RESUMO
[3H]Palmitic acid and [14C]arachidonic acid were injected together into the cerebral ventricle of 4-month and 24-month-old rats. At different time intervals from the injection, the distribution of these fatty acids in the lipids from different brain areas was examined. The fatty acids were rapidly incorporated into the lipids through different mechanisms. The time-specific activity relationship indicate that the utilization of the fatty acid differs according to the different areas and aging decreases the utilization of both the fatty acids. The decline of arachidonic acid incorporation into phospholipids is particularly evident, indicating that aging affects mainly the utilization of polyunsaturated fatty acids.
Assuntos
Ácidos Araquidônicos/metabolismo , Encéfalo/metabolismo , Ácidos Palmíticos/metabolismo , Fosfolipídeos/biossíntese , Envelhecimento , Animais , Ácidos Araquidônicos/administração & dosagem , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Cromatografia Líquida de Alta Pressão , Corpo Estriado/metabolismo , Hipocampo/metabolismo , Injeções Intraventriculares , Masculino , Ácidos Palmíticos/administração & dosagem , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
The activities of phospholipase A1 and A2 were tested in mitochondria and microsomes from different cerebral areas of both 4 month and 24 month old rats, after 30 days i.p. treatment with ox Brain Cortex Phosphatidyl Serine (BC-PS). In the brain areas from control animals a rather great decline in its ability to hydrolize the fatty acids of the main phosphoglycerides was found. Taking into account only the effect of treatment with BC-PS on the modification of phospholipase activities caused by aging, we found that the treatment was able to balance the enzymatic functions altered by aging in several of the area examined. The importance of this result on the lipidic metabolism of the aging brain is also discussed.
Assuntos
Encéfalo/enzimologia , Fosfatidilserinas/farmacologia , Fosfolipases A/metabolismo , Fosfolipases/metabolismo , Envelhecimento , Animais , Masculino , Fosfolipases A1 , Ratos , Ratos Endogâmicos , Frações Subcelulares/enzimologiaRESUMO
An age-related decrease of calmodulin content was detected in the striatum, cerebral cortex and cerebellum of 3-, 22- and 30-month-old rats. This age-related decrease of calmodulin level occurred both in the supernatant and in the pellet fraction of high speed centrifuged tissues. However, the rates of age-dependent calmodulin loss in the pellet and supernatant fraction were differentiated according to the cerebral region considered, suggesting a different brain area sensitivity to the aging process.
Assuntos
Envelhecimento , Proteínas de Ligação ao Cálcio/análise , Calmodulina/análise , Fatores Etários , Animais , Química Encefálica , Cerebelo/análise , Córtex Cerebral/análise , Corpo Estriado/análise , Ratos , Ratos EndogâmicosRESUMO
Recent advances indicate that cyclic nucleotides and perhaps certain adrenergic metabolites might be directly involved in contact-inhibition mechanisms and tumoral cell growth. CSF levels of 3'-5' cAMP, 3'-5' cGMP, HVA, and 5-HIAA were investigated in patients with supratentorial malignant gliomas, brain stem gliomas and posterior fossa medulloblastoma. cAMP levels were slightly decreased only in medulloblastomas, whereas no significant difference was detectable in patients with supratentorial gliomas. cGMP values turned out to be significantly higher, with a very peculiar increase in the most anaplastic neoplasms. Postoperative follow-up showed a gradual decrease of cGMP values, with progressive restoring of a normal cAMP/cGMP ratio. The possible correlation of these findings with CSF levels of HVA and 5-HIAA is discussed.