Showing papers in "Acta Physiologica Hungarica in 1990"

Specific tension of human elbow flexor muscles.

Abstract: Human muscle has a specific tension that is similar to that of other mammalian skeletal muscle. Further, it appears that with the appropriate application of present imaging capabilities, the specific tension of human muscle can be defined more precisely.

Dipeptidyl peptidase IV (DP IV) and superoxide dismutase activity in thymus-derived lymphocytes: effects of inhibitory peptides and Zn2+ in vitro.

Abstract: DP IV and superoxide dismutase (SOD) activity in thymus-derived lymphocytes of rats was assayed in vitro. The DP IV activity was measured fluorimetrically by hydrolysis of Leu-Pro-AMC, and the SOD activity by the inhibition of autooxidation of L-adrenaline. In order of their competitive inhibitory potency the following peptides were tested against DP IV and SOD activity: Ile-Pro-Ile (diprotin A), Val-Pro-Leu (diprotin B), Ile-Pro, Leu-Pro, Val-Pro, Tyr-D--Ala-Ala-Pro, Phe-Pro, Tyr-Pro, Ala-Ala-Pro and Gly-Pro. The peptides, in the order of their potency against DP IV, were effective to inhibit the SOD activity in T lymphocytes. Zn2+ ions exerted an inhibition on both DP IV and SOD activity in a near equimolar concentration. The involvement of Zn2+ as well as the peptides liberated by hydrolysis of polypeptides in regulation of cell-mediated immune responses has been discussed.

Influence of acute physical exercise on glutathione and lipid peroxides in blood of rat and man.

Abstract: In rats physical exercise (30 min running on a treadmill) lowered total glutathione, oxidized glutathione and lipid peroxide concentration in blood. In man (young healthy male volunteers, moderate to excellent physical condition) running (30 min) did not influence these parameters. It is concluded that by normal life and psychophysical vigilance the moderate oxidative stress could be compensated.

Effect of testosterone on adrenal corticosteroidogenesis in lithium treated male rats.

Abstract: Lithium chloride at a dose of 200 micrograms/100 g body weight/day given for 21 days caused a significant increase in adrenal weight, adrenal 5-ene-3 beta-hydroxysteroid dehydrogenase (5-ene-3 beta-HSD) activity along with elevation in serum level of corticosterone on the 22nd day in the rat. Administration of testosterone for the last 14 days to lithium treated rats caused a significant decrease in adrenal weight, adrenal 5-ene-3 beta-HSD activity and serum level of corticosterone in comparison to lithium treated animals.

Long-term effects of a single cadmium chloride injection on the ovulation, ovarian progesterone and estradiol-17 beta secretion in rats.

Abstract: On the day of dioestrus II rats were given 5, 10 or 15 mg/kg of cadmium chloride (CdCl2), or 1, 0 ml/kg of 0.9% NaCl solution. Then ovarian cycle was checked daily for a period of 12 cycle length. On the day of oestrus or expected oestrus in the 13th cycle the animals were anaesthetized with pentobarbital and cannulas were inserted in one of the femoral arteries and veins and in one of the utero-ovarian veins. Five-minute blood fractions were collected for 40 minutes and following the first blood samples 10 IU of hCG were injected iv. Ovarian venous outflow and blood pressure were continuously recorded. From the blood fractions progesterone (P) and oestradiol-17 beta (E2) were determined with RIA and the P and E2 secretion rates of ovary were calculated. Ovaries were excised and oviducts were flushed for counting oocytes. CdCl2 shortly after its administration induced a (dose-dependent) anoestrous period which turned into regular or irregular cycles depending on the dose. Part (28-32%) of the oestrous animals (14% that of the controls) remained unovulatory, when ovulation occurred normal number of ova was found. None of the doses of CdCl2 has influenced the blood pressure of animals and blood flow of the ovary. The basal secretion rate of P and E2 was not changed in the ovary compared to the controls. The hCG induced rise of P secretion, however, in the animals treated with 5 and 10 mg/kg bw CdCl2 was diminished and delayed, while in the animals treated with the 15 mg/kg Cd dose a complete lack of response was observed.

Spectra of the voluntary first cough sounds.

