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H Hackbarth

Publications and source records attributed to H Hackbarth.

29 records · Page 2Linked to original sources
PubMed1982

Genetic analysis of renal function in mice. 2. Strain differences in clearances of sodium, potassium, osmolar and free water, and their correlations with body and kidney weight.

There was greater then 4-fold strain differences in the clearances of sodium, potassium, osmolality and free water among mice of 24 inbred strains and F1 hybrids. These differences were detectable in spite of high within-strain variations. Even under highly standardized conditions about 50% of the total variance was ascribed to the within-strain component. Males showed more significant strain differences than females, and there were more differences between strains for osmolar and free water clearances than for sodium or potassium. Most environmental correlations were not significant, while many significant genetic correlations were found between the clearances and bodyweight and, less strongly to kidney weight. Bodyweight was therefore selected as a common base, and the exponent was about 0.80 for both sodium and potassium clearance.

Animals↗
PubMed1981

Genetic analysis of renal function in mice. 1. Glomerular filtration rate and its correlation with body and kidney weight.

Investigation of 18 inbred and 6 F1 hybrid mouse strains has shown that the glomerular filtration rate, bodyweight and kidney weight showed strain- and sex-dependent differences. Covariance analysis showed stronger correlations (genetic and environmental) between glomerular filtration rate and bodyweight than between glomerular filtration rate and kidney weight. This was predominantly due to a high within-strain variation of kidney weight (56%) in male mice. Therefore an allometric regression was calculated between the 48 strain means of glomerular filtration rate (GFR) and bodyweight (BW): GFR = 0.036 x BW0.74. Thus the term BW0.74, a suitable correction term for comparing the heat production of different species, is also suitable for the correction of glomerular filtration rate within one species.

Analysis of Variance↗
PubMed1981

Strain differences in kidney function of inbred rats: 1. Glomerular filtration rate and renal plasma flow.

Bodyweight, kidney weight and glomerular filtration rate showed significant differences between strains--70% of the total variance was ascribed to the between-strain variance component--while the renal plasma flow showed only a slight strain difference due to a high within-strain variance component (63%). Heritability in the broad sense was 0.78 for bodyweight, 0.85 for kidney weight, 0.66 for glomerular filtration rate and 0.35 for renal plasma flow. There were significant genetic correlations between bodyweight and kidney weight (0.90), bodyweight and glomerular filtration rate (0.73), and between glomerular filtration rate and renal plasma flow (0.71), but not between kidney weight and kidney functions. Significant environmental correlations could be calculated only between bodyweight and all other variables, so that for comparison between strains it seems better to correct renal functions for bodyweight than for kidney weight, which would increase the variation of glomerular filtration rate.

Animals↗
PubMed1980

Renal handling of albumin: clearance studies with bovine and rat serum albumin in conscious rats.

The reabsorption capacity of albumin was determined by a clearance technique following a single load of bovine or rat serum albumin in conscious rats. The maximum reabsorption capacity of both albumin amounted to 5.6--6.2 micrograms/min . 100 g BW and there seemed to be a nonselective mechanism for the two albumins. The tubular reabsorption capacity was reached at normal physiological plasma albumin concentration. The renal excretion threshold of both albumins amounted to 31.8 mg/ml, the sieving coefficient phi was calculated to be 2.0 . 10(-4). The glomerular filtration rate, controlled by the total plasma slope clearance of 51Cr-EDTA, remained unchanged following a load of rat serum albumin (54.8 +/- 12.2 ml/min . m2 body surface) but decreased significantly after the administration of bovine serum albumin.

Albuminuria↗
PubMed1980

Proteinuria in rats in relation to age-dependent renal changes.

A variety of sex-dependent urinary proteins of low molecular weight, absent in females and in castrated males, can be identified in male rats by disc electrophoresis. In the urine of male rats of age 5.5 months, albumin comprises only 1-2% of the total protein. Albumin excretion increases greatly with age and associated kidney disease. Total protein excretion, however, stays the same or even decreases slightly as the rat ages, due to a loss of low molecular weight, sex-dependent, proteins. These are virtually absent in senescent rats (38 months of age), although total protein excretion rises tenfold in these animals due to high molecular weight plasma proteins passing into the urine; the glomerular filtration rate decreases to 70% of the value measured at 5.5 months of age.

Aging↗
PubMed1980

Sex differences in kidney morphology and glomerular filtration rate in mice.

The relative kidney weight (1.44% greater than 1.15% greater than 1.07%) and the GFR (44 greater than 39 greater than 35 ml/min . m2) are higher in adult males than in adult females or in orchiectomized males. In contrast, GFR based on kidney weight is smallest in healthy males (1.02 less than 1.22; 1.22 ml/min . g). Only the cortex tissue seems to be increased in males, because its width (1.67 mm) is greater than in females (1.26 mm), while medullary width is identical (2.4 mm) in both sexes. Enlargement of the cortex in males can be accounted for by the nonglomerular tissue, because glomerular diameters (120 micrometers) do not differ and the number of glomeruli in representative sections is lower than in females. Cuboidal cell transformation of the outer layer of Bowman's capsule was observed in 60% of the glomeruli of the males and in 5% of the females. It might be an indicator for hyperplasie of the proximal tubular cells in the males.

Animals↗
PubMedDate not supplied

The Munich Wistar Frömter rat: proteinuria and blood pressure in correlation to the number of superficial glomeruli.

Rats with a high number of superficial nephrons (MWF/Ztm) also show an elevated urinary protein excretion and a high systolic blood pressure. To investigate a possible correlation between the number of superficial glomeruli and these physiological changes, MWF/Ztm rats were crossed and backcrossed to Wistar cryptorchic (WC/Ztm) animals with no superficial nephrons in order to produce genotypes with differing numbers of superficial glomeruli. In the parental strains, the F1 hybrids and the 8 possible backcrosses, the number of superficial glomeruli, the distance of the 10 most superficial glomeruli to the renal surface, and the diameter of Bowman's capsules were determined by morphometric analysis. The excretion of total protein, in detail low molecular weight proteins, albumin, and high molecular weight proteins were measured quantitatively in 5 males of each genotype. Systolic blood pressure was determined by a tail-cuff method in conscious rats. Means of each variate of the 12 available genotypes were linearly correlated and demonstrate a close correlation between the amount of superficial nephrons and the observed physiological changes, i.e. the more superficial the glomeruli the higher the urinary protein excretion, especially albumin, and the higher the systolic blood pressure.

Albuminuria↗