RESUMO
The impact of temperature-controlled smoldering smoking conditions on the accumulations of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs) in Frankfurter-type sausages was investigated. Depending on the temperature, smoking can be divided into two phases: an unstable pyrolysis stage (≈ 200 s) and a stable pyrolysis stage (>200 s), which had different effects on hazardous substances contents. The unstable pyrolysis stage, which contributed 66.9 â¼ 89.6% of PAH accumulations by comparing with sausages smoked for 15 min, has significant impact on high PAH residues. By contrast, the contents of HAs showed steady increase trends with smoking time. Few types of free-HAs with low concentrations (3.05 â¼ 22.9 ng/g DW), but more types of bound-HAs with much higher levels (10.8 â¼ 396 ng/g DW) were found. In addition, the formation of some HAs followed the first-order reaction model. However, the detailed formation mechanisms of PAHs and HAs under temperature-controlled smoldering smoking conditions remain to be studied.
Assuntos
Produtos da Carne , Hidrocarbonetos Policíclicos Aromáticos , Hidrocarbonetos Policíclicos Aromáticos/química , Temperatura , Produtos da Carne/análise , Aminas , FumarRESUMO
Gq-protein is located at the convergent point in signal transduction pathways leading to vascular remodeling. The carboxyl terminus of Gα-subunit plays a vital role in G-protein-receptor interaction. The present study was designed to explore the effects of a synthetic Gαq carboxyl terminus imitation peptide, namely GCIP-27, on vascular smooth muscle cells (VSMC) in vitro and vascular remodeling in spontaneous hypertensive rats (SHR). Hyperplasia and hypertrophy of VSMC wre determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, [(3)H]-thymidine and [(3)H]-leucine incorporation, and [Ca(2+)](i) was measured with Fluo-3/AM staining. Systolic blood pressure (SBP), the ratio of media thickness to lumen diameter (MT/LD) of aorta, collagen content, and phospholipase C activity in aorta were measured in SHR. GCIP-27 (3-100 µg/l) significantly decreased proliferation activity, protein content, incorporation of [(3)H]-thymidine and [(3)H]-leucine, and [Ca(2+)](i) level in VSMC. SBP, MT/LD, collagen content, and phospholipase C activity in aorta of SHR were decreased significantly in GCIP-27 (7, 20, 60 µg/kg)-treated groups and losartan (6 mg/kg) group compared with vehicle group. In conclusion, GCIP-27 could inhibit vascular remodeling effectively in vitro and in vivo.
Assuntos
Aorta/patologia , Cardiotônicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/uso terapêutico , Hipertensão/patologia , Hipertrofia/patologia , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Peptídeos/farmacologia , Células 3T3 , Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Aorta/citologia , Aorta/metabolismo , Aorta/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial , Cálcio/análise , Cardiotônicos/uso terapêutico , Técnicas de Cultura de Células , Colágeno/metabolismo , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/fisiologia , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertrofia/fisiopatologia , Losartan/farmacologia , Masculino , Camundongos , Terapia de Alvo Molecular , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Distribuição Aleatória , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ratos Wistar , Sais de Tetrazólio , Tiazóis , Fosfolipases Tipo C/metabolismo , Vasoconstritores/farmacologiaRESUMO
The G(q)-protein is located at the convergent point in the signal transduction pathway that leads to ventricular remodelling. In G-protein signalling pathways, the carboxyl terminus of the G(alpha)-subunit plays a vital role in G-protein-receptor interaction. The aim of the present study was to explore the effects of a synthetic G(alphaq) carboxyl terminus imitation peptide, namely GCIP-27, on left ventricular (LV) remodelling and blood pressure in spontaneous hypertensive rats (SHR). In the present study, 10, 30 or 90 microg/kg, i.p., GCIP-27 was administered for 8 weeks to SHR. In addition, another two groups of SHR were treated with either 6 mg/kg losartan or vehicle (saline). Wistar-Kyoto rats were used as controls. Systolic blood pressure (SBP) was measured using the standard tail-cuff method once every 2 weeks. At the end of the experiment, the LV mass index (LVMI) was evaluated. In addition, LV structure and function, collagen content, microstructure and ultrastructure were examined using echocardiography, the hydroxyproline assay, routine light microscopy and transmission electron microscopy, respectively. In the losartan- and GCIP-27 (10, 30 and 90 microg/kg)-treated groups, SBP was decreased significantly compared with that of the vehicle (saline) group. However, even at the highest concentration used, the hypotensive effect of GCIP-27 was weaker than that of losartan. For example, after 8 weeks treatment, SBP had decreased by 30.4% in the losartan-treated group compared with decreases of 10.5, 13.1 and 18.5% in the 10, 30 and 90 microg/kg GCIP-27-treated groups, respectively. Both GCIP-27 (10, 30 and 90 microg/kg) and losartan (6 mg/kg) significantly reduced LV posterior wall thickness, the thickness of the interventricular septum, collagen content and LVMI, with the effects of GCIP-27 at all three concentrations tested being greater than those of losartan. In conclusion, GCIP-27 effectively attenuates LV remodelling in SHR and the antiremodelling effect may not be dependent entirely on decreases in blood pressure.