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1.
Drug Alcohol Depend Rep ; 7: 100162, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37159814

RESUMO

Background: Multimorbidity is linked to worse health outcomes than single health conditions. However, recent studies show that obesity may reduce the risk of developing substance use disorders (SUDs), particularly in vulnerable populations. We investigated how comorbid obesity and tobacco use disorder (TUD) relate to the risk of SUDs and psychiatric conditions. Methods: Data was used from 36,309 individuals who completed the National Epidemiological Survey on Alcohol and Related Conditions - Wave III. Individuals who met the DSM-5 criteria for TUD in the last year were defined as the TUD group. Obesity was defined as having a body mass index (BMI) greater than 30 kg/m2. Using this information, individuals were grouped into categories, with people being identified as either having obesity, TUD, both obesity and TUD, or not having either obesity or TUD (comparison). Groups were compared against their comorbid diagnoses of either an additional SUD or psychiatric conditions. Results: Controlling for demographic characteristics, we found that individuals with obesity including those individuals with TUD, had lower rates of comorbid SUD diagnosis than individuals with TUD alone. Additionally, individuals with combined TUD and obesity, and those with TUD alone, had the highest rates of comorbid psychiatric disorder diagnosis. Conclusions: The current study aligns with previous research suggesting that obesity may reduce risk of substance use disorders, even in individuals who have other risk factors promoting harmful substance use (e.g., tobacco use). These findings may inform targeted intervention strategies for this clinically relevant subpopulation.

2.
Behav Res Ther ; 59: 82-93, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24972492

RESUMO

Several theories have proposed that negative affect (NA) plays a large role in the maintenance of substance use behaviors - a phenomenon supported in laboratory-based and clinical studies. It has been demonstrated that mindfulness meditation can improve the regulation of NA, suggesting that mindfulness may be very beneficial in treating problematic substance use behavior. The current study tested whether a brief mindfulness meditation would lower levels of NA, increase willingness to experience NA, lower urges to drink, and increase time to next alcoholic drink in a sample of at-risk college student drinkers (N = 207). Participants were randomized to one of three brief interventions (mindfulness, relaxation, or control) followed by an affect manipulation (negative or neutral stimuli). Affect and urge were measured prior to intervention (Time 1 [T1]), after intervention but prior to affect manipulation (Time 2 [T2]), and immediately after the affect manipulation (Time 3 [T3]). Levels of mindfulness and relaxation were assessed from T1-T3. The additional measures of willingness to continue watching NA images and time to next alcoholic drink were examined at T3. Results indicated that the mindfulness intervention increased state mindfulness and relaxation, and decreased NA immediately following the mindfulness intervention. However, the mindfulness intervention did not influence responses to NA induction on any of the outcome variables at T3. One potential explanation is that the mindfulness intervention was not robust enough to maintain the initial gains made immediately following the intervention.


Assuntos
Afeto , Consumo de Bebidas Alcoólicas/terapia , Fissura , Atenção Plena , Estudantes/psicologia , Universidades , Feminino , Humanos , Masculino , Psicoterapia Breve , Relaxamento/psicologia , Terapia de Relaxamento , Fatores de Tempo , Adulto Jovem
3.
Placenta ; 35(6): 351-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24731730

RESUMO

INTRODUCTION: The pro-inflammatory mediator and potent vasoconstrictor Endothelin-1 (ET-1) is known to be expressed in the placenta. We have recently demonstrated that very low, non-toxic doses of carbon monoxide (CO), prevented infection-induced preterm birth in mice. However the effect(s) of CO on human gestational tissues is yet to be fully explored. We hypothesize that CO will have a protective role against inflammation-induced E. coli by down-regulating the ET axis in placental explants. METHODS: Twenty placentas from elective termination of pregnancy in the second trimester were analyzed with or without exposure to heat killed E. coli over the course of 30 h. Placental ET-1, along with its biologically inactive precursor Big ET-1, and Endothelin Converting Enzyme-1 (ECE-1, responsible for the cleavage of Big ET-1 to ET-1), were analyzed by ELISA. Gene expression for ET-1 (EDN1), ECE-1 and the ETA receptor (EDNRA) were analyzed using qPCR. Localization of ET-1 expression was also demonstrated using immunohistochemistry. RESULTS: E. coli significantly increased ET-1 transcription and secretion of BIG ET-1 and ET-1 in a time dependant manner which was ameliorated when exposed to CO at later time points. In the presence of CO, mRNA levels of ECE-1 were significantly reduced at 3 and 24 h, while EDNRA was significantly reduced at 6 and 18 h. CONCLUSIONS: Up-regulation of ET-1 production in human placenta in the setting of infection can be attenuated by low doses of CO. Our results further explore the anti-inflammatory and regulatory mechanism(s) of CO on the ET axis components at the maternal fetal interface.


Assuntos
Monóxido de Carbono/farmacologia , Endotelina-1/metabolismo , Escherichia coli/fisiologia , Placenta/química , Placenta/efeitos dos fármacos , Anti-Inflamatórios , Monóxido de Carbono/administração & dosagem , Endotelina-1/biossíntese , Endotelina-1/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Gravidez , Segundo Trimestre da Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais
4.
Placenta ; 33(9): 745-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22749501

RESUMO

Polybrominated diphenyl ether(s) (PBDE) are ubiquitous environmental contaminants that bind and cross the placenta but their effects on pregnancy outcome are unclear. It is possible that environmental contaminants increase the risk of inflammation-mediated pregnancy complications such as preterm birth by promoting a proinflammatory environment at the maternal-fetal interface. We hypothesized that PBDE would reduce IL-10 production and enhance the production of proinflammatory cytokines associated with preterm labor/birth by placental explants. Second-trimester placental explants were cultured in either vehicle (control) or 2 µM PBDE mixture of congers 47, 99 and 100 for 72 h. Cultures were then stimulated with 10(6) CFU/ml heat-killed Escherichia coli for a final 24 h incubation and conditioned medium was harvested for quantification of cytokines and PGE(2). COX-2 content and viability of the treated tissues were then quantified by tissue ELISA and MTT reduction activity, respectively. PBDE pre-treatment reduced E. coli-stimulated IL-10 production and significantly increased E. coli-stimulated IL-1ß secretion. PBDE exposure also increased basal and bacteria-stimulated COX-2 expression. Basal, but not bacteria-stimulated PGE(2), was also enhanced by PBDE exposure. No effect of PBDE on viability of the explants cultures was detected. In summary, pre-exposure of placental explants to congers 47, 99, and 100 enhanced the placental proinflammatory response to infection. This may increase the risk of infection-mediated preterm birth by lowering the threshold for bacteria to stimulate a proinflammatory response(s).


Assuntos
Citocinas/biossíntese , Éteres Difenil Halogenados/farmacologia , Inflamação/imunologia , Placenta/efeitos dos fármacos , Placenta/imunologia , Ciclo-Oxigenase 2/análise , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/biossíntese , Escherichia coli/imunologia , Feminino , Humanos , Inflamação/metabolismo , Interleucina-10/biossíntese , Interleucina-1beta/biossíntese , Placenta/metabolismo , Gravidez , Nascimento Prematuro/etiologia , Técnicas de Cultura de Tecidos
5.
Placenta ; 26(8-9): 661-71, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16085045

RESUMO

OBJECTIVE: Microarray analysis was used to characterize the labor-selective transcriptome of the human myometrium during labor. One highly up-regulated transcript, monocyte chemotactic protein-1 (MCP-1), was further characterized. METHODS: Expression of MCP-1 was evaluated in the myometrium, the placenta, the gestational membranes (GM) and the amniotic fluid (AF) by real time RT-PCR, Northern blot analysis and ELISA. The level of immunoreactive (IR) MCP-1 content of primary myometrial cultures treated with inflammatory cytokines was quantified by ELISA. RESULTS: Up-regulation of the myometrial MCP-1 transcript in term laboring patients was demonstrated by microarray and confirmed by real time (RT)-PCR and Northern blot analysis. Increased MCP-1 transcripts were demonstrated in GM during term labor. The IR content of myometrial MCP-1 was increased during term labor and in the AF from patients experiencing preterm delivery. Levels of IR MCP-1 increased in myometrial cultures in response to interleukin 1-beta. CONCLUSION: The expression of myometrial MCP-1 was significantly increased during term labor and was similarly increased in vitro in response to interleukin 1-beta, a pro-inflammatory substance known to play a role in preterm birth. The increased IR content of MCP-1 within the AF preceding preterm delivery may render this protein a useful predictor of preterm birth.