Abstract: The voluntary cough sounds recorded according to Korpas and Sadlonova-Korpasova were sampled at a frequency of 20.000Hz and spectra of six consecutive windows of 50ms were estimated. To digitize signals an autotrigger mode was used. The subjects were healthy volunteers as well as patients with chronic bronchitis, asthma, bronchial carcinoma (growing intraluminarly in the 1st or in the 2nd or in the 3rd order bronchi), emphysema, laryngeal nerve paralyzis or laryngotomy. The duration of averaged cough sounds of patients was longer than that of healthy volunteers. The mean power of the spectra in the successive windows showed different patterns in the same group. In the third window of healthy volunteers (0.10 s-0.15 s) a high modulus broad bandwidth (between 1-2 kHz) spectrum was found which was considered as a bronchial "flute", and was probably related to the lowest resistance as well as to the velocity of airflow of cough manoeuvre. This pattern appeared with a delay and/or it was changed in the diseased groups compared to the healthy volunteers. Due to this delay, the spectra of the fifth window (0.20 s-0.25 s) showed somewhat higher harmonics (400-800 Hz) in the patients with chronic obstructive pulmonary diseases (COPD), carcinoma and laryngeal nerve paralyzis than in healthy volunteers. In emphysematous patients in the first (0.00-0.05 s), in the third (0.10-0.15 s) and in the fifth (0.20-0.25 s) windows the fundamental frequency was low (156-176 Hz) compared to that of the other groups. The paralyzed vocal cords functioning as an added resistance to the expiratory effort caused a phase-shift in the cough patterns, similarly to that seen in COPD patients. Due to the cannula, the spectra of patients having laryngotomy had a lot of high harmonics. They also had peaks nearly identical to that of bronchitic patients because they suffered from serious chronic bronchitis. It was found that by examination the cough spectra of series of voluntary cough sound signals it was possible to distinguish healthy volunteers from patients. This examination would therefore be useful for screening of bronchial diseases.

Effects of space flight on bone formation and resorption.

Abstract: Samples of femurs and tibiae of male Wistar rats subjected to a 13 day space-flight on the biosatellite Cosmos 1887--were investigated and compared with vivarium and synchronous controls or immobilized rats, using histological and histomorphometric methods. 1. After flight in the metaphysis of bones the density and volume of the spongious trabeculae diminished significantly indicated by the Sv and Vv histomorphometric values and histological data comparing to the controls. In the diaphysis, the density of trabeculae decreased too. 2. In the flight group significant suppression of bone formation was determined by histological and histomorphometric (decrease of the OS, OB and OBI values) methods. 3. In the flight group according to the histological pictures the signs of bone resorption (increase of Hoswship's lacunae, osteoclastic activity, structural rarefication of spongious and cortical bones, osteon disintegration, osteocytic osteolysis) were revealed, which was substantiated by the histomorphometric results (increase of osteoclastic index: OCI). 4. Significant differences between flight and immobilized groups were not determined, except the osteoid value, which was increased in the case of immobilization. 5. Some histomorphometric values related to bone formation of synchronous control group showed close relationship rather to the flight group than to the vivarium control group.

Effects of two bioflavonoids on certain cellular immune reactions in vitro

Abstract: Oxidative and autoaggressive immune processes are supposed to be involved in the pathogenesis of certain chronic liver diseases. In this study the effects of two naturally occurring antioxidant flavonoids, (+)cyanidanol-3 and silymarin, were determined on T and active T cell percentages, antigen-dependent (ADCC), lectin-dependent (LDCC) and natural (NK) cell mediated cytotoxicity and on lectin induced blast transformation of lymphocytes from healthy subjects and patients with chronic alcoholic liver disease in vitro. We observed no effects on T and active T cell percentages and on ADCC activity. Both drugs decreased LDCC activities of patients and lectin-induced lymphoblast transformation of controls and patients, (+)cyanidanol slightly and silymarin significantly decreased NK activities of controls and patients. These suppressive effects could partly be explained by the free radical scavenger and lipoxigenase inhibitor activity of the drugs and support the promising role of bioflavonoids in the treatment of chronic liver diseases.

Effect of different vegetable oils on arrhythmias induced by myocardial ischemia in hypercholesterolemic rats.

Abstract: Rats treated neonatally or at four weeks of age with dexamethasone on a single occasion showed a considerable decrease in thymic glucocorticoid reception. It appears that hormonal imprinting can take place in the cells of the cytogenic organs not only perinatally, but also later, owing to the undifferentiated (differentiating) state of the forming cells.

Effect of restriction in daily feeding periods on reproduction in the female rat.

