Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Braz J Med Biol Res ; 39(5): 581-8, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16648894

RESUMO

It has been reported that mental stress causes abnormality of spermiogram parameters. We investigated the effect of psychological stress on the L-arginine-nitric oxide (NO) pathway. Semen samples were collected from 29 healthy fourth semester medical students just before (stress) and 3 months after (non-stress) the final examinations. Psychological stress was measured by the State Anxiety Inventory questionnaire. After standard semen analysis, arginase activity and NO concentration were measured spectrophotometrically in the seminal plasma. Measurements were made in duplicate. During the stress period, sperm concentration (41.28 +/- 3.70 vs 77.62 +/- 7.13 x 10(6)/mL), rapid progressive motility of spermatozoa (8.79 +/- 1.66 vs 20.86 +/- 1.63%) and seminal plasma arginase activity (0.12 +/- 0.01 vs 0.22 +/- 0.01 U/mL) were significantly lower than in the non-stress situation, whereas seminal plasma NO (17.28 +/- 0.56 vs 10.02 +/- 0.49 micromol/L) was higher compared to the non-stress period (P < 0.001 for all). During stress there was a negative correlation between NO concentration and sperm concentration, the percentage of rapid progressive motility and arginase activity (r = -0.622, P < 0.01; r = -0.425, P < 0.05 and r = -0.445, P < 0.05, respectively). These results indicate that psychological stress causes an increase of NO level and a decrease of arginase activity in the L-arginine-NO pathway. Furthermore, poor sperm quality may be due to excessive production of NO under psychological stress. In the light of these results, we suggest that the arginine-NO pathway, together with arginase and NO synthase, are involved in semen quality under stress conditions.


Assuntos
Arginase/análise , Arginina/metabolismo , Óxido Nítrico Sintase/metabolismo , Sêmen/enzimologia , Espermatozoides/fisiologia , Estresse Psicológico/enzimologia , Adulto , Humanos , Masculino , Reprodutibilidade dos Testes , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Estudantes de Medicina
2.
Braz. j. med. biol. res ; 39(5): 581-588, May 2006. tab, graf
Artigo em Inglês | LILACS | ID: lil-425780

RESUMO

It has been reported that mental stress causes abnormality of spermiogram parameters. We investigated the effect of psychological stress on the L-arginine-nitric oxide (NO) pathway. Semen samples were collected from 29 healthy fourth semester medical students just before (stress) and 3 months after (non-stress) the final examinations. Psychological stress was measured by the State Anxiety Inventory questionnaire. After standard semen analysis, arginase activity and NO concentration were measured spectrophotometrically in the seminal plasma. Measurements were made in duplicate. During the stress period, sperm concentration (41.28 ± 3.70 vs 77.62 ± 7.13 x 10(6)/mL), rapid progressive motility of spermatozoa (8.79 ± 1.66 vs 20.86 ± 1.63 percent) and seminal plasma arginase activity (0.12 ± 0.01 vs 0.22 ± 0.01 U/mL) were significantly lower than in the non-stress situation, whereas seminal plasma NO (17.28 ± 0.56 vs 10.02 ± 0.49 æmol/L) was higher compared to the non-stress period (P < 0.001 for all). During stress there was a negative correlation between NO concentration and sperm concentration, the percentage of rapid progressive motility and arginase activity (r = -0.622, P < 0.01; r = -0.425, P < 0.05 and r = -0.445, P < 0.05, respectively). These results indicate that psychological stress causes an increase of NO level and a decrease of arginase activity in the L-arginine-NO pathway. Furthermore, poor sperm quality may be due to excessive production of NO under psychological stress. In the light of these results, we suggest that the arginine-NO pathway, together with arginase and NO synthase, are involved in semen quality under stress conditions.


Assuntos
Adulto , Humanos , Masculino , Arginase/análise , Arginina/metabolismo , Óxido Nítrico Sintase/metabolismo , Sêmen/enzimologia , Espermatozoides/fisiologia , Estresse Psicológico/enzimologia , Reprodutibilidade dos Testes , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Estudantes de Medicina
3.
Hum Reprod ; 20(9): 2595-600, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15890736

RESUMO

BACKGROUND: It has been reported that there is a relationship between stress and infertility. The mechanisms of stress-related semen quality alterations have not been fully elucidated. In the present study, we investigated the effect of examination stress on seminal glutathione and free sulphydryl content and sperm quality. METHODS: Semen samples were collected from 34 healthy volunteers who were students of medical school in the fourth semester just before (stress period) and 3 months after (non-stress period) their final examinations. Their psychological examination stress was measured by the State Trait Anxiety Inventory (STAI) questionnaire. After standard semen analysis, semen samples were centrifuged at 10 000g for 15 min. Glutathione and free sulphydryl concentration of seminal plasma were measured. RESULTS: During the period of examination stress, the glutathione and free sulphydryl content of seminal plasma and the motility index of spermatozoa were significantly lower, whereas the percentage of morphologically abnormal spermatozoa was higher, than during the non-stress period (P < 0.001, for all). An association between seminal plasma glutathione and motility index was observed at both periods (P < 0.05 and P < 0.01, respectively). CONCLUSIONS: This study demonstrated that glutathione and free sulphydryl levels in seminal plasma decreased in subjects undergoing examination stress. Furthermore, poor sperm quality may be due to loss of glutathione and free sulphydryl content of seminal plasma.


Assuntos
Fertilidade/fisiologia , Glutationa/metabolismo , Sêmen/metabolismo , Estresse Psicológico/metabolismo , Compostos de Sulfidrila/metabolismo , Adulto , Ansiedade/metabolismo , Avaliação Educacional , Humanos , Infertilidade Masculina/metabolismo , Infertilidade Masculina/psicologia , Masculino , Estresse Oxidativo/fisiologia , Estudantes de Medicina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA