrial cancer, with a significant association to invasive and high grade tumors. In addition, miR-888 was most predominantly expressed in endometrial carcinosarcoma, a rare but deadly form of endometrial cancer. Therefore, we conclude that miR-888 expression marks an aggressive endometrial tumor phenotype. One of the top predicted targets of miR-888 by TargetScan is the progesterone receptor (PR). PR is a potent tumor suppressor of the endometrium whose expression is often lost in advanced endometrial cancers. We quantified PR mRNA expression in a panel of endometrial tumors and found a statistically significant, negative correlation between miR-888 and PR mRNA expression. Furthermore, overexpression of miR-888 in endometrial cancer cell lines was capable of decreasing PR at the protein level. To determine if miR-888 directly targets PR, we cloned each of the four miR-888 binding sites downstream of Renilla luciferase into the psiCHECK2 reporter vector. miR-888 overexpression was capable of decreasing luciferase activity for all four binding sites, with the second and third binding sites producing the most prominent results. Here we describe a novel mechanism by which miR-888 inhibits PR mRNA translation to negatively regulate PR expression in endometrial tumors. To determine the endogenous function of miR-888 in human cells, we quantified miR-888 in a panel of 21 normal human tissues. Interestingly, miR-888 was highly expressed in testes, with minimal or absence of expression in all other tissues investigated. The restricted expression pattern of miR-888 in testes and cancer suggested that miR-888 may qualify as a novel cancer-testis (CT) antigen. CT-antigens are a large class of genes that demonstrate selective expression normally in testes germ cells and abnormally in various types of cancer. Furthermore, CT-antigen genes are predominantly located on the X chromosome and are part of evolutionarily novel multicopy gene families. Indeed, miR-888 is part of a multicopy, primate-specific miRNA gene family located on the X-chromosome. Furthermore, miRNA in situ hybridization localized miR-888 expression to the early stages of spermatogenesis, as is often observed for CT antigens. Together, these data identify miR-888 as the first miRNA CT antigen and expand the CT antigen field to noncoding RNAs.
436

Der Einfluss von Glukokortikoiden und Progesteron auf den epithelialen Natriumtransport: Der Einfluss von Glukokortikoiden und Progesteron auf den epithelialenNatriumtransport

Hornbostel, Carolin 15 June 2016 (has links)
Der epitheliale Natriumtransport in der postnatalen Lunge ist für einen ausgeglichenen Flüssigkeitstransport und eine gesunde Lungenfunktion unabdingbar. Eine bedeutende Rolle spielt hierbei der epitheliale Natriumkanal (ENaC). Es ist bereits bekannt, dass unter dem Einfluss von weiblichen Sexualhormonen, wie Progesteron, oder durch die Substitution von Glukokortikoiden, wie Dexamethason, die mRNA-Expression des ENaC und dessen elektrophysiologische Aktivität erhöht wird. Zur Lungenreifeinduktion werden bei Frühgeburtlichkeitsbestrebungen hohe Dosen von Glukokortikoiden verabreicht, die im fetalen Kreislauf auf hohe Progesteronkonzentrationen treffen. Die Auswirkung dieser Hormonkombination auf den epithelialen Natriumtransport ist bisher unbekannt. Um dieser Frage nachzugehen, wurden alveoläre Epithelzellen von Rattenfeten auf permeablen Membranen gezüchtet und mit unterschiedlichen Konzentrationen von Progesteron und Dexamethason inkubiert. Anschließend wurde die mRNA-Expression der drei Untereinheiten des ENaC (α, β, γ) mittels Real-Time PCR analysiert. Mit Hilfe von Ussing-Kammer Messungen wurden die Einflüsse auf den epithelialen Natriumtransport ermittelt. Durch die Experimente konnte der stimulierende Einfluss beider Hormone auf die mRNA-Expression bestätigt werden, wobei Dexamethason einen deutlich stärkeren Effekt erreichte. Durch die Kombination beider Hormone kam es zu einer signifikant geringeren mRNA-Expression und einem verminderten funktionellen Natriumtransport im Vergleich zur reinen Dexamethasoninkubation. Der Einsatz von Hormonrezeptor-Antagonisten zeigte, dass eine Blockierung des Progesteronrezeptors die mRNA-Expression erhöhte, wohingegen die Hemmung des Glukokortikoidrezeptors die mRNA-Expression der ENaCUntereinheiten verminderte. Zusammenfassend zeigen die Ergebnisse, dass Glukokortikoide und weibliche Geschlechtshormone, die einzeln zur Erhöhung der Natriumabsorption führen, durch die Kombination beider Hormone ihren Einfluss auf den Natriumtransport reduzieren.
437

Progesterone Facilitates the Acquisition of Avoidance Learning and Protects Against Subcortical Neuronal Death Following Prefrontal Cortex Ablation in the Rat

Asbury, E. Trey, Fritts, Mary E., Horton, James E., Isaac, Walter L. 01 December 1998 (has links)
Following a cortical injury, neurons in areas near and connected to the site of injury begin to degenerate. The observed neuronal death may contribute to the severity of the observed behavioral impairments. The purpose of the present study was to examine if progesterone, a hormone known for its effectiveness at reducing cerebral edema, could protect against secondary neuronal death and facilitate the acquisition of an avoidance learning task in an ablation model of cortical injury. Rats served as sham controls or received bilateral ablation of the medial prefrontal cortex followed by a 10-day regimen of progesterone (4 mg/kg) or oil vehicle (1 ml/kg) beginning 1 h after cortical lesions. Progesterone-treated lesion rats showed a significant facilitation of avoidance learning compared to oil- treated lesion controls. In addition, progesterone-treated lesion animals did not differ from either progesterone- or oil-treated sham controls in avoidance learning. Anatomical analysis revealed that progesterone treatment decreased the amount of neuronal death seen in the striatum and the mediodorsal nucleus of the thalamus. The findings are consistent with the notion that progesterone is an effective neuroprotective agent and suggest that the hormone can reduce the behavioral impairments associated with frontal cortical ablation injury.
438