Abstract: Effects of restriction in daily feeding periods (2, 4, 8 and 12 hrs) imposed in 21 days old rats for 9 weeks were studied on the food intake, body growth, onset of puberty, reproductive cyclicity and ovarian functions. Control rats were feeding for 24 hrs ad lib. Though the restriction in feeding periods had no effect on the daily food intake but body growth was significantly reduced. Restricted feeding for 2, 4 and 8 hrs daily resulted in the delay in the onset of puberty, inhibition of oestrous cyclicity, reduction in ovarian weights, reduced growth, increased atresia of antral follicles and cessation of ovulation. The rats fed for 12 hrs daily, though weighed less but exhibited all the above mentioned reproductive functions similar to those of controls. The results have revealed that the restriction in feeding time induces nutritional deficiency, causing delay in sexual maturation and inhibition of ovarian functions.

Anticariogenic effect of fluoridated milk and water in rats

Abstract: The aim of the study was to get further experimental data on the anticariogenic effect of sodium fluoride (NaF) when administered in milk or water. Thirty six weanling Osborne-Mendel rats were divided into two experimental groups (A, B) of 12 rats each and two control groups (C, D) of six rats each. During the experimental period of four weeks all animals were superinfected with Strep. mutans (NCTC 10449), kept in an automatic feeding machine and given a cariogenic diet (MIT 301). Group A received sodium fluoride (NaF) in water (15 ppm) and group B in ultra high temperature treated milk. Groups C and D respectively received plain milk and distilled water. Group A did not show significantly lower caries reduction compared with the control groups. Group B had significantly the lowest caries scores compared with all other groups. Scores in group C (plain milk) were lower than those in groups D (plain water). The results suggest that the anticariogenic effect of NaF is more pronounced when the vehicle is milk instead of water.

Potential role of SH groups in the radiosensitivity of adenylate cyclase.

Abstract: The role of oxidation of SH groups in the activity of adenylate cyclase and in radiosensitivity of the enzyme was investigated. Adenylate cyclase activity was measured in purified membrane preparation of 19 day old chicken embryo brains. N-ethyl-maleimide (NEM) and lead-acetate were used as SH inhibitors. Gamma irradiation was carried out with 60-Co source. NEM inhibition of adenylate cyclase was dose dependent and 50 per cent inhibition was observed at 40-50 microM NEM. Activity of adenylate cyclase was elevated at lower concentrations of lead-acetate (10 nM-100 microM) and was inhibited at higher concentrations (above 100 microM). The presence of 40 microM NEM did not alter the shape of lead acetate saturation curve of adenylate cyclase. Gamma irradiation in the dose range of 100-800 Gy elevated the adenylate cyclase activity measured in the presence of 5 mM NaF but did not alter the basal activity. Gamma irradiation did not have significant effect on NEM saturation of adenylate cyclase, while it altered slightly the lead acetate saturation curve.

Effect of short-term spaceflight on the contractile properties of rat skeletal muscles with different functions.

Abstract: In the biosatellites "Cosmos-1514" and "Cosmos-1667" rats were exposed to weightlessness in the space for either 5 or 7 days. The contractile properties of the soleus, extensor digitorum longus (EDL), brachialis, plantar, gastrocnemius and triceps (caput mediale) muscles were studied after return to earth. The muscles of animals living freely (vivarium group) and animals kept under conditions identical to those on the biosatellite (synchronous group) served as controls. The myofibrils were preserved by glycerol treatment. The ATP-Ca+(+)-induced isometric tension as well as the speed of contraction were registered, through a signal transformer, on a potentiometric recorder. The experimental results are concomitantly recorded numerically and graphically on a Citizen 1200 printer and analyzed with a Commodore 128D computer. During the short-term spaceflight the greatest weight loss and decrease of contractile power was seen in the slow soleus muscle, i.e. weightlessness and immobilization led to the degeneration and weakening of mainly the tonic muscle fibres. Nevertheless after the short-term spaceflight, even with the present improved and sophisticated methods, the authors were unable to demonstrate, changes indicating muscle transformation which had been previously seen in rats exposed to weightlessness for 18.5 days.

The effect of various monoamine oxidase (MAO) inhibitors on the response of blood pressure of rats and cats to tyramine.

Abstract: The "cheese effect" is the clinically most important side effect of structurally different MAO inhibitors. It occurs mainly as a result of the interaction of MAO inhibitor with tyramine in foodstuffs. Anaesthetised rats and cats were used in order to investigate and compare the influence of the effect of tyramine by selective MAO type-B inhibitors with that produced by non-selective and A-selective MAO inhibitors on the one hand, and on the other hand, different MAO-B inhibitors with (-)deprenyl. (-)Deprenyl was the only one which inhibited the effect of tyramine in the experimental animals used, while other MAO inhibitors potentiated the tyramine effect. Therefore this study indicates that not only non-selective and A-selective inhibitors potentiate the effect of tyramine but selective inhibitors of B-type MAO as well. The inhibition of tyramine uptake by (-)deprenyl is a remarkable exception from the rule.

