Romanian journal of physiology : physiological sciences最新文献

Spectrophotometric assays have been used to determine FA concentration in tissue homogenates from various organs (liver, kidneys, brain, spleen) in white rats; these studies were undertaken to test the age--and organ--dependent variations of FA concentrations in tissue homogenates. The results showed a marked decrease of FA concentration in the adult group of rats when related to the young group, and in the aged group when compared to the adults respectively. Analysing the determined values of folates in tissue homogenates of various organs (in rats belonging to the same group of age), the highest concentration has been found in the liver homogenate, followed in decreasing order by kidneys and to a much greater distance, by the brain and spleen.

The possible participation of NO in the pain modulation and stress analgesia was studied in Wistar adult rats. Cerebral citruline as a stoichiometric coproduct of NO from L-arginine increased from the mean value 5.6 +/- 0.4 nM/mg.Pt. to 8.9 +/- 0.5 nM/mg.Pt. in acute immobilization stress. Intraperitoneal administration of L-arginine caused only in high doses (50 mg/kg body weight) a small transient decrease of tail-flick latencies to the thermoalgesic stimulus, without significant changes of the stress analgesia induced by the restraint stress. In the pretreated animals with L-NAME a progressive increase of latency time was obtained and the increased latencies induced by acute immobilization appeared significantly potentiated. These results offer new indirect evidence in favour of the modulatory role of NO in the thermoalgesic sensitivity and stress induced analgesia.

The clinical and experimental investigations of alcoholic liver disease, have proved that hepatocytes injury is associated with immunologic abnormalities, which can be one of the sources of these injuries. The acetaldehyde, the main ethanol metabolite modify liver cytosolic proteins and form new antigens. Thus acetaldehyde induces the synthesis of auto-antibodies. Some hypotheses maintain the autoimmune pathogenesis of these diseases. Research was carried out on some patient groups admitted in the alcohol addiction department of the Neurology and Psychiatry hospital "Professor Gh. Marinescu". We have investigated the alcohol depending individuals with various degrees of hepatic injuries. Four groups have been studied: the control group, the alcohol depending patients without liver disease, the patients with alcoholic hepatitis, the group with alcoholic cirrhosis. In order to investigate the immunologic response the research has been carried on, along the following lines: serum immunoglobulins level, serum C3 level, serum protein C reactive level by using IDR, serum circulating immune complexes by Hakova method, auto-antibodies (antinuclear AAN, antimitochondria AM and antismoothmuscle ASM) by using indirect immunofluorescence, T lymphocytes by E rosetting and lymphocytes by direct immuno-fluorescence. Clinical and experimental study of the alcoholic liver has shown that destruction of hepatocytes is accompanied by several immunological events.

The use of visual evoked potentials in the detection of optic chiasma syndrome of tumoral etiology has been controversial in the literature. In our study the pattern visual evoked potentials (PVEP) were recorded in 22 healthy free volunteers and in 32 patients with optic chiasma syndrome (OCS) produced by tumors of the hypothalamic-pituitary area, mainly pituitary adenomas with suprasellar extension, proved by CT scan. The PVEP were recorded bilateral after monocular photic stimulation of each atropinized eye, in parallel with a complete ophthalmologic exam consisting in visual field, visual acuity and optic fundus. The main results showed that the latencies P100 recorded bilateral were correlated (p < 0.01) with the types of visual field deficiency, in each hemifield. The changes in P100 latency are more sensitive than the evolution of visual field deficiency by campimetry. The same correlation was observed between the "W" form of P wave with the visual field defect. A significant decrease (p < 0.05) of the amplitude of P100 was observed only if the visual acuity was less than 1/2. It is suggested that the PVEP is a reliable index of diagnosis and evolution for the optic chiasma syndrome aside the usual ophthalmologic exam.