Liquid Chromatography–Mass Spectrometry Applications for Quantification of Endogenous Sex Hormones

Gravitte, Amy, Archibald, Timothy, Cobble, Allison, Kennard, Benjamin, Brown, Stacy D. 01 January 2021 (has links)
Liquid chromatography, coupled with tandem mass spectrometry, presents a powerful tool for the quantification of the sex steroid hormones 17-β estradiol, progesterone and testosterone from biological matrices. The importance of accurate quantification with these hormones, even at endogenous levels, has evolved with our understanding of the role these regulators play in human development, fertility and disease risk and manifestation. Routine monitoring of these analytes can be accomplished by immunoassay techniques, which face limitations on specificity and sensitivity, or using gas chromatography–mass spectrometry. LC–MS/MS is growing in capability and acceptance for clinically relevant quantification of sex steroid hormones in biological matrices and is able to overcome many of the limitations of immunoassays. Analyte specificity has improved through the use of novel derivatizing agents, and sensitivity has been refined through the use of high-resolution chromatography and mass spectrometric technology. This review highlights these innovations, among others, in LC–MS/MS steroid hormone analysis captured in the literature over the last decade.
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The Complexity of Interactions Between Female Sex Hormones and Chlamydia Trachomatis Infections

Berry, Amy, Hall, Jennifer V. 15 June 2019 (has links)
Recent Findings: Recent data support previous work indicating that estrogen enhances chlamydial development via multiple mechanisms. Progesterone negatively impacts Chlamydia infections also through multiple mechanisms, particularly by altering the immune response. Conflicting data exist regarding the effect of synthetic hormones, such as those found in hormonal contraceptives, on chlamydial infections. Summary: Numerous studies over the years have indicated that female sex hormones affect C. trachomatis infection. However, we still do not have a clear understanding of how these hormones alter Chlamydia disease transmission and progression. The studies reviewed here indicate that there are many variables that determine the outcome of Chlamydia/hormone interactions, including (1) the specific hormone, (2) hormone concentration, (3) cell type or area of the genital tract, (4) hormone responsiveness of cell lines, and (5) animal models.
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Regulation of Prostaglandin Biosynthesis by Estrogen and Progesterone in Simian and Ovine Endometrium: a Thesis

Eldering, Joyce A. 01 March 1990 (has links)
Endometrial prostaglandins (PGs) play a role in menstruation in primates and in luteolysis in nonprimates. Their biosynthesis is regulated by estrogen (E) and progesterone (P) in a manner not fully understood. The purpose of this thesis research was to (1) study the effects of E and P, both in vivo and in vitro, on basal endometrial PG output in vitro during the course of the artificial menstrual cycle in the rhesus monkey, and (2) further to examine the cellular mechanisms of P action in vivo on PG output using an ovine model system. To carry out the first objective, ovariectomized rhesus monkeys (n=39) were maintained on either a standard or manipulated artificial menstrual cycle (SAMC and MAMC, respectively) and endometrial biopsies were obtained at precise times in separate cycles on: cycle day 9 (mid-proliferative), 13 (mid-cycle E peak), 14 (one day post E peak), and 23 (mid-secretory). PGF2α was the most abundant PG produced in vitro by endometrial organ cultures, the levels of which changed most dramatically throughout the SAMC. Within the first 24 hours of organ culture, PGF2α accumulation was low on day 9 and rose significantly (p<0.01) on day 13, indicating a stimulatory effect of E in vivo. However, E added in vitro, at either physiologic or supraphysiologic concentrations, to endometrial cultures did not stimulate PGF2α accumulation on any cycle day examined. On day 14, just one day post E peak, there was a dramatic fall in PGF2α accumulation which appeared to be due to both a decline in stimulatory E in vivo and a rise in inhibitory P in vivo. Basal PGF2α accumulation in vitro by day 23 endometrial cultures was 10-fold higher (p<0.01) compared to days 9 and 14. This high level of PGF2α output on day 23 appeared to be caused by a paradoxical priming effect of P in vivo and also a slight enhancement by the mid-cycle peak of E in vivo. Padded in vitro, at a physiologic concentration, to day 23 endometrial cultures markedly inhibited (p<0.01) the high level of PGF2α accumulation, suggesting that P withdrawal in vivo promotes the rise in endometrial PGF2α production in vivo at the time of menstruation in primates. An ovine model system was further used to investigate the cellular mechanisms of P action in vivo. Ovariectomized sheep (n=8) were administered an infusion regimen of either E and P, or E and P vehicle alone, to examine the effects of P in vivo on PGF2α production in vitro by endometrial explants during short-term incubations. P in vivo increased the mass amount of stimulated PGF2α output by both physiologic and pharmacologic mechanisms. In addition, P did not appear to significantly alter the sensitivity of the endometrium to stimulatory levels of oxytocin in vitro indicating that the cellular events accounting for the P priming effect, in part, may occur independent of the oxytocin receptor closer to the PG biosynthetic pathway. In P-primed endometrium, the mass amount of PGF2α stimulated by a calcium-ionophore (A23l87) was less than that stimulated by OT suggesting the involvement of calcium-insensitive mechanisms in PGF2α synthesis.

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