Pharmacological and electrophysiological analysis of nicotine induced apnoea in the cat.

Abstract: Intravenous nicotine (20-60 micrograms/kg) produced an initial brief apnoea followed by hyperventilation in anaesthetized cats. The apneic response to nicotine remained uneffected by atropine, by phentolamine or propranolol. Hexamethonium and guanethedine sulphate antagonized the apneic response. In bilateral vagotomized cats, nicotine failed to produce respiratory apnoea. Veratridine and phenyldiguanide produced apnoea similar to that produced by nicotine within 2-3 sec. administered intraartrially. Nicotine failed to stimulate pulmonary stretch receptors as did veratridine in artificially ventilated cats. The alpha and gamma motoneurone activity of inspiratory and expiratory muscles and the phrenic efferent activity were inhibited during apnoea. These inhibitions were absent in vagotomized cats. In conclusion, these results suggest that the nicotine induced apneic response is mediated through pulmonary vagal afferents, probably through J-receptors, which in turn inhibit the motoneurone activity involving the respiratory muscles.

Neuroparalytic keratitis and capsaicin.

Abstract: Subcutaneous injection of 50 mg/kg capsaicin to newborn rats resulted in a marked decrease of heat pain sensitivity and neurogenic inflammation. There was, however, no significant difference between capsaicin-pretreated and control rats in the severity of neuroparalytic keratitis after surgical deafferentation of the eye. Retrobulbar injection of 100 microliters of 0.5% capsaicin produced keratitis-like corneal changes. These changes were not prevented by previous pretreatment with a total subcutaneous dose of 200 mg/kg capsaicin. The findings indicate that corneal changes after deafferentation are not due to excessive release of substance P and other neuropeptides from the degenerating afferent fibres.

The role of histamine release in shock.

Abstract: More than 80 years after its discovery and nearly 70 years after its first being implicated in the mechanism of shock, the precise role of histamine (H) in the pathophysiology of the condition remains to be determined. The prevailing view over the decades has been that H is a noxious mediator contributing to the fatal outcome of shock. An adequate assessment of its role has long been hampered by the lack of a sufficiently sensitive and specific method for the measurement of H and by deficiencies of design in many studies. We now know that H is released in all types of shock. In low-output, high-resistance states, as in hypovolemic and cardiogenic shock, its effect (contrary to previous notions) appears to be beneficial, probably through the inhibition of excessive vasoconstriction and through a positive inotropic effect. In endotoxin shock the results are conflicting, but seem to indicate that H is not a lethal factor. In human septic shock, patients who died had higher H levels. The role of H release in the various forms of shock, both experimental and human, clearly needs an adequate, critical reevaluation, in carefully designed and executed studies using satisfactory methodology.

Effects of non-steroidal antiphlogistics on mouse ear oedema induced with dithranol.

Abstract: Mouse ear oedema induced with dithranol in mice of the CFLP strain was decreased significantly, in a dose-dependent manner, by the oral administration of the following non-steroids 60 minutes before induction of the oedema: piroxicam, proquazone, azapropazone, nifluminic acid and phenylbutazone. An approximately 50% inhibitory effect could be attained with the following doses: 3.3 mg/kg piroxicam, 5 mg/kg proquazone, 5 mg/kg azapropazone, and 1 mg/kg nifluminic acid. Administration of the largest dose (30 mg/kg) of phenylbutazone, used for comparison, resulted in an oedema decrease of 41%.

Effect of emetine on the plasma cell population of chicken's gland of Harder.

