Effects of growth hormone on GFR and renal plasma flow in man.
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Glomerular Filtration Rate↗
Biomedical subjects
R Hirschberg
Publications and source records attributed to R Hirschberg.
Effect of long-term administration of 1,25-dihydroxyvitamin D3 and 1 alpha-hydroxyvitamin D3 on the calcium content of the aorta, heart and kidney of normal and uremic rats.
Studies in uremic rats were performed to see whether or not the long-term administration of therapeutical doses of 1,25-Dihydroxyvitamin D3 or 1 alpha-hydroxyvitamin D3 would induce histological changes in the aorta or increase the calcium content of the aorta or the heart. In contrast to observations of others, no effect of both vitamin D sterols could be observed on both investigated tissues. However, the remnant kidneys of the rats treated with both vitamin D compounds showed a significantly increased calcium content. According to these results one cannot exclude that the chronic application of active vitamin D metabolites has induced a calcium deposition in the remnant kidney. This finding deserves special attention, although we found, on the other hand, no evidence that an underlying arterial disease is aggravated by this therapy.
Animals↗
Effect of an acute protein load on the creatinine clearance in healthy vegetarians.
In normal man an acute protein load increases the glomerular filtration rate (GFR) significantly, which seems to represent a renal functional reserve. Healthy vegetarians are known to have a statistically reduced baseline GFR. We performed three creatinine clearance studies (24-h study design) on each of nine healthy vegetarian subjects. The first clearance was measured as baseline, the second one was done on day 2 after an oral protein load of 100 g vegetarian protein (1.2-2.0 g/kg body wt.), respectively, ingested within half an hour. The third clearance, serving as a control, was done on day 14. All subjects had their normal vegetarian meals during the study. All vegetarians had at all times a normal serum creatinine level. The mean baseline creatinine clearance was 65.4 +/- 33.3 ml/min. 1.73 m2. In five of nine vegetarians we found a significant increase of the creatinine clearance after the protein load of 66.0% (mean) and a decrease to the baseline values, respectively, when the control clearance was measured. The remaining four vegetarians did not increase their creatinine clearance immediately after the protein challenge and their control clearances were found to be significantly reduced (-40.2%) compared to the individual baseline.
Adult↗
Endotoxin-induced acute renal failure in mice. Effects of indomethacin and the thromboxane-synthetase antagonist UK 38.485.
Functional acute renal failure (ARF) was induced within 24 h following i.p. injection of 200 micrograms E. coli endotoxins (ET) into C3H/HeHan mice. Pre- and post-treatment with either UK 38.485, a selective thromboxane (TX)-synthetase inhibitor, or with the cyclo-oxigenase inhibitor, indomethacin (IM), does not prevent acute renal failure in these mice. Histologically, only very little fibrin degradation and few microthrombi are present 24 h later in the kidneys, so that disseminated intravascular coagulation (DIC) mechanisms cannot have caused the significant azotemia. Slight histological changes are accentuated in the UK 38.485-treated group. Only the indomethacin group has a significantly increased mortality as compared to all other groups. We conclude from our study that with low dosages of endotoxins functional ARF can be induced in mice without a circulatory shock and early mortality and that both UK 38.485 and IM are of little value in preventing it.
Acute Kidney Injury↗
Tubulin genes of the African trypanosome Trypanosoma brucei rhodesiense:nucleotide sequence of a 3.7-kb fragment containing genes for alpha and beta tubulins.
Most tubulin genes of the African trypanosome Trypanosoma rhodesiense are contained in 3.7-kb tandemly repeating units. One member of the 3.7-kb repeat family has been isolated from a T. rhodesiense genomic library, cloned, and sequenced. The 3646-bp fragment contains a complete alpha-tubulin gene and portions of two beta-tubulin genes. No introns are present. The genes are separated by 634- and 333-bp intergenic regions, which lack typical eukaryotic promoter and poly(A) signal sequences. However, both intergenic regions exhibit some structural similarity with sequences proposed to be involved in transcription termination and poly(A) addition in yeast. The 634-bp intergenic region shows homology to the "mini-exon" sequence associated with variable surface glycoprotein (VSG) and other trypanosome mRNAs. A comparable sequence is not found in the 333-bp intergenic region. T. rhodesiense alpha and beta-tubulins exhibit about 84-85% amino acid (aa) sequence homology with tubulins of mammals; the genes show about 74-75% nucleotide sequence homology. The alpha-tubulin contains 451 aa and the beta tubulin 442 aa; both have tyrosine as the C-terminal aa.
Amino Acid Sequence↗
Parathyroid hormone and 1,25-dihydroxyvitamin D3 affect the tissue concentrations of zinc in uremic rats.
The tissue concentration of zinc was studied in normal and uremic rats. Differences between the groups only reached significance when either parathyroid hormone or 1,25-dihydroxyvitamin D3 were administered. Uremic rats having obtained these compounds showed a significantly higher concentration of zinc in their liver, whereas their serum content of zinc was decreased.
Animals↗
Organ distribution of aluminium in uremic rats: influence of parathyroid hormone and 1,25-dihydroxyvitamin D3.
