RESUMO
The effects of methoprene, a juvenile hormone analogue (JHA), on Trypanosoma cruzi bloodstream trypomastigotes (Tulahuen strain, Tul 2 stock) were studied. It was observed that 150microM of methoprene in in vitro experiments cause cellular death of T. cruzi. In contrast, methoprene was not able to clear bloodstream trypomastigotes in in vivo experiments, but it was observed a decrease of parasitemia levels of infected mice treated with 200microg of methoprene/mouse/day during 5 days. According to these results and the low toxicity of methoprene, we suggest that this compound will serve as an effective agent to sterilize blood for transfusions.
Assuntos
Doença de Chagas/tratamento farmacológico , Metoprene/farmacologia , Parasitemia/tratamento farmacológico , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Transfusão de Sangue/normas , Hormônios Juvenis/farmacologia , Hormônios Juvenis/uso terapêutico , Masculino , Metoprene/uso terapêutico , Camundongos , Esterilização/métodos , Tripanossomicidas/uso terapêuticoRESUMO
The present review assesses the phylogenetic history of information molecules (bioregulators pheromones, hormones, neuroactive compounds), receptors, transducers, second messengers) in uni- and multicellular organisms. Transitional stages between contemporary endocrine secretions including hormones and neuroactive materials, and primogenial exocrine compounds (pheromones) are proposed. Severalhypotheses have been developed to explain the origin and evolution of bioregulator/receptor units. Finally, how these primordial information molecules have either been co-opted or have changed their function during the course of biological evolution is analysed.
Assuntos
Evolução Biológica , Fatores Biológicos/fisiologia , Glândulas Endócrinas/fisiologia , Filogenia , Sequência de Aminoácidos , Animais , Fatores Biológicos/química , HumanosRESUMO
The effects of juvenile hormone-III (JH-III) and the juvenile hormone analogues (JHA) methoprene and fenoxycarb on the growth and macromolecular biosynthesis in Trypanosoma cruzi were studied in vitro. It was observed that JH-III and JHA blocked growth and 3H-thymidine incorporation without killing the cells within certain concentrations (< or = 1 x 10(-4) M), but they caused cellular death at concentrations over 1 x 10(-3) M. The inhibitory effect on growth was partially reversible. On the other hand, the inhibitory action of JH-III, methoprene and fenoxycarb was an unspecific effect according to the results obtained with Leishmania mexicana mexicana (promastigotes) and human peripheral blood lymphocytes. The JHA have a good possibility of being used in the control of trypanosomiasis.
Assuntos
Carbamatos/farmacologia , Hormônios Juvenis/farmacologia , Leishmania mexicana/efeitos dos fármacos , Metoprene/farmacologia , Fenilcarbamatos , Trypanosoma cruzi/efeitos dos fármacos , Animais , DNA de Protozoário/biossíntese , DNA de Protozoário/efeitos dos fármacos , Humanos , Inseticidas/farmacologia , Leishmania mexicana/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Linfócitos/parasitologia , Biossíntese de Proteínas , Precursores de Proteínas/efeitos dos fármacos , Precursores de Proteínas/metabolismo , Proteínas/efeitos dos fármacos , Precursores de RNA/efeitos dos fármacos , Precursores de RNA/metabolismo , RNA de Protozoário/biossíntese , RNA de Protozoário/efeitos dos fármacos , Timidina/metabolismo , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
The effects of juvenile hormone-III (JH-III) and the JH analogue 2-(4-phenoxyphenoxy)-ethoxyte-trahydropiran on testicular steroidogenesis were studied. By using cultured MA-10 Leydig tumor cells as a model, these compounds were found to be potent inhibitors of LH/hCG steroidogenic action in a dose-dependent manner. Scatchard plot analysis of the binding data indicated that the JH analogue did not significantly alter the affinity nor the number of hCG binding sites, as well as GTP binding to plasma membranes. JH analogue inhibited the stimulatory action of both cholera toxin and forskolin on cAMP production and the concomitant steroidogenic response. JH analogue inhibited (Bu)2cAMP-stimulated progesterone synthesis, indicating that a process downstream to the adenylyl cyclase in the steroidogenic pathway is also affected.
Assuntos
Hormônios Juvenis/farmacologia , Células Intersticiais do Testículo/metabolismo , Progesterona/biossíntese , Animais , Linhagem Celular , Toxina da Cólera/farmacologia , Gonadotropina Coriônica/metabolismo , Gonadotropina Coriônica/farmacologia , AMP Cíclico/metabolismo , Guanosina Trifosfato/metabolismo , Masculino , Mamíferos , Transdução de Sinais/efeitos dos fármacosRESUMO
A comparative study was conducted on the molecular weight, chemical composition, and immunological identity of vitellin (VN) from Triatominae species. VN is a lipoglycophosprotein: 12.76% carbohydrates, 12.53% lipids, and 0.6% phosphorus of the protein mass. Native VN shows one band of 310 kDa by gel filtration. VN shows a main band of 175 kDa by SDS-PAGE coincident with a vitellogenin (VG) band. Amino acid composition was very similar in the four species tested: T.infestans, T.pallidipennis, R.prolixus and D.maximus. T.infestans VN-VG has a total immunological identity with D.maximus female haemolymph and egg homogenates.
Assuntos
Triatominae/química , Vitelogeninas/química , Aminoácidos/análise , Animais , Eletroforese em Gel de Poliacrilamida , Feminino , Masculino , Peso Molecular , Vitelogênese , Vitelogeninas/imunologia , Vitelogeninas/isolamento & purificaçãoRESUMO
A comparative study was conducted on the molecular weight, chemical composition, and immunological identity of vitellin (VN) from Triatominae species. VN is a lipoglycophosprotein: 12.76
carbohydrates, 12.53
lipids, and 0.6
phosphorus of the protein mass. Native VN shows one band of 310 kDa by gel filtration. VN shows a main band of 175 kDa by SDS-PAGE coincident with a vitellogenin (VG) band. Amino acid composition was very similar in the four species tested: T.infestans, T.pallidipennis, R.prolixus and D.maximus. T.infestans VN-VG has a total immunological identity with D.maximus female haemolymph and egg homogenates.
RESUMO
A comparative study was conducted on the molecular weight, chemical composition, and immunological identity of vitellin (VN) from Triatominae species. VN is a lipoglycophosprotein: 12.76
carbohydrates, 12.53
lipids, and 0.6
phosphorus of the protein mass. Native VN shows one band of 310 kDa by gel filtration. VN shows a main band of 175 kDa by SDS-PAGE coincident with a vitellogenin (VG) band. Amino acid composition was very similar in the four species tested: T.infestans, T.pallidipennis, R.prolixus and D.maximus. T.infestans VN-VG has a total immunological identity with D.maximus female haemolymph and egg homogenates.