Abstract: The emetine effectively abolished the plasma cell population in the chicken's gland of Harder by day 3 of treatment. The plasma cell content regenerated by day 5 following emetine injection, possibly from a metabolically inactive, resting B cell population which was resistant to the emetine treatment. By day 7 extracellular substance in a very large quantity appeared among the plasma cells and epithelial cells which might represent a hyperactive plasma cell secretion. The changes in the circulating antibodies measured by hemagglutination well-correlated with the plasma cell content in the gland of Harder. The gland of Harder (GH) is an accessory lacrimal gland. Its main function is to lubricate the nictitating membrane and keep the surface of the eyeball wet. The presence and regulatory function of cAMP dependent histone kinase was showed. Since it has been published that in chicken the interstitium of this gland contains a proper amount of plasma cells, this observation called the attention of many investigators to study the role of GH in the immune response. The B cell maturation in the chicken GH has been studied. The surface marker studies have proved that beside the B cells the gland contains functionally adequate number of T cell which exert stimulatory effect on B cells to promote their transformation to plasma cells. In addition to T and B cells small number of macrophages also occur. In the 9 H the number of plasma cells is age dependent. At hatch only a few plasma cells occur in the interstitium of the gland but by 3 weeks of age they become predominant. Different isotypes of immunoglobulins are secreted by these plasma cells.

Regulation of femoral vascular resistance by adenine nucleotides via endothelial and smooth muscle receptors.

Abstract: It is well established that adenosine (ADO) and adenine nucleotides are potent vasodilators, but their role in local blood flow control is still under debate. Recent findings on contribution of vascular endothelium to the vasomotor regulation pointed out this problem. In the present study the effects of adenine nucleotides were investigated in vivo on the femoral arterial flow (FAF) and femoral vascular resistance (FVR). Selective suppression of the endothelium mediated dilation was achieved by gossypol (35 mumol/l). On intact hindlimbs ADO (4 mmol/l) and ATP (0.5 mmol/l) elicited 3.5-fold increase of FAF, in average. Resistance decreased by 6.24 +/- 0.58 and 7.23 +/- 1.12 peripheral resistance units (PRU100), respectively. After gossypol, ATP-induced dilation was either significantly suppressed (resistance-decrease was 3.70 +/- 0.58 PRU100; p less than 0.02 vs control) or turned to strong constriction (FAF decreased by 50%). ADO-induced dilation remained unchanged. These results, in agreement with in vitro data, suggest that adenosine directly relaxes the vascular smooth muscle of resistance vessels via P1-purinoceptors, while ATP-induced vasomotion is composed of a dilator effect mediated by endothelial P2y-receptors, and a direct constrictor effect on the vascular smooth muscle via P2x-purinoceptors.

Effect of CH-103, a beta adrenergic receptor antagonist on the activity of Ca2+, Mg2+-ATPase in rat cardiac sarcolemma

Abstract: Insulin imprinting given to the unicellular Tetrahymena considerably increases the uptake and intracellular storage of amino acids even many generations after the actual contact with the hormone. On the other hand, both the first and the second contacts with insulin increase the rate of the excretion of the stored amino acids. On the basis of the results obtained it seems to be possible that both protein synthesis and exocytosis of the Tetrahymena change as an effect of imprinting, either in general or specifically due to the formation of new hormone receptors.

Improvement of learning ability in mice and rats with the root extract of dinh lang (Policias fruticosum L.).

Abstract: The effect of Dinh lang root extract (DLRE) on the learning ability of mice and rats was studied. The learning performance in groups of rats belonging to different age-cohorts (4-6 months, 16-18 months and 22-24 months) was studied in the shuttle-box and the age-related decline in the acquisition of a conditioned avoidance response (CAR) was established. Using the passive avoidance test also in mice, an age-related decay in performance, was detected. DLRE treatment 10 mg/kg daily for 3-4 weeks restored the lost ability of 22-24 months old rats to develop CAR, the same treatment significantly improved the performance of young mice and improved retention in both 5-months old and 19-20 months old groups of mice.

Direct effects of lithium chloride on testicular delta 5-3 beta and 17 beta-hydroxysteroid dehydrogenase activities in the rat--in vitro study.

Abstract: Testicular delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenase (delta 5-3 beta- and 17 beta-HSD) activities of rat are inhibited in vitro by a wide range of lithium concentration. The inhibitory effects of lithium are evident at a concentration of 2.5 mM which is easily achieved during the treatment of acute manic patients with lithium. This suggests that lithium exerts a direct inhibitory effect on testicular hydroxysteroid dehydrogenase activities.

Permanence of the cell-to-cell transmission of insulin induced hormonal imprinting.

Abstract: When insulin-treated (imprinted) Chang liver cell cultures were mixed with cultures which did not receive insulin treatment the information of imprinting was transmitted to the cultures which were not in direct contact with insulin. The ability of the cells to transmit imprinting was long lasting and could be detected even after four weeks, when it was nearly of the same degree as at the first measurement. Difference was found between the binding capacity of the receptors of the plasma membrane and those of the nuclear membrane.