Ação do forskolin em diferentes fases da produção in vitro: implicação na meiose oocitária e na vitrificação de embriões bovinos

Pós-graduação em Medicina Veterinária - FMVZ

Forskolin effect on the cryosurvival of in vitro-produced bovine embryos in the presence or absence of fetal calf serum

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro embryos production after oocytes treatment with forskolin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CONTROL OF ADIPOSE-TISSUE LIPOLYSIS IN ECTOTHERM VERTEBRATES

Lipolytic activity of fish (Hoplias malabaricus), toad (Bufo paracnemis), and snake (Philodryas patagoniensis) adipose tissue was investigated in vivo and in vitro. Catecholamines or glucagon did not affect the release of free fatty acids (FFA) by incubated fish and toad adipose tissue. Catecholamines also failed to activate snake adipose tissue lipolysis, which even decreased in the presence of epinephrine. However, glucagon stimulated both the lipolytic activity of reptilian tissue in vitro and the mobilization of FFA to plasma when administered to snakes in vivo. The release of FFA from incubated fish, amphibian, and reptilian adipose tissue increased markedly in the presence of cAMP or xanthine derivatives, inhibitors of phosphodiesterase. Forskolin or fluoride, activators of specific components of the adenylate cyclase system, strongly stimulated toad adipose tissue lipolysis. The data suggest that adipocyte triacylglycerol lipase of ectotherm vertebrates is activated by a cAMP-mediated phosphorylation and that the organization of the membrane-bound adenylate cyclase system is similar to that of mammals.

Vitrificação de embriões bovinos produzidos in vivo e in vitro após lipólise química

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Angiotensin II AT(1) receptor mutants expressed in CHO cells caused morphological change and inhibition of cell growth

To assess the importance of the leucine residues in positions 262 and 265 of the angiotensin AT, receptor for signaling pathways and receptor expression and regulation, we compared the properties of CHO cells transfected with the wild type or the L262D or L265D receptor point mutants. It was found that the two mutants significantly increased the basal intracellular cyclic AMP (cAMP) formation in an agonist-independent mode. The morphology transformation of CHO cells was correlated with the increased cAMP formation, since forskolin, a direct activator of adenylate cyclase mimicked this effect on WT-expressing CHO cells. DNA synthesis was found to be inhibited in these cell lines, indicating that cAMP may also have determined the inhibitory effect on cell growth, in addition to the cell transformation from a tumorigenic to a non-tumorigenic phenotype. However a role for an increased Ca2(+) influx induced by the mutants in non-stimulated cells cannot be ruled out since this ion also was shown to cause transformed cells to regain the morphology and growth regulation. (c) 2005 Elsevier B.V. All rights reserved.

Caracterização fitoquímica e ensaios biológicos de Coleus blumei Benth

Coleus blumei Benth (Lamiaceae), popularly known in Brazil as heart-hurt or coleus-of-Java is an ornamental plant widely used due to the color of its leaves. Several species of the genus Coleus present compounds with antioxidant, antimicrobial and allopathic activities due to the presence of chemicals such coleonol, forskolin and rosmarinic acid. Therefore, this study aimed to carry out phytochemical study and biological tests to evaluate the antibacterial, antioxidant and allopathic activities of the 70% ethanol extract and its fractions ethyl acetate, dichloromethane and end aqueous fraction leaf of Coleus blumei Benth. The plant extract was prepared by turbolisis from the powder of dried leaves, as a solvent for extraction using 70% ethanol. The ethanol extract was fractionated with solvents dichloromethane and ethyl acetate. The phytochemical study identified the presence of saponins, free anthraquinones, flavonoids and anthocyanidins. In evaluating the antibacterial dichloromethane fraction showed activity against all microorganisms tested both in agar diffusion test and microdilution test. The 70% ethanol extract showed activity against the micro-organisms S. aureus and S. epidermidis in agar diffusion test and against all microorganisms tested in microdilution test. The ethyl acetate fraction showed activity against the micro-organism S. aureus in the agar diffusion test and against all microorganisms tested in microdilution test. The end aqueous fraction showed no activity against any micro-organism tested. In the test of evaluation activity allopathic dichloromethane fraction showed greater inhibition of seed germination and growth of tomato (Lycopersicon esculentum Mill), followed by 70% ethanolic extract, the ethyl acetate fraction and the end aqueous fraction. In testing the antioxidant activity with DPPH ethyl acetate fraction showed higher antioxidant activity followed... (Complete abstract click electronic access below)

Otimização do meio de transporte de oócitos bovinos destinados à produção in vitro de embriões

Pós-graduação em Medicina Veterinária - FCAV

Interação entre as vias de sinalização de receptores serotoninérgicos e Β-adrenérgicos em artéria femoral de ratos

Fundamento: A doença coronária tem sido amplamente estudada em pesquisas cardiovasculares. No entanto, pacientes com doença arterial periférica (DAP) têm piores resultados em comparação àqueles com doença arterial coronariana. Portanto, os estudos farmacológicos com artéria femoral são altamente relevantes para a melhor compreensão das respostas clínicas e fisiopatológicas da DAP. Objetivo: Avaliar as propriedades farmacológicas dos agentes contráteis e relaxantes na artéria femoral de ratos. Métodos: As curvas de resposta de concentração à fenilefrina contrátil (FC) e à serotonina (5-HT) e os agentes relaxantes isoproterenol (ISO) e forskolina foram obtidos na artéria femoral de ratos isolada. Para as respostas ao relaxamento, os tecidos foram contraídos com FC ou 5-HT. Resultados: A potência de classificação na artéria femoral foi de 5-HT > FC para as respostas contráteis. Em tecidos contraídos com 5-HT, as respostas de relaxamento ao isoproterenol foram praticamente abolidas em comparação aos tecidos contraídos com FC. A forskolina, um estimulante da adenilil ciclase, restaurou parcialmente a resposta de relaxamento ao ISO em tecidos contraídos com 5-HT. Conclusão: Ocorre uma interação entre as vias de sinalização dos receptores β-adrenérgicos e serotoninérgicos na artéria femoral. Além disso, esta pesquisa fornece um novo modelo para estudar as vias de sinalização serotoninérgicas em condições normais e patológicas que podem ajudar a compreender os resultados clínicos na DAP.