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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.
21

Terminação de cordeiros com cana-de-açúcar in natura ou hidrolisada com óxido de cálcio em ambientes aeróbico e anaeróbico

Endo, Viviane [UNESP] 01 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-01Bitstream added on 2014-06-13T18:34:26Z : No. of bitstreams: 1 endo_v_me_jabo.pdf: 582582 bytes, checksum: 3464bf8d019728c103eb70fb996f52cc (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Foram utilizados 24 cordeiros Ile de France confinados dos 15 kg aos 32 kg de peso corporal em baias individuais com controle diário do alimento fornecido e das sobras. Os tratamentos, IN: cana-de-açúcar in natura + concentrado, AER: cana-de-açúcar hidrolisada com 0,6% de óxido de cálcio (CaO) em ambiente aeróbico + concentrado e ANA: cana-de-açúcar hidrolisada com 0,6% de CaO em ambiente anaeróbico + concentrado em um delineamento inteiramente casualizado, com oito repetições cada tratamento. Cordeiros alimentados com cana-de-açúcar hidrolisada em ambiente anaeróbico apresentaram maior balanço de nitrogênio (29,46 g/dia e 2,80 g/kg0,75/dia), teor de nitrogênio absorvido (2,98 g/kg0,75/dia), teor de vermelho (a*) aos 45 minutos (10,48) e extrato etéreo (2,77%) no músculo Longissimus lumborum. O maior coeficiente de digestibilidade da fibra em detergente neutro corrigido para cinzas e proteína foi observado para cordeiros alimentados com cana-de-açúcar hidrolisada (aeróbico, 51,70% ou anaeróbico, 53,75%). O maior comprimento da perna in vivo (32,21 cm), menor altura do posterior (55,23 cm) e perdas na dissecação do lombo (1,83%) foram encontrados para cordeiros terminados com cana-de-açúcar hidrolisada em ambiente aeróbico. Menor teor de gordura intermuscular (4,77%) e peso corporal vazio (24,84 kg) foram observados para cordeiros alimentados com cana-de-açúcar in natura. O fornecimento da cana-de-açúcar na forma in natura se torna viável por dispensar o processo de preparo da solução da calda e do revolvimento para homogeneização dos amontoados de cana-de-açúcar, além de não haver necessidade da compra do agente alcalinizante / It were used 24 lambs Ile de France, non-castrated, fed with diets containing in nature or hydrolyzed sugar cane in aerobic and anaerobic environments on a roughage: concentrate ratio, 50:50. The lambs were confined to 15 kg body weight, which received the diet in individual stalls in the trough, with control of food offered and the leftovers, and were slaughtered at 32 kg body weight. Lambs fed with hydrolyzed sugar cane in anaerobic environment had higher nitrogen balance (29.46 g / day and 2.80 g/kg0, 75/day), ratio of nitrogen absorbed (2.98 g/kg0, 75/day), level of value for red (a*) at 45 minutes (10.48) and ether extract (2.77%) of Longissimus lumborum muscle. The higher digestibility of neutral detergent fiber corrected for ash and protein was observed for lambs fed with hydrolyzed sugar cane independently of the environment of hydrolysis (aerobic, 51.70% or anaerobic, 53.75%). There was a greater length of leg in vivo (32.21 cm), smaller posterior (55.23 cm) and loss (1.83%) for lambs fed with hydrolyzed sugar cane in aerobic environment. Lower content of intermuscular fat (4.77%) and empty body weight (24.84 kg) for lambs fed sugar cane in nature. The hydrolyzed sugar cane provided better utilization of the fibers, but did not affect performance of animals in nature sugar cane in lambs feeding was shown to increase the quantitative traits in vivo of the lambs, but did not improve and/or damaged in carcass quantitative traits when compared with treatment with hydrolyzed sugar cane, so the use of hydrolyzed sugar cane is feasible to waive daily cuts, consequently, reduces workmanship. The supply of in nature sugar cane becomes feasible to waive the process of the preparation of the solution and revolving for homogenization of the piles of sugar cane and there is no need to purchase the alkalizing agent
22

