996 resultados para Rat Week
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
To test the hypothesis that the trophic action of angiotensin II on the adrenal zona glomerulosa may allow a sustained stimulation of aldosterone by ACTH by preventing the morphological changes of the zona glomerulosa cells into zona fasciculata-like elements we investigated the effects in rats of a 6-day treatment with ACTH (100 micrograms/kg/day) alone or combined with angiotensin II (300 ng/kg/day) on corticosterone and aldosterone production and adrenal morphology. The responsiveness of both steroids to an acute ACTH dose was also studied on the last day of long-term treatment. Morphologic data showed that prolonged ACTH treatment stimulated the growth of zona glomerulosa cells, though it transformed the tubulo-lamellar cristae of mitochondria into a homogeneous population of vesicles. Angiotensin II furthered the trophic effects of ACTH but prevented the mitochondrial transformation. Despite its ability to conserve the well differentiated aspect of the zona glomerulosa cells, the administration of angiotensin II was unable to prevent the fall in the secretion of aldosterone caused by chronic ACTH treatment and its subsequent unresponsiveness to ACTH stimulation.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
The role of cytochrome P450 in the metabolism of dextromethorphan, amitriptyline, midazolam, S-mephenytoin, citalopram, fluoxetine and sertraline was investigated in rat and human brain microsomes. Depending on the parameters, the limit of quantification using gas chromatography-mass spectrometry methods was between 1.6 and 20 pmol per incubation, which generally contained 1500 microg protein. Amitriptyline was shown to be demethylated to nortriptyline by both rat and human microsomes. Inhibition studies using ketoconazole, furafylline, sulfaphenazole, omeprazole and quinidine suggested that CYP3A4 is the isoform responsible for this reaction whereas CYP1A2, CYP2C9, CYP2C19 and CYP2D6 do not seem to be involved. This result was confirmed by using a monoclonal antibody against CYP3A4. Dextromethorphan was metabolized to dextrorphan in rat brain microsomes and was inhibited by quinidine and by a polyclonal antibody against CYP2D6. Only the addition of exogenous reductase allowed the measurement of this activity in human brain microsomes. Metabolites of the other substrates could not be detected, possibly due to an insufficiently sensitive method. It is concluded that cytochrome P450 activity in the brain is very low, but that psychotropic drugs could undergo a local cerebral metabolism which could have pharmacological and/or toxicological consequences.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
Resumo:
Record of the Fatalities for Motor Vehicle Accidents in Iowa per week.
