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Biomedical subjects

H Bräunlich

Publications and source records attributed to H Bräunlich.

At least 19 recordsLinked to original sources
PubMed1992

Liver function after bilateral nephrectomy.

Consequences of bilateral nephrectomy (NX) for liver functions and for hepatic excretion of various endogenous substances were characterized in rats 24 h after NX. Plasma concentrations of urea, creatinine, fibrinogen, and glutathione increased significantly after NX, whereas the concentrations of total protein, albumin, and lipids decreased. The hepatic excretion of urea, creatinine, phospholipids, cholesterol, and aldosterone significantly increased in uremia, and excretions of protein and glutathione diminished. Active biliary transport can be diminished after NX by the effects of uremic toxins on the liver cells or by the competition phenomena between endogenous substances, which are normally excreted in urine, at the hepatocellular level. Reduced glutathione content and increased lipid peroxidation in hepatocytes have been found. Changes in lipid and protein metabolism after NX can be proved.

Albumins↗
PubMed1992

Stimulation of renal tubular transport of p-aminohippurate in rats of different ages by treatment with adrenocortical steroids.

Treatment with prednisolone or dexamethasone is followed by an increase in renal excretion of p-aminohippurate (PAH) and in accumulation of PAH in renal cortical slices, particularly in 5- and 10-day-old rats with immature kidney function. Treatment with triamcinolone is effective both in immature and in 55-day-old rats. There is no stimulation of PAH transport after treatment with mineralocorticoids (desoxycorticosterone, aldosterone).

Adrenal Cortex Hormones↗
PubMed1992

Synergistic effect of triiodothyronine and dexamethasone on renal tubular transport of p-aminohippurate in rats of different ages.

Postnatal maturation of the renal tubular transport of p-aminohippurate (PAH) was verified in rats both in diuresis experiand on renal cortical slices in vitro. Following treatment with various doses of triiodothyronine (T3) or dexamethasone (3 days, once a day), the increase in renal tubular transport of PAH was more distinct in young rats with immature kidney function. The synergistic effects of simultaneous treatment with both hormones indicate differences between T3 and dexamethasone in the modulation of cellular function.

Aging↗
PubMed1992

[The renal effects of dopamine therapy in premature infants in the first week of life].

It is known that Dopamine therapy induces loss of water and sodium on the first or second days of life. On the other hand, no studies have been published on renal function under long-term therapy. In our study we could prove an altered excretion of water and sodium as well as fractional sodium excretion in preterm infants who received dopamine for at least the first week of life. Conclusions for clinical practice are drawn.

Creatinine↗
PubMed1992

[The occurrence of aluminum-containing lysosomes in the kidney of experimentally treated rats].

Aluminium was detected by electron spectroscopic imaging and electron energy loss spectra in the lysosomes of all cell types of the nephron in rats treated with aluminium chloride after 5/6 nephrectomy. The lysosomes of kidney cells of untreated rats did not demonstrate any detectable amounts of aluminium. Electron energy loss spectra showed the regular occurrence of iron (and also other elements) in the lysosomes of both groups of rats.

Aluminum↗
PubMed1991

Nephrotoxic effects of diethylene glycol (DEG) in rats.

Diethylene glycol (DEG) is a widely used substance with various risks of intoxication. In adult rats influences of DEG on functional parameters are characterized, indicating early signs of nephrotoxicity. A dose dependent proteinuria, an oliguric effect, an increased excretion of free hydrogen ions and a compensated impairment of renal tubular transport processes can be stated (0.25, 0.5 and 0.75 ml DEG/100 g b.m. i.p.). Following a single dose of 0.5 ml DEG/100 g b.m. i.p. the maximally expressed nephrotoxic effect is measurable 4 to 8 days after administration.

Animals↗
PubMed1991

Influence of vasoactive substances on uremic bleeding in rats.

Bleeding time is prolonged following resection of kidney tissue as well as after ureteral occlusion. Bilateral nephrectomy raises bleeding time from 17 to 67 min, and blood loss can be increased from 2 to 12 microliters/min. Plasmatic coagulation factors remain unchanged in uremic rats. There is no influence of various surgical interventions producing uremia on function of thrombocytes. In rats with intact kidney function and following bilateral nephrectomy a diminution of bleeding time is demonstrable after administration of histamine or captopril. Shortening of bleeding time by the antifibrinolytic substance p-aminomethylbenzoic acid seems to indicate an increased fibrinolytic activity in uremic rats.

4-Aminobenzoic Acid↗
PubMed1991

Relation between renal and hepatic excretion of drugs. XIV. Elimination of ioglycamic acid after nephrectomy, bile duct ligation, and after treatment with hormones or xenobiotics in young and adult rats.

Ioglycamic acid (IGA) is effectively eliminated in young and adult rats via urine and bile. After administration of low doses hepatic excretion dominates whereas following high supply renal elimination surpasses biliary excretion. Hepatic transport of IGA is active, indicated by the occurrence of a transport maximum in vivo and by a distinct accumulation of this drug within liver slices in vitro. Renal removal of IGA is preferentially caused by glomerular filtration. A tubular reabsorption obviously does not occur because forced diuresis (mannitol, furosemide) does not increase renal excretion of this substance. As calculated from our clearance data and as a result of accumulation experiments in vitro on renal cortical slices the active tubular secretion of this organic anion can be excluded. In principle there are no qualitative changes in IGA elimination between the 20th and 55th day of life, but active hepatic transport of the drug is significantly lower in young, immature rats. After bile duct ligation, renal excretion of IGA increases distinctly in both age groups, whereas in adult rats bilateral nephrectomy (NX) is followed by a significant decrease in its hepatic excretion in dependence on time after kidney removal. In young rats NX is without consequences on hepatic excretion of IGA. It is possible to stimulate renal and/or hepatic excretion of IGA by repeated administration of T3, dexamethasone, or phenobarbital. The effect of stimulation is different in kidney and liver and depends on age, too.

Animals↗
PubMed1991

Chromate nephrotoxicity in developing rats. Significance of Cr(VI) reduction in rat kidney tissue.

Chromate reduction was studied in 9000 x g supernatant of renal tissue. It was shown that GSH plays an important role. Additionally, heat-sensitive factor(s) seem to be involved. Age differences in chromate nephrotoxicity parallel differences in chromate reduction in vitro. The lower reductive activity of young rats can be raised to adult values by GSH-addition. Fasting reduces GSH concentration, as well as chromate nephrotoxicity, in vivo.

Aging↗
PubMed1991

Relation between renal and hepatic excretion of drugs: XV. Organ distribution and transport of the new antiarrhythmic drug Bonnecor in kidney and liver of rats.

Following administration of various doses of 14C-labeled Bonnecor (0.15 to 0.6 mg/100 g b.wt. i.v.) renal excretion of 14C-radioactivity dominates and the total rate of excretion both via kidney and liver reaches 60% during 6 h clearance experiment, independent of the administered dose. Otherwise nearly the same concentration of 14C-radioactivity can be measured in kidney and liver tissue. An alpha- und beta-slope of disappearance from the tissue seems to exist. At different times after administration of Bonnecor (0 to 15 h) the concentrations in kidney and liver tissue are distinctly higher compared with plasma concentrations. In vitro experiments on tissue slices confirm a nearly identical degree of accumulation of 14C-radioactivity in liver and kidney. In renal cortical slices the high degree of accumulation depends on active tubular transport processes. Comparing accumulation in liver slices under aerobic and anaerobic conditions a preferential passive uptake of Bonnecor can be demonstrated. Efflux kinetics in slices from liver and kidney cortex is in accordance with this interpretation.

Animals↗
PubMed1991

[Electron microscopic evidence of aluminum in lysosomes of kidney cells by electron energy loss spectroscopy].

Aluminium effects have increasing attention in long term dialysis of kidney patients and in a number of cerebral diseases. At present, however, there are still many open points concerning its localization and actions in the cell. If using electron spectroscopic imaging (ESI), aluminium could be directly demonstrated in the lysosomes of the kidney cells of uraemic rats experimentally loaded with aluminium. These findings were corroborated by means of electron energy loss spectroscopy (EELS).

Aluminum↗
PubMed1990

[Possibilities for increasing the elimination rate of Bonnecor].