Assuntos
Quimiocina CCL2/metabolismo , Membranas Extraembrionárias/metabolismo , Trabalho de Parto Prematuro/metabolismo , Placenta/metabolismo , Regulação para Cima , Adulto , Líquido Amniótico/metabolismo , Northern Blotting , Células Cultivadas , Quimiocina CCL2/genética , Feminino , Perfilação da Expressão Gênica , Humanos , Interleucina-1/farmacologia , Miométrio/citologia , Miométrio/efeitos dos fármacos , Miométrio/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Am J Reprod Immunol ; 45(5): 266-72, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11432401

RESUMO

PROBLEM: During pregnancy, the endometrium of the ewe secretes a progesterone-induced member of the serpin superfamily of serine proteinase inhibitors called ovine uterine serpin (OvUS) that has immunosuppressive properties. METHOD: Review of the literature. RESULTS AND CONCLUSIONS: OvUS inhibits a wide variety of immune responses, including mixed lymphocyte reaction, mitogen-stimulated lymphocyte proliferation, and T cell-dependent antibody production. Recent data have suggested that OvUS functions by inhibiting protein kinase C and interleukin-2-mediated events. OvUS and similar genes present in cattle and pigs diverged from other serpins prior to the divergence of artiodactyls. Since this time, the serpins have apparently undergone adaptive evolution that has led to a conformational state and biological functions distinct from prototypical serpins. Thus, it is likely that these proteins have an important role in the reproductive biology of Artiodactyla. Several lines of evidence suggest that, in sheep, OvUS functions to mediate the immunosuppressive effects of progesterone and prevent immunological rejection of the fetal allograft.


Assuntos
Serpinas/química , Serpinas/imunologia , Animais , Evolução Biológica , Feminino , Tolerância Imunológica , Troca Materno-Fetal/imunologia , Modelos Biológicos , Filogenia , Gravidez , Conformação Proteica , Serpinas/genética , Ovinos
7.
Biochim Biophys Acta ; 1479(1-2): 37-51, 2000 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11004528

RESUMO

Experiments were performed to examine the relationship between the structure and function of ovine uterine serpin (OvUS). Limited proteolytic digestion of OvUS caused cleavage of the 55-57 kDa OvUS to a 42 kDa product nearly identical in molecular weight to a naturally-occurring breakdown product of OvUS. N-terminal amino acid sequencing and MALDI-MS revealed that, unlike other serpins, OvUS was preferentially cleaved at about 70 amino acids upstream of the putative reactive center loop. Analysis of the partially-digested protein by gel filtration chromatography suggested that the C-terminal fragment of the protein was still associated under nondenaturing conditions. Partial digestion of OvUS had no effect on the protein's secondary structure, thermal stability, ability to bind lymphocytes or pepsin, or inhibitory activity towards pepsin or mitogen-induced lymphocyte proliferation. In contrast, mild denaturation of OvUS with 0.5 M guanidine HCl increased thermal stability. Unlike for other serpins, the increase in thermal stability was lost upon removal of the denaturant. Incubation of OvUS with 100 fold molar excess of a peptide corresponding to the putative P(14)-P(2) region of the RCL for 24 h at 37 degrees C to induce binary complex formation had no effect on its secondary structure and did not alter the biological activity of the protein. Synthetic peptides corresponding to the putative P(14)-P(2) region and the P(7)-P(15') region of the RCL were not inhibitory to pepsin activity or lymphocyte proliferation. Taken together, these results indicate that the conformation of OvUS is distinct from the prototypical serpin because conditions that lead to the large-scale conformational change in other serpins such as antithrombin III and alpha(1)-antitrypsin do not cause similar changes in OvUS. Moreover, the putative RCL does not seem to contain the activity required to inhibit lymphocyte proliferation or pepsin activity.


Assuntos
Serpinas/química , Útero/química , Sequência de Aminoácidos , Animais , Divisão Celular , Cromatografia em Gel , Feminino , Hidrólise , Linfócitos/citologia , Linfócitos/metabolismo , Dados de Sequência Molecular , Pepsina A/metabolismo , Conformação Proteica , Desnaturação Proteica , Serpinas/metabolismo , Ovinos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Útero/metabolismo
8.
J Exp Zool ; 288(2): 165-74, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10931499

