RESUMO
A 37 amino acid cyclic polypeptide has been isolated from the organic extract of the tropical tree Palicourea condensata. Palicourein (1) is the largest of a growing family of plant peptides that contain a cyclized amino acid backbone cross-linked via three internal disulfide bridges. Palicourein inhibits the in vitro cytopathic effects of HIV-1RF infection of CEM-SS cells with an EC50 value of 0.1 microM and an IC50 value of 1.5 microM.
Assuntos
Fármacos Anti-HIV/isolamento & purificação , Ciclotídeos , Peptídeos Cíclicos/isolamento & purificação , Rubiaceae/química , Sequência de Aminoácidos , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Efeito Citopatogênico Viral/efeitos dos fármacos , Dissulfetos/análise , Humanos , Dados de Sequência Molecular , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Conformação Proteica , Árvores/químicaAssuntos
Biomarcadores Tumorais/sangue , Germinoma/sangue , Neoplasias Testiculares/sangue , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo , Diagnóstico Diferencial , Feminino , Germinoma/diagnóstico , Germinoma/terapia , Humanos , Lactente , Masculino , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/terapiaRESUMO
To assess the effects of long-term pressure overload on sympathetic presynaptic components in the left ventricle, young adult male rats were subjected to surgical constriction of the suprarenal abdominal aorta. At 4 and 8 wk postsurgery, but not at 1 wk, left ventricular sympathetic activity, measured by the net fractional norepinephrine (NE) decrease after alpha-methyl-p-tyrosine methyl ester administration, was elevated in the aortic-banded rats. However, left ventricular NE was reduced only at 8 wk. Scatchard analysis of saturation binding of [3H]nisoxetine, a specific ligand for NE uptake sites, determined that left ventricular NE transporter sites were also reduced at 8 wk, suggesting a relationship between a reduced number of uptake sites and loss of NE stores. In contrast, aortic constriction did not reduce neuropeptide Y (NPY), tyrosine hydroxylase, dopamine beta-hydroxylase, nervegrowth factor, and low-affinity nerve growth factor receptors at any time point. Thus long-term pressure overload can cause a selective reduction in ventricular NE stores without a reduction in NPY, a colocalized sympathetic neurotransmitter.
Assuntos
Hipertensão/fisiopatologia , Terminações Pré-Sinápticas/fisiologia , Sistema Nervoso Simpático/fisiopatologia , Simportadores , Função Ventricular Esquerda , Animais , Aorta Abdominal , Sítios de Ligação , Proteínas de Transporte/metabolismo , Fluoxetina/análogos & derivados , Fluoxetina/metabolismo , Ligadura , Masculino , Metiltirosinas/farmacologia , Miocárdio/metabolismo , Neuropeptídeo Y/metabolismo , Norepinefrina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Norepinefrina , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
Neuropeptide Y (NPY), immunoreactive (IR), and tyrosine hydroxylase (TH)-IR nerve fibers were scarce at birth in rat heart, but increased rapidly during the first 2 postnatal weeks, reaching approximately adult levels by the third week. The sequence of development was: interatrial septum and atrial wall, free ventricular wall starting from the epicardium, and finally the atrial appendages and interventricular septum. In ventricles and atrial appendages both fiber types developed similarly. In interatrial septum and atrial walls more NPY-IR than TH-IR fibers were evident, and NPY-IR, but not TH-IR, neurons were detected in intrinsic ganglia. Double-label immunohistochemistry provided further evidence that NPY is located in ventricular and atrial noradrenergic nerves, but is also located in nonnoradrenergic nerves in atria.