PubMed Health⌕ Search

Biomedical subjects

D Pawlowska

Publications and source records attributed to D Pawlowska.

8 recordsLinked to original sources

The decrease of superoxide dismutase activity and depletion of sulfhydryl compounds in ethanol-induced liver injury.

There appears to be increasing evidence that ethanol toxicity may be associated with an increased production of reactive oxygen intermediates. In rats we studied the effect of 4 weeks of ethanol ingestion on the liver cytosolic defense system against active oxygen species. Compared with the control rats, the ethanol-fed animals had a significantly higher liver malondialdehyde content and significantly lower reduced glutathione level. Moreover, ethanol feeding resulted in a decrease of superoxide dismutase and catalase activities while glutathione peroxidase activity was only slightly diminished. Thus, prolonged ethanol administration profoundly modified the hepatic status of the enzymatic defense system leading to lipid peroxidation that may disrupt vital functions of liver cells.

Animals↗

The effect of Heparegen and D-penicillamine on the activity of some ammonia metabolizing enzymes in liver and brain of rats intoxicated with ethanol.

This paper reports data on the effect of two drugs: Heparegen (thiazalidine-4-carboxylic acid) and D-penicillamine on the blood ammonia concentration and on some ammonia metabolizing enzymes in liver and brain of rats intoxicated with ethanol. It seems, that both drugs decrease ammonia concentration and simultaneously elevate liver and brain glutamine synthetase activity. The effect of D-penicillamine on the nitrogen metabolism in the damaged liver appears to be more favorable than that of Heparegen.

Alcoholic Intoxication↗

Ethanol decreases the level of sulfhydryl compounds in red blood cells and changes their hematological pattern in rats.

The level of sulfhydryl compounds in red blood cells (RBCs) and plasma and some haematological parameters were investigated in rats treated with ethanol for 4 weeks (daily dose of 6g/kg, 30% w/v, p.o.). After ethanol ingestion, the significant decrease of non-protein - SH groups were observed in RBCs and plasma. In treated rats, the mean corpuscular haemoglobin concentration (MCHC) was decreased and the mean corpuscular volume (MCV) was increased. There is a positive correlation between these two parameters and decreased content of sulfohydryl groups in RBCs.

Animals↗

Prostaglandin blockade blunts the natriuresis of elevated renal interstitial hydrostatic pressure.

Previous studies have shown that renal interstitial volume expansion (RIVE) increases renal interstitial hydrostatic pressure and urinary sodium excretion. In the present study we investigated whether blockade of prostaglandin synthesis inhibits the increase in fractional sodium excretion induced by RIVE. Expansion of the renal interstitial volume was achieved by injecting 50 microliters of 2.5% albumin solution into a polyethylene matrix chronically implanted in the left kidney. Fractional sodium excretion (FENa), renal interstitial hydrostatic pressure (PI), and urinary prostaglandin excretion (UPGE2) were measured before and after RIVE in eight control, seven meclofenamate-treated, and eight indomethacin-treated rats. RIVE in the control animals resulted in significant increases in PI (delta + 4.2 +/- 0.8 mmHg), in FENa (delta + 1.02 +/- 0.27%), and in UPGE2 (% delta + 150 +/- 38%) without significant changes in glomerular filtration rate. Inhibition of prostaglandin synthesis with meclofenamate or indomethacin attenuated the natriuretic response and blocked the increase in UPGE2 associated with RIVE. In summary, direct increases in renal interstitial hydrostatic pressure increase UPGE2 and urinary sodium excretion. This natriuretic response is markedly diminished by inhibition of prostaglandin synthesis. These studies suggest that prostaglandin synthesis may have an important role in mediating the natriuretic effect of increased renal interstitial hydrostatic pressure during renal interstitial volume expansion.

Animals↗

Effect of direct increases in renal interstitial hydrostatic pressure on sodium excretion.

This study examined the effect of increases in renal interstitial hydrostatic pressure (PI) on sodium excretion (UNaV) utilizing a direct technique for increasing renal interstitial volume. PI was increased by renal interstitial volume expansion (RIVE) via injection of 50 microliters of a 2% albumin in saline solution into the renal interstitium through a chronically implanted interstitial catheter. RIVE resulted in a stable increase in PI (4.6 +/- 0.4 to 9.4 +/- 0.8 mmHg) that was sustained over a 30- to 40-min period without significant changes in renal blood flow or glomerular filtration rate. Increases in PI were associated with significant increases in urine flow (13.8 +/- 3.4 to 31.7 +/- 5.0 microliters/min) and UNaV (2.3 +/- 0.6 to 6.2 +/- 1.1 micro eq/min) and fractional excretion of Na (2.6 +/- 0.8 to 6.9 +/- 1.5%). To determine the importance of albumin in maintaining an elevated PI, the effects of renal interstitial injections of saline were compared with albumin in saline solution. Injection of 50 microliters of saline into the renal interstitium had no sustained effect on PI. Injection of 2% albumin in saline solution in the same group of rats resulted in significant elevations in PI and UNaV. These data indicate that direct increases in PI via renal interstitial volume expansion result in significant increases in UNaV, thus supporting a role for PI in controlling UNaV.

Animals↗

Effects of adenosine infusion into renal interstitium on renal hemodynamics.

This study was designed to investigate the hemodynamic effects of exogenous adenosine in the interstitium of the rat kidney. Adenosine or its analogues were infused into the renal interstitium by means of chronically implanted capsules. Infusion of adenosine (bolus 0.5 mumol plus 0.1 mumol/min) decreased glomerular filtration rate (GFR) from 0.81 +/- 0.06 (mean +/- SE) to 0.37 +/- 0.06 ml/min while having no effect on renal blood flow (RBF). The metabolically stable analogue, 2-chloradenosine (2-ClAdo), (bolus 10 nmol plus 2 nmol/min) decreased GFR from 0.73 +/- 0.07 to 0.21 +/- 0.06 ml/min. Interstitial infusion of theophylline, an adenosine receptor antagonist, completely abolished the effects of adenosine and 2-ClAdo on GFR. The distribution of adenosine, when infused into the renal interstitium, was determined using radiolabeled 5'-(N-ethyl)-carboxamidoadenosine (NECA), a metabolically stable adenosine agonist. After continuous infusion, [3H]NECA was distributed throughout the kidney. The effects of NECA to reduce GFR were similar to those of adenosine and 2-ClAdo. We conclude that increased levels of adenosine in the renal interstitium markedly decrease GFR without affecting RBF in steady-state conditions. The marked effects of adenosine agonists during their infusion into the renal interstitium and the complete blockade of these effects by theophylline suggest an extracellular action of adenosine.

2-Chloroadenosine↗

The effect of immunostimulatory drugs on sulfhydryl compounds in plasma, liver and brain after ethanol-induced liver injury in rats.

Sulfhydryl compounds in plasma, liver and brain of rats treated with two immunostimulant drugs, isoprinosine and levamisole, after alcoholic liver injury have been investigated. After use of both drugs for 6 days we found partially beneficial effect on the SH-groups in plasma and liver. No changes in nonprotein SH compounds were observed in rat brain after treatment with isoprinosine, levamisole or ethanol. Furthermore, levamisole shortens the time necessary for the return of AlAT activity to normal value.

Animals↗