RESUMO

A bioinformatics analysis was conducted on the four members of the uterine serpin (US) family of serpins. Evolutionary analysis of the protein sequences and 86 homologous serpins by maximum parsimony and distance methods indicated that the uterine serpins proteins form a clade distinct from other serpins. Ancestral sequences were reconstructed throughout the evolutionary tree by parsimony. These suggested that some branches suffered a high ratio of nonsynonymous to synonymous mutations, suggesting episodes of adaptive evolution within the serpin family. Analysis of the sequences by neutral evolutionary distance methods suggested that the uterine serpins diverged from other serpins prior to the divergence of the mammals from other vertebrates. The porcine uterine serpins are paralogs that diverged from a single common ancestor within the Sus genus after pigs separated from other artiodactyls. The uterine serpins contain several protein kinase C and tyrosine kinase phosphorylation sites. These sites may be important for the lymphocyte-inhibitory activity of OvUS if, like other basic proteins, OvUS can cross the cell membrane of an activated lymphocyte. Internalized OvUS could serve as an alternative target to protein kinases important for the mitogenic response to antigens.


Assuntos
Evolução Molecular , Filogenia , Serpinas/genética , Útero/fisiologia , Sequência de Aminoácidos , Animais , Feminino , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Biblioteca de Peptídeos , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Serpinas/química , Software
9.
Proc Soc Exp Biol Med ; 223(1): 75-81, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10632964

RESUMO

During pregnancy, the endometrium of the ewe secretes large amounts of a progesterone-induced protein of the serpin superfamily of serine proteinase inhibitors called ovine uterine serpin (OvUS). This protein inhibits lymphocyte proliferation in response to concanavalin A (ConA), phytohemagglutinin (PHA), or mixed lymphocyte reaction. The purpose of these experiments was to characterize the mechanism by which OvUS inhibits lymphocyte proliferation. Ovine US caused dose-dependent inhibition of lymphocyte proliferation induced by phorbol myristol acetate (PMA), an activator of protein kinase C. The PHA-induced increase in CD25 expression was inhibited in peripheral blood mononuclear leukocytes (PBML) by OvUS. However, no effect of OvUS on Con A-induced expression of CD25 was observed. Further analysis using two-color flow cytometry revealed that OvUS inhibited ConA-induced expression of CD25 in gammadelta-TCR- cells but not gammadelta-TCR+ cells. Stimulation of PBML for 14 hr with ConA resulted in an increase in steady state amounts of interleukin-2 (IL-2) mRNA that was not inhibited by OvUS. Ovine US was also inhibitory to lymphocyte proliferation induced by human IL-2. Results suggest that OvUS acts to inhibit lymphocyte proliferation by blocking the upregulation of the IL-2 receptor and inhibiting IL-2-mediated events. Lack of an effect of OvUS on ConA-stimulated CD25 expression in gammadelta-TCR+ cells may reflect a different mechanism of activation of these cells or insensitivity to inhibition by OvUS.


Assuntos
Interleucina-2/genética , Interleucina-2/farmacologia , Ativação Linfocitária/imunologia , Linfócitos/imunologia , Serpinas/farmacologia , Útero/fisiologia , Animais , Células Cultivadas , Concanavalina A , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Humanos , Interleucina-2/biossíntese , Ativação Linfocitária/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Gravidez , RNA Mensageiro/genética , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Interleucina-2/biossíntese , Receptores de Interleucina-2/efeitos dos fármacos , Receptores de Interleucina-2/genética , Serpinas/isolamento & purificação , Ovinos , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/imunologia , Regulação para Cima/efeitos dos fármacos , Útero/imunologia
10.
Biol Reprod ; 61(6): 1644-8, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10570014

RESUMO

Experiments were performed to evaluate the role of transcription in early development of bovine embryos. Two transcription inhibitors-5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) and actinomycin D-were used to test whether 1) the inhibitors alter the rate of early embryonic development and protein synthesis, 2) heat shock increases the steady-state amounts of mRNA for the inducible form of heat shock protein 70 (HSP70) in embryos, and 3) this latter effect is blocked by transcription inhibitors. Addition of either DRB or actinomycin D to culture medium beginning 8 h postinsemination (hpi) reduced the proportion of oocytes that had undergone cleavage by 32-34 hpi. Both transcription inhibitors also reduced the proportion of cleaved embryos that reached the 4-cell stage by 32-34 hpi. Incorporation of (35)S-labeled amino acids into de novo synthesized protein by bovine 2-cell embryos was lower for embryos cultured with DRB. Using reverse transcription-polymerase chain reaction, HSP70 mRNA in 2- and 4-cell embryos was increased by exposure to 42 degrees C. Both inhibitors reduced amounts of HSP70 mRNA at 42 degrees C. Results indicate that bovine embryos can undergo transcription in response to heat shock as early as the 2-cell stage. Moreover, the observations that transcription inhibitors reduce rates of cleavage and early development point out the importance of transcription for development from the earliest period of embryonic life.


Assuntos
Bovinos/embriologia , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário e Fetal , Proteínas de Choque Térmico HSP70/biossíntese , Temperatura Alta , Biossíntese de Proteínas , Transcrição Gênica , Animais , Fase de Clivagem do Zigoto , Dactinomicina/farmacologia , Diclororribofuranosilbenzimidazol/farmacologia , Proteínas de Choque Térmico HSP70/genética , Inibidores da Síntese de Ácido Nucleico/farmacologia , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Am J Reprod Immunol ; 41(6): 428-32, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10392232

RESUMO

PROBLEM: The endometrium of the sheep produces a progesterone-induced member of the serpin superfamily of serine proteinase inhibitors that can inhibit lymphocyte proliferation and reduce natural killer cell activity. Present results indicate that this molecule, called ovine uterine serpin (OvUS), can bind specifically to lymphocytes. METHOD OF STUDY/RESULTS: Biotinylated OvUS bound to peripheral blood lymphocytes in a dose-dependent and saturable manner. Binding was inhibited by OvUS, but not by several other proteins, including serpin-enzyme complex (alpha 1-antitrypsin-trypsin). Heparin blocked binding when added to the binding reaction or when used to pretreat lymphocytes. Both lymphocytes and Madin-Darby bovine kidney (MDBK) cells also bound fluorescein isothiocyanate-labeled OvUS. CONCLUSIONS: Results suggest that OvUS can interact with lymphocytes and other cells through binding to a cell surface molecule. Such binding may indicate that inhibition of lymphocyte activation by OvUS involves 1) binding of OvUS to a cell surface receptor or 2) competitive inhibition of binding between OvUS and a co-activation molecule required for lymphocyte activation.


Assuntos
Glicoproteínas/metabolismo , Linfócitos/enzimologia , Serpinas/metabolismo , Útero/enzimologia , Animais , Ligação Competitiva/imunologia , Bovinos , Linhagem Celular , Feminino , Rim , Ativação Linfocitária/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Ligação Proteica/imunologia , Inibidores de Serina Proteinase/metabolismo , Serpinas/farmacologia , Ovinos , Útero/imunologia
12.
J Anim Sci ; 76(3): 847-9, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9535346

RESUMO

In the use of ANOVA for hypothesis testing in animal science experiments, the assumption of homogeneity of errors often is violated because of scale effects and the nature of the measurements. We demonstrate a method for transforming data so that the assumptions of ANOVA are met (or violated to a lesser degree) and apply it in analysis of data from a physiology experiment. Our study examined whether melatonin implantation would affect progesterone secretion in cycling pony mares. Overall treatment variances were greater in the melatonin-treated group, and several common transformation procedures failed. Application of the Box-Cox transformation algorithm reduced the heterogeneity of error and permitted the assumption of equal variance to be met.


Assuntos
Criação de Animais Domésticos/métodos , Interpretação Estatística de Dados , Projetos de Pesquisa , Análise de Variância , Animais , Dinoprosta/farmacologia , Estro , Feminino , Cavalos , Ovulação , Progesterona/sangue , Reprodutibilidade dos Testes
13.
Theriogenology ; 49(6): 1125-42, 1998 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10732051

RESUMO

The effects of melatonin implant treatment over a 4 wk period at the summer solstice on the transition into and out of the following anovulatory season were evaluated in ovary-intact and ovariectomized mares. Melatonin implants tended to delay the timing of the final ovulation of the breeding season (P = 0.0797) in the ovary-intact mares. Although the decline in LH secretion associated with the end of the breeding season was parallel between treatments and ovarian statuses, the rate of LH secretion, as expressed by its mathematical accumulation, was lower in ovariectomized, melatonin-treated mares than in ovariectomized, control mares suggesting that melatonin administration advanced the offset of the breeding season in ovariectomized mares (P = 0.0001). The first ovulation of the subsequent breeding season was significantly delayed in the melatonin-treated mares as compared with that of control mares (P = 0.0031). During reproductive recrudescence, the time of the onset of the increase in LH secretion was similar among all 4 groups but the patterns of LH secretion were different for each treatment and ovarian status combination (P = 0.0112). Mares with melatonin implants had a slower rate of increase in LH secretion than control mares (P = 0.0001), and ovariectomized mares had a faster rate of LH increase than intact mares (P = 0.0001). These results suggest that melatonin implants during the summer solstice can alter the annual reproductive rhythm in mares and support the concept that endocrine patterns of reproductive recrudescence are not entirely independent of the ovary.