Neuroendocrine control of appetite and reproduction in sheep

Archer, Zoe Anne January 2001 (has links)
Reproductive neuroendocrine activity and appetite are modulated at the hypothalamus by both nutritional status and photoperiod in the seasonal animal. The objectives of this work were (1) to measure circulating hormones and/or metabolites that relay information about peripheral nutritional status to the hypothalamus, (2) to identify which hypothalamic neuropeptides and receptors that are responsive to photoperiodic and nutritional feedback and (3) to establish which changes in peripheral signals and/or hypothalamic neuropeptides are associated with alterations in the activity of the reproductive neuroendocrine axis. Three main experiments were carried out. The first experiment (Chapter 1) utilised a 2 x 2 design to examine the separate and interactive effects of photoperiod and food restriction on hypothalamic neuropeptide and receptor mRNA expression and on GnRH/LH secretion. In the second experiment (Chapter 2), two components of nutritional status, BC and increased food intake were investigated since both are positively related to reproductive performance in sheep. In the final experiment (Chapter 3) the approach was to use an exogenous treatment to artificially raise plasma insulin in an attempt to "drive" some of the foregoing effects. Collectively these studies have lead to the first localisation AgRp, MCH, orexin, Mc3R, Mc4R gene expression in the ovine hypothalamus. They indicate that circulating insulin and leptin are major factors relaying information about nutritional status to the hypothalamus. In addition, they have dissociated BC and food intake as signals to the hypothalamus. Moreover these studies have provided no evidence that NPY, AgRp, POMC, MCH and ObRb play a role in driving seasonal changes in appetite and gonadotrophin secretion. However they do suggest NPY-ergic and melanocortin pathways are important in maintaining appetite/bodyweight/energy homeostasis or restoring energy balance following perturbation. Furthermore the results show that changes in nutrient-sensitive hypothalamic neuropeptide and receptor gene expression may not necessarily lead to alterations in the activity of the reproductive neuroendocrine axis. However, they do indicate that increased NPY biosynthesis during food restriction may be involved in the inhibition of pulsatile GnRH/LH release.
23

Avaliação clínica e estudo da ocorrência de fêmeas ovinas infectadas por micoplasmas na região de Piedade - SP - \"Avaliação da infecção sobre a produtividade do rebanho\" / Clinical avaliation and ocurrence studies of mycoplasmas infected ovine female in the Piedade region - State of São Paulo- \"Avaliation of the infection in the productivity of the herd\"

Rizzo, Huber 17 January 2006 (has links)
Com a crescente demanda por produtos ovinos, tem crescido o número de empresários dispostos a investir nessas atividades. Estudos sobre a importância das micoplasmoses e suas diferentes espécies já conhecidas ainda devem ser realizadas no Brasil. Foram estudadas 60 fêmeas da espécie ovina. O material clínico selecionado para analisar foi muco vulvovaginal obtido através de colheita por zaragatoa. Foi obtido o isolamento através de cultivo e a detecção pela técnica de reação em cadeia da polimerase de Mycoplasma spp., Ureaplasma spp. e Acholeplasma laidlawii em fêmeas de ovinos pela primeira vez no Brasil na região vulvovaginal. A porcentagem de micoplasma genérico detectada nas amostras foi de 75%, de Ureaplasma spp. foi de 66,7% e de Acholeplasma laidwaii foi de 1,7%. Houve isolamento em placa de 11,7% de Ureaplasma spp. do total de amostras processadas e de Micoplasma spp. em 8,3%. Não foi possível a identificação da espécie envolvida. Não houve associação da presença de micoplasmas com alterações no trato reprodutivo de fêmeas ovinas. Foi comprovada a infecção de uma fêmea ovina através de monta natural por um macho infectado, provando que uma das principais fontes de infecção dos animais é através do coito. / Sheep industry is growing rapidly in Brazil. However many diseases are the principal bottleneck to the increasing these activities. Among the reproductive diseases the vulvo-vaginites caused by Mycoplasma play an important role. Although no studies has been carried out in brazilian sheep herd so far. For that 60 ewes were ramdomly from different flocks selected at the county of Piedade state of São Paulo, Brazil. The mucus from vulvovagina was obtained by swab for isolation and detectetion of Mycoplasma spp., Ureaplasma spp. and Acholeplasma laidlawii. Generic Mycoplasma was detected in 75% of the samples, Ureaplasma spp. in 66,7% and Acholeplasma laidwaii in 1,7%. Mycoplasma spp. was isolated 8,3% and Ureaplasma spp. in 11,7%. It was not possible the identification of the species found. There was no association of mycoplasmas in the muco on the presence of reproductive problems in the herds. At least in one case, ram with presence of Mycoplasma in the semen infected a negative ewe, suggesting the importance of the ram in spreading the bacteria in the heard.
24

