RESUMEN
We reported previously that intrauterine asphyxia acutely affects the rat hippocampus. For this reason, the early effects of this injury were studied in the cerebral cortex, immediately after hysterectomy (acute condition) or following a recovery period at normoxia (recovery condition). Lactacidemia and glycemia were determined, as well as glycogen levels in the muscle, liver and cortex. Cortical tissue was also used to assay the ATP levels and glutamate uptake. Asphyxiated pups exhibited bluish coloring, loss of movement, sporadic gasping and hypertonia. However, the appearance of the controls and asphyxiated pups was similar at the end of the recovery period. Lactacidemia and glycemia were significantly increased by asphyxia in both the acute and recovery conditions. Concerning muscle and hepatic glycogen, the control group showed significantly higher levels than the asphyxic group in the acute condition and when compared with groups of the recovery period. In the recovery condition, the control and asphyxic groups showed similar glycogen levels. However, in the cortex, the control groups showed significantly higher glycogen levels than the asphyxic group, in both the acute and recovery conditions. In the cortical tissue, asphyxia reduced ATP levels by 70 % in the acute condition, but these levels increased significantly in asphyxic pups after the recovery period. Asphyxia did not affect glutamate transport in the cortex of both groups. Our results suggest that the cortex uses different energy resources to restore ATP after an asphyxia episode followed by a reperfusion period. This strategy could sustain the activity of essential energy-dependent mechanisms.
Asunto(s)
Animales Recién Nacidos/metabolismo , Asfixia/metabolismo , Corteza Cerebral/metabolismo , Ácido 3-Hidroxibutírico/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Glucemia/análisis , Femenino , Ácido Láctico/sangre , Ratas , Ratas WistarRESUMEN
The present study assesses the effects of starvation and refeeding on 1-[(14)C]-methyl aminoisobutyric acid ((14)C-MeAIB) uptake, (14)C-total lipids, (14)CO(2) production from (14)C-glycine, (14)C-protein synthesis from (14)C-leucine and Na(+)-K(+)-ATPase activity in jaw muscle of Neohelice granulata previously maintained on a carbohydrate-rich (HC) or high-protein (HP) diet. In N. granulata the metabolic adjustments during starvation and refeeding use different pathways according to the composition of the diet previously offered to the crabs. During starvation, (14)CO(2) production from (14)C-glycine, and (14)C-protein synthesis from (14)C-leucine were reduced in HC-fed crabs. In crabs maintained on the HP or HC diet, (14)C-total lipid synthesis increased after 15 days of starvation. In crabs fed HP diet, (14)C-MeAIB uptake and Na(+)-K(+)-ATPase activity decreased in refeeding state. In crabs refeeding HC diet, (14)C-MeAIB uptake and (14)CO(2) production decreased during the refeeding. In contrast, the (14)C-protein synthesis increased after 120h of refeeding. In both dietary groups, (14)C-total lipid synthesis increased during refeeding. Changes in the carbon amino acid flux between different metabolic pathways in muscle are among the strategies used by this crab to face starvation and refeeding. Protein or carbohydrate levels in the diet administered to this crab modulate the carbon flux between the different metabolic pathways.