Assuntos
Estro , Cavalos/fisiologia , Melatonina/administração & dosagem , Animais , Implantes de Medicamento , Estradiol/sangue , Estradiol/metabolismo , Estro/efeitos dos fármacos , Estro/fisiologia , Feminino , Análise dos Mínimos Quadrados , Hormônio Luteinizante/sangue , Hormônio Luteinizante/metabolismo , Melatonina/sangue , Ovariectomia/veterinária , Ovário/efeitos dos fármacos , Ovário/metabolismo , Ovário/fisiologia , Ovulação/efeitos dos fármacos , Ovulação/fisiologia , Fotoperíodo , Radioimunoensaio/veterinária , Distribuição Aleatória , Análise de Regressão , Estações do Ano
14.
Theriogenology ; 49(6): 1113-23, 1998 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10732050

RESUMO

The effects of melatonin implant treatment over a four week period on LH, estradiol (E2) and progesterone (P4) secretion during the breeding season were studied in ovary-intact and ovariectomized pony mares. Mares with melatonin implants had significantly higher daytime melatonin concentrations than mares with sharm implants (P = 0.0065). In ovariectomized mares, LH secretion did not differ between mares with melatonin and sham implants. In ovary-intact mares, melatonin implants altered the pattern of LH secretion (P = 0.0023) in such a way that an increase in LH secretion was observed during the periovulatory period. Estradiol and P4 secretion were unaffected by melatonin implants. These results suggest that constant administration of melatonin may enhance the secretion of LH during the periovulatory surge but does not adversely affect E2, P4 or basal LH secretion in mares during the breeding season.


Assuntos
Cavalos/fisiologia , Hormônio Luteinizante/metabolismo , Melatonina/administração & dosagem , Ovário/efeitos dos fármacos , Animais , Implantes de Medicamento , Estradiol/sangue , Estradiol/metabolismo , Feminino , Análise dos Mínimos Quadrados , Modelos Lineares , Hormônio Luteinizante/sangue , Melatonina/sangue , Ciclo Menstrual/efeitos dos fármacos , Ciclo Menstrual/fisiologia , Ovariectomia/veterinária , Ovário/metabolismo , Ovário/fisiologia , Fotoperíodo , Progesterona/sangue , Progesterona/metabolismo , Radioimunoensaio/veterinária , Análise de Regressão , Contagem de Cintilação/veterinária
15.
Theriogenology ; 48(6): 893-906, 1997 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-16728181

RESUMO

The objective of this study was to determine whether supplemental beta-carotene would influence reproductive function in mares maintained on spring and summer pastures and to characterize plasma carotene concentrations during the estrous cycle. Carotene concentrations in plasma did not vary with day of estrous cycle (P = 0.7455). Mares receiving every other day injections of beta-carotene (400 mg; n = 4) or saline (10 ml; n = 4) during proestrus/estrus did not differ in plasma estradiol (E(2)) concentrations (P = 0.6313), follicle development (P = 0.8068), or plasma progesterone (P(4)) concentrations during the following diestrus (P = 0.4954). Moreover, no differences in plasma P(4) concentrations (P = 0.9047) were detected between mares receiving every other day injections of beta-carotene (400 mg; n = 4) or saline (10 ml; n = 4) during diestrus. However, administration of beta-carotene raised plasma carotene concentrations relative to controls when injected during proestrus/estrus (P = 0.0096) and diestrus (P = 0.0099). Pregnancy rates (P = 0.4900) and number of cycles required for pregnancy (P = 0.2880) were similar for mares administered injections of saline (10 ml; n = 37), beta-carotene (400 mg; n = 37), vitamin A (160,000 IU; n = 38), or vitamin A + beta-carotene (160,000 IU + 400 mg; n = 43), on the first or second day of estrus and on the day of breeding. Therefore, these results collectively suggest that supplemental beta-carotene does not affect the reproductive function of mares fed adequate dietary carotene. Whether supplemental beta-carotene would enhance reproductive function in mares on low carotene diets warrants further investigation.

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