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Stability of ascorbyl palmitate molecule in the rat brain

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Recent investigations have shown the ability of ascorbyl palmitate (AP), a bioactive, lipid-soluble ester of ascorbic acid (AA), to penetrate neural tissues. This study seeks to determine the occurrence of hydrolysis of AP molecule in brain tissue, which could rather point to the action of AA alone carried over the biological barrier and then released from the AP compound. The integrity of AP molecule was examined qualitatively in the rat brain by thin-layer-chromatography. AP was injected into an internal carotid artery in a dose of 75 mg per rat after tying off the common and external carotid arteries at the same side. The rats were sacrificed 15 min later, the brain tissue was extracted with chloroform/methanol and chromatographed. The AP bands plated from the samples ispilateral to the injection side strictly corresponded to the AP standard's location and were clearly separated from the AA standard with no overlap. The experiment showed that AP resists hydrolysis in the brain and thus the short-term biological effects of AP may be ascribed to the action of an intact ester molecule. The results may help elucidate the biological action of AP, a compound that increasingly attracts attention for biomedical use due to its antioxidant potential and ability to penetrate into the membrane signaling target sites.
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Oxygen breathing and ventilation

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We investigated the ventilatory response to normobaric poikilocapnic hyperoxia in healthy subjects. The study was carried out in 26 subjects of the mean age 26 ±0.9 (SE) years, who breathed pure oxygen through a two-way valVE for 10 min. The subjects were in the sitting position with a mouthpiece and nose clip attached. Ventilatory flow was recorded using a pneumotachograph and minute ventilation was calculated from the tidal and frequency components. The SaO2 and alveolar CO2 tension were continuously monitored. Ten of the same subjects constituted a control group in which room air was substituted for oxygen and the tests repeated in the same way at another occasion. We found that oxygen breathing caused a transient 8.4% decline in ventilation, whose nadir was 1 min after the introduction of oxygen. Thereafter, ventilation increased significantly aboVE the baseline value and showed a further rising tendency toward the end of the test. We conclude that acute oxygen treatment is unlikely to haVE a major inhibitory effect on the carotid body-dependent ventilatory driVE in normal subjects. The determinants of the hyperoxic ventilatory stimulation remain to be established in further studies.
Lymphocyte-induced angiogenesis (LIA), a vascular response was observed when allogenic immunocompetent lymphocytes of C3H/w mice infected with Trichinella spiralis were inoculated intradermally into irradiated BALB/c. It was shown that intestinal phase of T. spiralis infection stimulated mainly CD5 T cells dependent angiogenesis. The enhancement of angiogenesis did not occur in the early and late muscular phases of the infection. It is suggested, that changes in the intensity of angiogenesis may play a role in spreading of new-born larvae in the host.
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