Neonatal influence of monosodium glutamate on the somatometric parameters of rats.

The glutamate receptors are expressed in various cell types including bone and adipose cells. The effects of neonatal administration of monosodium glutamate (MSG) on the "programming" of somatometric parameters in Wistar rats during the period up to 14th week of life were estimated. The rats were treated subcutaneously with five doses of 4 mg/g MSG (10 microl/g body mass) during the first 10 postnatal days (group M). The control (group C) was treated in the same manner with normal saline solution. During three months, body mass, naso-anal length and tail length were measured in 14 days intervals, while femoral and tibial masses and lengths, and testicular mass were measured following sacrificing. The body mass at the end of this period in the M group of males was higher than the body mass in the group C. Reduction in relative bone length, body and tail lengths and the relative as well as absolute testicular mass were registered in MSG-treated rats. A significant reduction in somatometric parameters was registered only in female MSG-treated rats during period of sexual maturation compared to controls.

Protective effect of interferon-alpha on the DNA- and RNA-degrading pathway in anti-Fas-antibody induced apoptosis.

AIM: Fas membrane-associated polypeptide antigen is a receptor molecule responsible for apoptosis-mediated signals. In animal models of acute viral hepatitis, apoptosis of hepatocytes is mediated by Fas-death receptors; therefore, the aim of this study was to evaluate the effect of interferon (IFN)-alpha on apoptotic markers and nuclease activity against different coding and non-coding single and double stranded RNAs during Fas-induced liver apoptosis. METHODS: An in vivo experiment was performed with simultaneous administration of anti-Fas (CD95) antibodies and IFN-alpha, and an in vitro experiment was performed in hepatocyte cultures treated with anti-Fas antibodies and IFN-alpha. RESULTS: Detection of apoptosis using Annexin V-FITC/propidium iodide, Bcl-2 and Bax expression in hepatocyte cultures confirmed the appearance of early apoptotic events and progression toward late apoptosis after anti-Fas antibody treatment. IFN-alpha had a tendency to retard the apoptosis process in Fas-induced apoptosis by increasing the number of viable cells and decreasing the number of cells in late apoptosis, by increasing the percentage of Bcl-2 positive cells, by decreasing the percentage of Bax positive cells, and by decreasing the nuclease activity compared to the anti-Fas antibody treated group. Total DNA and RNA concentration was much reduced in the Fas group and DNA fragmentation assay provided evidence for increased DNA degradation. Enhanced nuclease activity against DNA, rRNA, poly(A), poly(C), poly(U), poly(I:C), and poly(A:U) was manifested in the anti-Fas antibody treated group, except for the inhibitory-bound alkaline RNase. CONCLUSIONS: The results demonstrate that the RNA-degrading pathway in Fas-induced apoptosis can accelerate the liberation of the latent enzyme from the inhibitor complex. IFN-alpha prevented enormous, Fas-ligand induced degradation of all the substrates used in this experimental study, most probably due to similarities in the signal transduction pathways. Investigations of death receptor-induced apoptosis may lead to novel treatment combinations for patients with acute or chronic liver diseases.

Curcumin attenuates Mancozeb-induced toxicity in rat thymocytes through mitochondrial survival pathway.

The widely used fungicide Mancozeb (Man) has been shown to cause genotoxic effects in rodents and toxicological manifestations in different cells, mainly by altering the antioxidant defense in cells. On the other hand, curcumin (Cur), a natural phenolic compound, is thought to possess anti-inflammatory and antioxidant properties. Here, we investigated the possible protective role of Cur on Man-induced toxicity in rat thymocytes and potential mechanism involved. Rat thymocytes were treated with Man(0.01 µg/ml) and/or increasing Cur(0.3, 1, 3 µM) concentrations and levels of cell viability, apoptosis, mitochondrial membrane potential (MMP),Bcl-2, Bax protein expression, caspase-3 and -9 activity and p38 MAPK signaling involvement were examined. Cells treated with Man displayed increased cell toxicity, hypodiploid cells, caspase-3 and -9 activity, Bax protein expression, followed with decreased MMP and Bcl-2 protein expression. Inhibition of p38 MAPK signaling pathway markedly reduced apoptosis rate and caspase-3 activity in thymocytes exposed to Man. Application of increasing Cur (1, 3 µM) concentrations resulted with significantly reduced cytotoxicity, apoptosis, caspase-3, -9 activity, Bax protein expression, together with increased MMP and Bcl-2 protein expression in rat thymocytes. These result suggest that certain Cur concentrations may mediate Man-induced rat thymocytes toxicity through mitochondrial survival pathway, which may be useful in preventing possible secondary immunological consequences induced by Man.

Effect of monosodium glutamate on oxidative stress and apoptosis in rat thymus.

It has been demonstrated that administration of high concentrations of monosodium glutamate (MSG), induce oxidative stress in different organs, but not in thymus. In the present study we examined the role of oxidative stress in MSG-induced thymocyte apoptosis. MSG was administrated intraperitoneally (4 mg/g of body weight) for six consecutive days. Animals were sacrificed at 1st, 7th, and 15th day after last MSG dose. MSG administration to animals significantly increased apoptotic rate of thymocytes (P < 0.01), together with significant increase of malondialdehyde (MDA) level (P < 0.001) and xanthine oxidase (XO) activity (P < 0.01), in time dependent manner. Catalase activity, during examination period, was significantly decreased (0 < 0.01). Obtained results showed that MSG treatment induced oxidative stress in thymus, which may have an important role in thymocyte apoptosis induced by MSG.

Formant structure of the voice during the intensive acute hypoxia.

The influence of intensive acute hypoxia on the frequency-amplitude formant vocal O characteristics was investigated in this study. Examinees were exposed to the simulated altitudes of 5,500 m and 6,700 m in climabaro chamber and resolved Lotig's test in the conditions of normoxia, i.e. pronounced the three-digit numbers beginning from 900, but in reversed order. Frequency and intensity values of vocal O (F1, F2, F3 and F4), extracted from the context of the pronunciation of the word eight (osam in Serbian), were measured by spectral speech signal analysis. Changes in frequency values and the intensity of the formants were examined. The obtained results showed that there were no significant changes of the formant frequencies in hypoxia condition compared to normoxia. Though, significant changes of formant's intensities were found compared to normoxia on the cited altitudes. The rise of formants intensities was found at the altitude of 5,500 m. Hypoxia at the altitude of 6,700 m caused the significant fall of the intensities in the initial period, compared to normoxia. The prolonged hypoxia exposure caused the rise of the formant intensities compared to the altitude of 5,500 m. In may be concluded that, due to different altitudes, hypoxia causes different effects on the formants structure changes, compared to normoxia.