Recovery and evaluation of somatic cells from ovine and bovine semen for use in nuclear transfer

Liu, Jie 15 May 2009 (has links)
Somatic cells in semen are a potential source of nuclei for cloning animals bysomatic cell nuclear transfer. Culture of the cells from frozen semen, if possible, wouldbe extremely valuable for preservation or restoration of endangered, exotic, and extinctanimals when other ways of obtaining somatic cells are unavailable. In the present study,somatic cells isolated from ovine and bovine semen samples were characterized, culturesystems were evaluated for attachment and proliferation of these cells, and usefulness ofthese cells for somatic cell nuclear transfer was determined.Semen samples were collected from eight rams representing three breeds:Dorper, Suffolk, and Hampshire and nine bulls representing three breeds: Charolais,Brahman, and a crossbred Brahman. Somatic cells were isolated immediately postcollection by centrifuging through percoll columns and the epithelial cells wereidentified by immunofluorescence analysis. Culture systems were evaluated for theirability to support attachment and proliferation of the cells. A supplemented mediumcomposed of DMEM/F12, 10% fetal bovine serum, 10 ng/ml epidermal growth factor, 30 g/ml bovine pituitary extract, 5 g/ml insulin, 10 ng/ml cholera toxin, and 50 g/mlgentamicin significantly improved cell proliferation over sheep fetal fibroblastconditionedmedium, 3T3 cell-conditioned medium, and basic medium (p<0.05). Cellproliferation and attachment were further improved when Matrigel-coated culturesurfaces were used (p<0.05). However, the system was not adequate for obtaining cellgrowth from frozen semen.To check the chromosome anomalies, metaphase chromosomal complements ofthe cells cultured from 4 rams were evaluated. The predominant chromosome number ofcells from three of the rams (Dorper 18-month-old; Suffolk 17-month-old; Suffolk 18-month-old) was 2n = 54, which is the normal modal number for sheep. However, thenumbers of chromosomes of cells cultured from the fourth ram (Hampshire, 18-monthold)were near-triploid. These results indicate the need for chromosome analysis of cellsbefore using them for cloning experiments. In our attempts to clone animals, blastocyststage embryos were successfully produced using epithelial cells cultured from semen ofthree different bulls. However, no compact morulae or blastocysts were obtained whensomatic cells isolated from frozen semen but not cultured were used as donor cells.
25

Recovery and evaluation of somatic cells from ovine and bovine semen for use in nuclear transfer

