Acta physiologica Academiae Scientiarum Hungaricae最新文献

To determine the prostaglandin dependent and independent effects of bradykinin in the kidney, bradykinin (0.05 microgram/min/kg body weight) was infused into the left renal artery during inhibition of prostaglandin synthesis by indomethacin. Indomethacin, 0.1 mg/min/kg body weight i.v. produced a marked fall in urine output and sodium excretion in anaesthetized dogs. Renal vascular resistance increased and renal blood flow (RBFdir) decreased by 30%. When during the i.v. infusion of indomethacin bradykinin was infused into the left renal artery, RBFdir, urine flow and sodium excretion increased to the control values in the left kidney while remained lower in the right kidney. The results suggest that bradykinin increases renal blood flow by an action which does not require the mediation of prostaglandins. A decrease in renal blood flow, which was a constant feature during i.v. indomethacin infusion, is probably responsible for the decrease in urine flow and sodium excretion. The failure of indomethacin to inhibit the natriuretic and diuretic effects of bradykinin suggests that the prostaglandins are not important determinants of these responses.

The effect of 1 to 6-week limb immobilization by plaster fixation and the resulting skeletal muscle inactivity-atrophy was studied by analysing isotachophoretically the ATP, ADP, AMP, CrP, NAD+ and Pi content of the slow-oxidative soleus, and the fast-glycolytic gastrocnemius muscle of the rabbit. ATP and CrP levels were higher in the glycolytic while NAD+ content was higher in the oxidative skeletal muscle under normal conditions. Energy homeostasis of the muscles disturbed during the first week of immobilization, and subsequently it is adapted to the inactivity by reaching a new steady state at lower energy levels. This new level as characterized by the high energy phosphate content shows no significant difference between the two muscle types.

Interstitial fluid pressure was measured by Guyton's capsular method in the subcutaneous tissue of rats after a single DOC i.p. injection. Regardless of the dose of DOC, the pressure-time curve showed three phases: latency, decrease and recovery. The maximum drop in pressure and the recovery time were dose-dependent. Maximum decrease in interstitial fluid pressure after 0.25; 0.50; 0.75; 1.00 mg/100 g body wt of DOC was 3.2; 7.1; 9.2 and 10.6 mmHg, respectively. It was found that the recorded pressure response is not exclusively caused by Starling forces. A correlation was found between the pressure decrease and the extracellular potassium loss. The role of potassium in the DOC-induced pressure response was verified by administration of the specific potassium ionophore, valinomycin. Due to the effect of valinomycin, potassium ion transport and, as a consequence, the interstitial pressure response, were accelerated.

A total of 58 MZ and 41 DZ Hungarian adult like-sexed twin pairs were studied for the presence of betanin in urine (called betaninuria) after the ingestion of a standardized beetroot juice. By means of a semi-quantitative technique, betaninuria values of all test persons were determined. Several mathematical models were tested to find a probability distribution fitting well to the empirical data. The hereditary character of the intensity of betaninuria cannot definitely be accepted although some circumstances pointed to the effect of genetic factors on the phenomenon.

Hypotonic haemolysis of newborn and adult human red blood cells (RBC) is more intensive at 4 than at 37 degrees C. Newborn RBC are more resistant to the decrease of temperature than adult RBC. Transition temperature of the RBC membrane can well be determined by illustrating osmotic haemolysis as a function of temperature. This parameter characterizes well the microviscosity of the membrane. The inclination point of Arrhenius curves representing transition temperature occurred always at 25 degrees C both in the case of adult and newborn RBC. The similarity of the transition temperature indicates the similarity of membrane microviscosity of newborn and adult human RBC.

In the experiments presented here, serum samples were collected both from psoriatic (PS) (n = 8) and non-psoriatic (NPS) patients (n = 8) and were analyzed by the combination of fractional precipitation (80% ethanol, pH 2) and gel filtration techniques as well as by chemical methods. It was demonstrated that, in comparison to the non psoriatic samples, concentration of the free alfa-amino group bearing and the Lowry positive components as well as total carbohydrate content was significantly elevated in the acidic ethanol soluble serum fraction of psoriatic samples. In psoriasis, the quantity of serum components with UV light absorbing capability at 206 nm, and with a molecular mass between 0.3 and 5.0 KD (estimated by chromatographic criteria) also was elevated in one of the fractions obtained by Sephadex SG-25 chromatography. Results presented in this paper indicate, that psoriasis is accompanied by changes in quality and in quantity of middle size molecular weight serum components with chemical properties suggesting their peptide--and/or glycopeptide-like character.

Sulfhydryl substances (cysteine, glutathione, cysteamine and BAL) provide protection against experimental gastric ulcer induced by indomethacin while being ulcerogenous in stress-ulcer. Experimental data indicate the necessity to distinguish between "real" and "occasional" cytoprotective drugs.

In the rabbit hindleg lymph and tissue fluid were collected before and during close intraarterial infusions of histamine (2.5 and 10 micrograms/min) or bradykinin (0.4 microgram/min). Protein concentration was higher in the tissue fluid than in the lymph. During the 2h of the experiment in the control animals protein concentration increased in the lymph and decreased in the tissue fluid. Lymph flow decreased in the controls and it was not significantly influenced by histamine but was in the majority of animals (14 of 20) grossly augmented by bradykinin. Lymphatic protein and LDH fluxes were increased both by bradykinin and histamine. In animals where the vasoactive agents failed to alter lymph flow LDH concentration in the lymph increased significantly without comparable changes in the tissue fluid. On the other hand, in experiments where lymph flow was increased lymphatic LDH activity decreased but the activity in tissue fluid remained unchanged. It is concluded that the interstitial fluid is composed of two compartments. Only the perivascular compartment of tissue fluid is drained directly by the lymph vessels and lymph is essentially a recent microvascular filtrate. The second compartment of the interstitial fluid in rinsing the cells and connective tissue fibres, it is parallelly coupled and in exchange with the perivascular compartment.