RESUMO
This work was carried out to assess the effects of chronic mild stress (CMS) on thyroid function. The CMS model produced an anhedonic effect (reduced preference to sucrose) in Sprague-Dawley and Wistar rats and this effect was reversed by imipramine (IMI) treatment. The effects of CMS on thyroid function were assessed by measuring tT4 (total Thyroxine), tT3 (total Triiodothyronine), TSH (Thyroid Stimulating Hormone) and fT4 (free Thyroxine) serum levels with appropriate immunoassays. CMS increased tT4 and tT3 serum levels in Sprague-Dawley and Wistar rats, but not TSH and fT4 serum levels. Imipramine (IMI) treatment normalized tT4 values. Albumin which binds a fraction of peripheral tT4 and tT3 was also significantly increased in response to CMS, possibly contributing to tT4 and tT3 elevations. The above findings suggest an impact of CMS on thyroid function, especially in tT4 values the changes being reversed with IMI treatment.
Assuntos
Estresse Fisiológico/fisiopatologia , Glândula Tireoide/metabolismo , Animais , Antidepressivos Tricíclicos/farmacologia , Comportamento Animal/efeitos dos fármacos , Doença Crônica , Modelos Animais de Doenças , Ingestão de Alimentos/efeitos dos fármacos , Imipramina/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Albumina Sérica/metabolismo , Especificidade da Espécie , Estresse Fisiológico/sangue , Estresse Fisiológico/tratamento farmacológico , Testes de Função Tireóidea , Glândula Tireoide/efeitos dos fármacos , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangueRESUMO
Insect cell growth can be significantly improved by close attention to the conditions used in the inoculum stages. Initial cell concentration, spent medium carry over and inoculum phase withdrawal significantly influenced the growth kinetics of Spodoptera frugiperda (Sf9) cells. The percentage of cells infected with wild and recombinant baculovirus AcNPV and (in the later case) the beta-galactosidase yield in fresh medium was appreciably affected by the stage of the growth curve that cells were in when infected and by the multiplicity of infection (MOI). However, the cell density at the time of infection and the medium condition showed little direct influence on infectivity. There may, however, be an indirect influence in that these factors determine the relative distribution of cells in the cell cycle. The infectivity is then in turn affected by the relative frequency of cells in the G1, S and G2/M phases. Insect cell specific oxygen uptake rates (1.3-3.4 x 10(-17) mol per cell per s) were essentially similar to or less than those measured for hybridoma cells. However, when Sf9 cells were infected with baculovirus, the specific oxygen uptake rate increased by up to 40%.