Liu, Jie 15 May 2009 (has links)
Somatic cells in semen are a potential source of nuclei for cloning animals bysomatic cell nuclear transfer. Culture of the cells from frozen semen, if possible, wouldbe extremely valuable for preservation or restoration of endangered, exotic, and extinctanimals when other ways of obtaining somatic cells are unavailable. In the present study,somatic cells isolated from ovine and bovine semen samples were characterized, culturesystems were evaluated for attachment and proliferation of these cells, and usefulness ofthese cells for somatic cell nuclear transfer was determined.Semen samples were collected from eight rams representing three breeds:Dorper, Suffolk, and Hampshire and nine bulls representing three breeds: Charolais,Brahman, and a crossbred Brahman. Somatic cells were isolated immediately postcollection by centrifuging through percoll columns and the epithelial cells wereidentified by immunofluorescence analysis. Culture systems were evaluated for theirability to support attachment and proliferation of the cells. A supplemented mediumcomposed of DMEM/F12, 10% fetal bovine serum, 10 ng/ml epidermal growth factor, 30 g/ml bovine pituitary extract, 5 g/ml insulin, 10 ng/ml cholera toxin, and 50 g/mlgentamicin significantly improved cell proliferation over sheep fetal fibroblastconditionedmedium, 3T3 cell-conditioned medium, and basic medium (p<0.05). Cellproliferation and attachment were further improved when Matrigel-coated culturesurfaces were used (p<0.05). However, the system was not adequate for obtaining cellgrowth from frozen semen.To check the chromosome anomalies, metaphase chromosomal complements ofthe cells cultured from 4 rams were evaluated. The predominant chromosome number ofcells from three of the rams (Dorper 18-month-old; Suffolk 17-month-old; Suffolk 18-month-old) was 2n = 54, which is the normal modal number for sheep. However, thenumbers of chromosomes of cells cultured from the fourth ram (Hampshire, 18-monthold)were near-triploid. These results indicate the need for chromosome analysis of cellsbefore using them for cloning experiments. In our attempts to clone animals, blastocyststage embryos were successfully produced using epithelial cells cultured from semen ofthree different bulls. However, no compact morulae or blastocysts were obtained whensomatic cells isolated from frozen semen but not cultured were used as donor cells.
26

Avaliação clínica e estudo da ocorrência de fêmeas ovinas infectadas por micoplasmas na região de Piedade - SP - \"Avaliação da infecção sobre a produtividade do rebanho\" / Clinical avaliation and ocurrence studies of mycoplasmas infected ovine female in the Piedade region - State of São Paulo- \"Avaliation of the infection in the productivity of the herd\"

Huber Rizzo 17 January 2006 (has links)
Com a crescente demanda por produtos ovinos, tem crescido o número de empresários dispostos a investir nessas atividades. Estudos sobre a importância das micoplasmoses e suas diferentes espécies já conhecidas ainda devem ser realizadas no Brasil. Foram estudadas 60 fêmeas da espécie ovina. O material clínico selecionado para analisar foi muco vulvovaginal obtido através de colheita por zaragatoa. Foi obtido o isolamento através de cultivo e a detecção pela técnica de reação em cadeia da polimerase de Mycoplasma spp., Ureaplasma spp. e Acholeplasma laidlawii em fêmeas de ovinos pela primeira vez no Brasil na região vulvovaginal. A porcentagem de micoplasma genérico detectada nas amostras foi de 75%, de Ureaplasma spp. foi de 66,7% e de Acholeplasma laidwaii foi de 1,7%. Houve isolamento em placa de 11,7% de Ureaplasma spp. do total de amostras processadas e de Micoplasma spp. em 8,3%. Não foi possível a identificação da espécie envolvida. Não houve associação da presença de micoplasmas com alterações no trato reprodutivo de fêmeas ovinas. Foi comprovada a infecção de uma fêmea ovina através de monta natural por um macho infectado, provando que uma das principais fontes de infecção dos animais é através do coito. / Sheep industry is growing rapidly in Brazil. However many diseases are the principal bottleneck to the increasing these activities. Among the reproductive diseases the vulvo-vaginites caused by Mycoplasma play an important role. Although no studies has been carried out in brazilian sheep herd so far. For that 60 ewes were ramdomly from different flocks selected at the county of Piedade state of São Paulo, Brazil. The mucus from vulvovagina was obtained by swab for isolation and detectetion of Mycoplasma spp., Ureaplasma spp. and Acholeplasma laidlawii. Generic Mycoplasma was detected in 75% of the samples, Ureaplasma spp. in 66,7% and Acholeplasma laidwaii in 1,7%. Mycoplasma spp. was isolated 8,3% and Ureaplasma spp. in 11,7%. It was not possible the identification of the species found. There was no association of mycoplasmas in the muco on the presence of reproductive problems in the herds. At least in one case, ram with presence of Mycoplasma in the semen infected a negative ewe, suggesting the importance of the ram in spreading the bacteria in the heard.
27