Bonnecor is excreted in rats both via urine (3/4) and bile (1/4). It was the aim of this study to find out suitable methods for detoxication of a poisoning with this antiarrhytmic drug. In vivo methods intended to enhance the renal excretion of Bonnecor (forced diuresis, changes in urinary pH-values, peritoneal dialysis) are not qualified for therapeutically relevant increase of Bonnecor elimination. Relating to this Bonnecor is quite comparable with other antiarrhythmic drugs or dibenzazepine derivatives. The hemoperfusion can be recommended for the therapy of a Bonnecor overdosage as a propping up of symptomatic methods of intensive care, which are precendentally indicated. Therefore the therapy of a Bonnecor poisoning seems to be more promising compared to intoxications with other antiarrhythmics. Among the adsorbents tested, the resin Wofatit UH91 is most suitable to remove Bonnecor from the organism. If hemoperfusion equipments are not available, hemodialysis can also be used for acceleration of Bonnecor elimination, although its effectivity is only one third of that of hemoperfusion.

Animals↗
PubMed1990

Influence of metyrapone and phenobarbital on sodium dichromate nephrotoxicity in developing rats.

After the administration of equal doses of sodium dichromate, chromium concentrations in the kidney were lower in young than in adult rats. To test the age-dependent sensitivity to the nephrotoxicity of dichromate, young and adult rats were given doses to achieve identical chromium concentrations in the kidney. At equal renal concentrations, young rats had less functional and morphological damage than adult rats. As phenobarbital treatment in young rats enhanced the symptoms of nephrotoxicity and metyrapone treatment in adult rats decreased the symptoms of nephrotoxicity, age-dependent differences in chromate nephrotoxicity may be linked to an increase in the enzymatic reduction of Cr(VI) with age.

Aging↗
PubMed1990

Role of glutathione in vanadate reduction in young and mature rats: evidence for direct participation of glutathione in vanadate inactivation.

The influence of renal glutathione content, modulated by the glutathione synthesis inhibitor buthionine sulphoximine or by glutathione infusion, on the polyuric and natriuretic effects of i.v. administered vanadate was investigated in 20- and 55-day-old rats. The modulation of renal glutathione content led to significant changes in urine volume and sodium excretion, independently of age. A decrease in the renal glutathione level led to intensification and prolongation of the diuretic effects of vanadate in 55-day-old animals. Treatment with glutathione abolished and treatment with buthionine sulphoximine increased the polyuric effect of vanadate. These observations indicate a role for renal glutathione in vanadate inactivation. Age-dependent differences in the polyuric and natriuretic effectiveness of vanadate are caused by differences in renal glutathione content during maturation of the kidney.

Aging↗
PubMed1990

Triiodothyronine (T3) increases cisplatin nephrotoxicity in young and adult rats.

The influence of pretreatment with triiodothyronine (T3) on cisplatin (CP)-induced nephrotoxicity was investigated in 10- and 55-day-old rats. Triiodothyronine pretreatment enhanced CP proteinuria in young and adult rats, and increased blood urea nitrogen concentration in 55-day-old rats. As T3 decreased Pt concentrations in renal tissue, the enhanced nephrotoxicity of CP by T3 must have another mechanism. Enhanced CP nephrotoxicity is discussed in connection with an increase of glutathione concentration obtained in renal tissue as a consequence of T3 pretreatment.

Aging↗
PubMed1990

Age dependent differences in the functional and morphological impairment of kidney following cisplatin administration.

In adult rats the clearance of inulin, urinary p-aminohippurate (PAH) excretion, TmPAH, as well as PAH accumulation in renal cortical slices were decreased 48-72 h following 0.6 mg cisplatin/100 g body mass (b.m.). Morphological investigations showed changes preferentially in proximal tubules. Reduced inulin clearance is discussed to be rather the consequence of inulin back leak in destroyed tubules than of a real decrease in glomerular function. The ultrastructure of glomeruli, distal tubules, and collecting ducts was not affected by cisplatin (CP) in 10- and 55-day-old rats. In 10-day-old rats, inulin clearance and urinary PAH excretion remained unaffected by CP, whereas TmPAH and PAH accumulation in vitro were significantly decreased following CP. Most significant ultrastructural changes occurring in mitochondria are discussed to cause decreased PAH accumulation following CP. The high portion of PAH filtered in young rats masked this impairment of active PAH secretion. Lower nephrotoxicity in young rats seems to be caused by low state of a differentiation of cell structure and transport function.

Age Factors↗