The role of the thymus in maintenance of the basal phagocytosis of blood neutrophils and eliciting the phagocytic response, induced by i.v. Escherichia coli, was studied in 9 NMRI thymectomized and in 12 control mice. Thymectomy depresses the percentage of phagocyting neutrophils from 70.91 +/- 0.9 (mean +/- SEM) in controls, to 61.49 +/- 2.33 in the thymectomized rats. Phagocytic activity, as assessed by the number of bacteria engulfed by 100 neutrophils, was also lower in thymectomized mice (114.42 +/- 7.52) than in controls (163.71 +/- 4.53). A phagocytic response to i.v. Escherichia coli could nevertheless be noted in thymectomized mice, their phagocytic activity rising from the basal activity of 114.42 +/- 7.52 to 142.19 +/- 5.40 three hours after injection of Escherichia coli, while in control animals this activity rose from 163.71 +/- 4.53 to 216.46 +/- 12.91. These results may, at least partially, explain the recurrent infections and the septicemia occurring in children with Down's syndrome. It is suggested that the thymus, as an endocrine organ, may be involved in maintaining the basal phagocytic activity of blood neutrophils, while the phagocytic response is modulated by extrathymic mechanisms.

Using aortic rings from male Wistar rats, we studied the influence of nitric oxide (NO) on the vascular reactivity to angiotensins. The inhibition of NO-synthesis by L-NAME produced on both intact and desendothelised rings an augmentation of vascular reactivity to angiotensins. NO inhibition did not affect the blocking effects of Saralasin to angiotensins vasoconstriction, suggesting that NO cannot act directly on angiotensin II receptor. Nifedipin inhibited the stimulatory effect of L-NAME on angiotensins vasoconstriction. The results of our study provide functional evidence that NO production can interfere with vascular RAS at two levels: 1. by modulating the activity of Ang II-forming enzymes; 2. at intracellular level, by modulating the concentration of calcium. Also, our results suggest the existence of an alternative pathway on Ang II formation, that become more evident with removal of endothelium.

This review outlines in brief the research performed in Romania on several directions of the stress topics, as follows: historical background, theoretical developments and critical approaches to Selye's theory, experimental research, methodological aspects, occupational stress, stress and immunity, clinical studies, including studies on post-traumatic stress disorder. Five books on stress published by Romanian authors are mentioned and the importance of a psychoneuro-endocrinological insight is underlined.

The purpose of the study has been to observe the influence of an increased dietary sodium intake over cerebral excitability in rats. Research was conducted on two lots of animals: the first lot (PSA) was maintained under the influence of an increased intake of sodium given in the form of physiologic solution, instead of water. That regimen was started during gestation and continued after birth for another 12-14 months before the rats were sacrified. The second lot was given distilled water (DWA) in an identical manner. In other respects, the diet was similar for both lots We compared the following parameters: a) Electrophysiological (electrocorticogram); b) Hydroelectrolytic balance; c) Sodium concentration capacity of the kidney; d) Mineral-corticoid response; e) Motor and motivational behaviour. The data we obtained point to: 1. A shifting of the ECG frequency spectrum towards higher frequency in rats that consumed NaCl in excess. 2. PSA consume significantly more saline solution than DWA, therefore liquid consumption is also greater. Renal elimination of water, Na and K is significantly greater is PSA compared to DWA. Moreover, DWA conserve sodium while PSA conserve water, the respective values being different in a considerable degree in the two lots. 3. The value of the (urinary Na/urinary K) ratio is double in PSA compared to DWA, pointing to a decrease in mineral-corticoid secretion. 5. The animals that have chronically consumed a hypersaline diet show a significantly greater motor agitation compared to the DWA. When free to choose from among physiological solution, water and glucose solution, PSA show no preference for sodium: this points to the absence of obtained motivation for the saline solution The data support the idea that a chronically increased content of dietary NaCl stimulates cerebral excitability.

The purpose of this research has been to assess the role of lipidic peroxides, the involvement of the superoxide radical and of sulfhydrylic groups in isoproterenol-induced myocardium hypertrophy in rats. The results of our investigations point to increased values by 25% of plasma lipidic peroxides and in the myocardium and to a decrease of sulfhydrylic groups and of superoxide dismutase in the groups with myocardial hypertrophy, 15% and 10% respectively, compared to the controls. The comparative analysis of the data enabled us to infer the consequences of lipidic peroxides and of free radicals presence in excess and to assess the protector role of fosfobion- an energising compound-against the structural lesions of the myocyte.