Técnicas de ovariectomias por videolaparoscopia em ovelhas da raça Santa Inês /

Barros, Felipe Farias Pereira da Câmara. January 2012 (has links)
Orientador: Wilter Ricardo Russiano Vicente / Banca: José Antonio Marques / Banca: Carlos Eduardo Bezerra de Moura / Resumo: A castração de fêmeas se mostra importante na produção animal. Porém, existem poucas técnicas de ovariectomia descritas em pequenos ruminantes. Desta forma, objetiva-se com o presente estudo propor técnicas alternativas por videolaparoscopia e avaliá-las quanto ao desconforto doloroso dos animais e consequentemente queda na produção, viabilidade e tempo de execução. Sendo assim, primeiramente descreveu-se e comparou-se a ovariectomia por laparotomia (OL), vídeo-assistida (OVA) e total vídeolaparoscópica (OTV) em ovelhas da raça Santa Inês adultas, avaliando o trans e pós-cirúrgico, e verificando o estresse causado às fêmeas por cada procedimento. Já em um segundo momento objetivou-se desenvolver e descrever uma técnica de ovariectomia por videolaparoscopia utilizando um portal laparoscópico e um sistema de ligadura pré-montada (OTVM), avaliando a sua viabilidade, o desconforto doloroso e o processo inflamatório provocado em ovelhas da mesma raça. Concluiu-se então que as técnicas OVA e OTV apresentaram grande vantagem em relação a OL por serem processos minimamente invasivos, de rápida realização e que proporcionam mínimo desconforto e ótima recuperação das ovelhas, sendo recomendado por causar mínimo estresse e decréscimo na produção animal. E que a OTVM foi viável e exeqüível para a espécie ovina, não provocando também hemorragias, estresse, desconforto doloroso e perda de peso nos animais, apesar do tempo cirúrgico ter sido maior que nas outras técnicas laparoscópicas / Abstract: The castration of females is important in animal production. However, there are few techniques of ovariectomy described in small ruminants. Thus, the aim of this study was propose alternative techniques of ovariectomy by laparoscopy and evaluate the painful discomfort of the animals and consequently decrease in production, the feasibility and execution time. Therefore, at a first moment was described and compared the ovariectomy by laparotomy (OL), video-assisted (OVA) and total laparoscopic (OTV) in Santa Ines adult ewes, evaluating the transoperative and postoperative, and the stress caused to females for each procedure. In a second moment, aimed to develop and describe a technique for ovariectomy by laparoscopy using one portal and a ligation system pre-assembled (OTVM), evaluating their feasibility, the painful discomfort and the inflammatory process caused in ewes in the same breed. It was concluded that the OVA and OTV techniques had a great advantage compared to OL, once they are minimally invasive procedures, of rapid implementation and provide a minimal discomfort and great recovery of ewes, being recommended since they cause a minimal stress and decrease in animal production. The OTVM was viably and feasibly to the ovine species, not causing bleeding, stress, painful discomfort and weight loss in animals, although the surgical time have been greater than in other laparoscopic techniques / Mestre
28

Terminação de cordeiros com cana-de-açúcar in natura ou hidrolisada com óxido de cálcio em ambientes aeróbico e anaeróbico /

Endo, Viviane. January 2012 (has links)
Orientador: Americo Garcia da Silva Sobrinho / Banca: Acyr Wanderley de Paula Freitas / Banca: Hirasilva Borba / Resumo: Foram utilizados 24 cordeiros Ile de France confinados dos 15 kg aos 32 kg de peso corporal em baias individuais com controle diário do alimento fornecido e das sobras. Os tratamentos, IN: cana-de-açúcar in natura + concentrado, AER: cana-de-açúcar hidrolisada com 0,6% de óxido de cálcio (CaO) em ambiente aeróbico + concentrado e ANA: cana-de-açúcar hidrolisada com 0,6% de CaO em ambiente anaeróbico + concentrado em um delineamento inteiramente casualizado, com oito repetições cada tratamento. Cordeiros alimentados com cana-de-açúcar hidrolisada em ambiente anaeróbico apresentaram maior balanço de nitrogênio (29,46 g/dia e 2,80 g/kg0,75/dia), teor de nitrogênio absorvido (2,98 g/kg0,75/dia), teor de vermelho (a*) aos 45 minutos (10,48) e extrato etéreo (2,77%) no músculo Longissimus lumborum. O maior coeficiente de digestibilidade da fibra em detergente neutro corrigido para cinzas e proteína foi observado para cordeiros alimentados com cana-de-açúcar hidrolisada (aeróbico, 51,70% ou anaeróbico, 53,75%). O maior comprimento da perna in vivo (32,21 cm), menor altura do posterior (55,23 cm) e perdas na dissecação do lombo (1,83%) foram encontrados para cordeiros terminados com cana-de-açúcar hidrolisada em ambiente aeróbico. Menor teor de gordura intermuscular (4,77%) e peso corporal vazio (24,84 kg) foram observados para cordeiros alimentados com cana-de-açúcar in natura. O fornecimento da cana-de-açúcar na forma in natura se torna viável por dispensar o processo de preparo da solução da calda e do revolvimento para homogeneização dos amontoados de cana-de-açúcar, além de não haver necessidade da compra do agente alcalinizante / Abstract: It were used 24 lambs Ile de France, non-castrated, fed with diets containing in nature or hydrolyzed sugar cane in aerobic and anaerobic environments on a roughage: concentrate ratio, 50:50. The lambs were confined to 15 kg body weight, which received the diet in individual stalls in the trough, with control of food offered and the leftovers, and were slaughtered at 32 kg body weight. Lambs fed with hydrolyzed sugar cane in anaerobic environment had higher nitrogen balance (29.46 g / day and 2.80 g/kg0, 75/day), ratio of nitrogen absorbed (2.98 g/kg0, 75/day), level of value for red (a*) at 45 minutes (10.48) and ether extract (2.77%) of Longissimus lumborum muscle. The higher digestibility of neutral detergent fiber corrected for ash and protein was observed for lambs fed with hydrolyzed sugar cane independently of the environment of hydrolysis (aerobic, 51.70% or anaerobic, 53.75%). There was a greater length of leg in vivo (32.21 cm), smaller posterior (55.23 cm) and loss (1.83%) for lambs fed with hydrolyzed sugar cane in aerobic environment. Lower content of intermuscular fat (4.77%) and empty body weight (24.84 kg) for lambs fed sugar cane in nature. The hydrolyzed sugar cane provided better utilization of the fibers, but did not affect performance of animals in nature sugar cane in lambs feeding was shown to increase the quantitative traits in vivo of the lambs, but did not improve and/or damaged in carcass quantitative traits when compared with treatment with hydrolyzed sugar cane, so the use of hydrolyzed sugar cane is feasible to waive daily cuts, consequently, reduces workmanship. The supply of in nature sugar cane becomes feasible to waive the process of the preparation of the solution and revolving for homogenization of the piles of sugar cane and there is no need to purchase the alkalizing agent / Mestre
29