Investigations were performed in order to see whether or not the application of parathyroid hormone or 1,25-dihydroxyvitamin D3, or both might influence the organ distribution of orally and parentally administered aluminium in control and uremic rats. The data show that 1,25-dihydroxyvitamin D3, affects the organ uptake in a different way than parathyroid hormone. Whereas parathyroid hormone increased the aluminium concentration in the liver, 1,25-dihydroxyvitamin D3 enhanced the aluminium uptake in the heart and the muscle, on the other hand, simultaneous application of 1,25-dihydroxyvitamin D3 and parathyroid hormone decreased the aluminium content of the bone, liver and brain.
Aluminum↗
No rise in glomerular filtration rate after protein load in severe liver disease.
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Female↗
Effect of diets containing varying concentrations of essential fatty acids and triglycerides on renal function in uremic rats and NZB/NZW F1 mice.
Influences of essential fatty acids (EFA) and triglycerides as reasons for the progression of chronic renal failure are still in debate. We studied the outcome of four diets containing different concentrations of triglycerides and EFA in 5/6 nephrectomized rats and in NZB/W mice up to 45 weeks. The results showed no significant differences in the outcome of survival rate, proteinuria, urea, and creatinine levels as well as histological findings in the different groups of both animal models. We conclude that diets containing EFA up to C18:2 or being free of EFA or that triglyceride-enriched diets have no influence on the natural course of the renal disease in these both experimental models.
Animals↗
[Toxic shock syndrome. Pathogenesis, diagnosis, therapy].
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Animals↗
Digoxin-quinidine interaction in patients with renal failure.
Investigations were performed in order to study whether or not quinidine would exert similar effects on the serum digoxin concentration in patients with renal failure as in normal subjects. Fourteen out of fifteen patients showed a significant increase of the serum digoxin level after four days of quinidine application. This indicates, that the quinidine effect is not solely caused by a decrease of the renal digoxin clearance, although nine patients, not being hemodialysed, revealed a correlation between their creatinine clearance and the rise of the serum digoxin concentration after quinidine. As however, the patients on hemodialysis did not show higher digoxin levels than those treated conservatively, it is suggested that the degree of the uremic intoxication might be responsible for the observed correlation.
Acetyldigoxins↗
Effect of chlorpromazine on phototactic behavior in Chlamydomonas.
Chlorpromazine, an antipsychotic drug, causes a light intensity dependent reversal of phototaxis in the green alga Chlamydomonas reinhardi. At moderate light intensity, drug-treated cells swim away from the light (negative phototaxis) while untreated cells swim toward it (positive phototaxis). At low light, both treated and untreated cells exhibit normal positive phototactic responses. It appears that light and chlorpromazine may affect a common control system for phototaxis.
Chlamydomonas↗
Comparative investigations on the biokinetics of colloidal thorium, zirconium, and hafnium dioxides in animals.
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Animals↗
Chemoresponses of Chlamydomonas reinhardtii.
Cells of Chlamydomonas reinhardtii have been found to respond to chemicals in two ways: chemokinesis and chemotaxis. Several amino acids, fatty acids, and inorganic salts can stimulate these responses.
Amino Acids↗
Phototaxis mutants of Chlamydomonas reinhardtii.
A group of 31 mutants of Chlamydomonas reinhardtii with altered phototactic responses was isolated. Growth of all the mutants was normal and, with one exception, they had no gross morphological aberrations. One mutant produced supernumerary flagella. The mutants can be subdivided into five phenotypic classes on the basis of their abnormal responses: slow positive, no reponse, slow negative, fast negative, and variable. Random motility of the mutants was also characterized. About half were indistinguishable from wild type; the others exhibited "jerky" or "twirly" movements instead of relatively straight paths. These mutants can now be used for genetic and biochemical studies of the cellular basis of phototaxis.
Chlamydomonas↗
Studies on nuclear and mitochondrial DNA of Saccharomyces cerevisiae.
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Cell Nucleus↗
Phototaxis in Chlamydomonas reinhardtii.
Parameters which distinguish phototaxis from random motility in Chlamydomonas reinhardtii have been defined with quantitative assays. The phototactic responses in photosynthetic, mixotrophic, and heterotrophic cultures were highest during exponential growth and declined rapidly as the cultures entered stationary phase. In contrast, random motility was relatively constant throughout growth. Phototaxis and motility also differ in their sensitivity to azide and antimycin A. Both of these drugs inhibited phototaxis within 5 min, but motility was unaffected for at least 30 min. Phototaxis and motility have different ion requirements. Optimum motility was observed in the presence of either Ca(++) or Mg(++); phototaxis required Ca(++) and either K(+) or NH(4) (+). Photosynthesis is not required for phototaxis, since phototaxis was not inhibited by dichlorophenyldimethyl urea, and a mutant lacking chlorophyll was phototactic.
Antimetabolites↗
Oxidation of nicotinic acid by a Bacillus species: regulation of nicotinic acid and 6-hydroxynicotinic acid hydroxylases.
The first two enzymes employed by a Bacillus species for the dissimilation of nicotinic acid are coordinately induced. The inducer of the enzymes appears to be 6-hydroxynicotinic acid, the product of the first enzyme in the pathways. Synthesis of the enzymes is repressed by glucose when ammonium is present in the medium, but not when nicotinic acid is the sole nitrogen source. The possible significance of the coordinate induction and unusual repression is discussed.
Bacillus↗