Molecular Cloning, In Vitro Expression, and Functional Characterization of an Ovine Gastrointestinal Peptide Transporter (oPepT1)

Pan, YuanXiang 26 February 2000 (has links)
We reported the primary structure, tissue distribution, and in vitro functional characterization of a peptide transporter, oPepT1, from ovine intestine. The ovine intestinal oPepT1 cDNA was 2,829 bp long encoding a protein of 707 amino acid residues with an estimated molecular size of 79 kDa, and a pI of 6.57. The cDNA contained a 79-bp 5' untranslated sequence and a 630-bp 3' untranslated sequence. The proposed oPepT1 protein was 77.9, 81.3, and 82.6 percent identical to PepT1 from rabbit, rat, and human, respectively. High stringency northern blot analysis demonstrated that oPepT1 is expressed strongly in the small intestine, at lower levels in the omasum, and at much lower levels in the rumen, but is not expressed in liver and kidney. The presence of the peptide transporter in the forestomach at such levels could provide amino acid nitrogen for the ruminant in a nutritionally significant manner. Transport function of oPepT1 was assessed by expressing oPepT1 in Xenopus oocytes using a two-electrode voltage-clamp technique. Overall, the in vitro transport characteristics of oPepT1 expressed in oocytes were similar to those of PepT1 from other species. The transport process is electrogenic and pH-dependent, but independent of Na+, Cl-, and Ca2+. It displayed a broad substrate specificity that transported neutral and charged dipeptides and tripeptides. All dipeptides and tripeptides examined evoked inward currents in a saturable manner, with an affinity constant (Kt) ranging from 20 mM to .6 mM for dipeptides and .15 to 3.0 mM for tripeptides. No responses were detected from tetrapeptides or free amino acids. Although many of the properties displayed by oPepT1 were similar to those of PepT1 from other species, some differences were noted. First, the isoelectric point of oPepT1 was lower than that of others, but the oPepT1 protein appeared to have the same biological activity as that of others at a physiological pH. Second, more potential phosphorylation sites for protein kinases were present in oPepT1. Third, compared with PepT1 from other species, oPepT1 has more negatively charged amino acids at its C-terminus. / Ph. D.
30

Maturation of Cortisol Responses to Adrenocorticotropic Hormone in Twin Fetal Sheep in Vivo

Block, William A., Draper, Michael L., Rose, James C., Schwartz, Jeffrey 01 January 1999 (has links)
OBJECTIVE: Adrenal steroidogenesis is important for maturation of fetal organ systems and plays a role in triggering parturition in ovine pregnancies. Studies have suggested a differential increase in baseline cortisol between twin gestations near term. Our aim was to further delineate the mechanisms responsible for the differences between the hypothalamic- pituitary-adrenal axes of twin fetuses in vivo. STUDY DESIGN: Surgery was performed on pregnant ewes (n = 6) with twin gestations to implant fetal vascular catheters. After recovery but while the subjects were resting, plasma cortisol concentrations were similar in both fetuses. Fetuses received, intravenously, boluses of adrenocorticotropic hormone at 2 doses, and plasma samples were obtained for analysis of the cortisol response. This stimulation by adrenocorticotropic hormone was then repeated in the same fetuses approximately 4 days later, after the increase of resting daily cortisol values in one but not the other fetus. RESULTS: Cortisol responses to adrenocorticotropic hormone before changes in daily resting cortisol concentrations were indistinguishable between twins. However, after separation of daily resting cortisol values, fetuses in group A (elevated resting cortisol concentration) demonstrated a significantly increased response to stimulation by adrenocorticotropic hormone. CONCLUSION: These results suggest a differential development in response to stimulation by adrenocorticotropic hormone between twin fetuses in vivo as the mechanism responsible for the asynchronous elevation of one twin's resting plasma cortisol concentration.

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