Systematic investigation of degradation effects on spin-lattice relaxation times in mouse-liver by low resolution NMR.

In spite of numerous work on in vitro proton relaxation time investigations of biological tissue, many questions still remain open. In this study we focused on spin-lattice (T1) relaxation time measurements of mouse liver tissue in order to estimate the time-after-excision effects. The post mortem behaviour of excised tissue was measured up to four hours in intervals of about nine minutes. The time course of liver T1 was determined for different temperatures (4 degrees-40 degrees C) for female mice and the effect of starvation (up to 48 hours) on the time course of T1 was investigated for male and female mice at 37 degrees C. We obtained significant differences in liver T1 time course after excision due to different physiological states like sex, starvation and circadian rhythm.

[The flight behavior of hand grenade fragments and their shock-producing effect on the human]. / Untersuchungen über das Flugverhalten von Handgranaten-splittern und ihre schockauslösende Wirkung am Menschen.

Systemic affects by multiple hits of corpuscular material are not seen until a level of ergy about 600-800 J is reached. A major determinant is the sum of energy. A potentiating effect could not be observed. Enduring casualties are expected by vital hits only, but heavy pains are able to induce serious handicap. The old rule of soldiers to avoid strong injuries, to lie nearby an armed handgrenade which is not possible to be thrown away seems to be corroborated by the present facts.

Systematic investigation of degradation effects on spin-spin relaxation times in mouse-liver by low resolution NMR.

Despite numerous work on spin-lattice (T1) relaxation in vitro, not much attention has been paid on spin-spin (T2) relaxation until now. In this study we are presenting spin-spin relaxation time measurements of mouse liver tissue in order to estimate the time-after-excision effects. The post mortem behaviour of excised tissue was investigated up to four hours in intervals of about nine minutes. The time course of liver T2 was determined for different temperatures (4 degrees - 40 degrees C) for female mice. In order to describe the similar behaviour of T2 and pH changes in mouse liver after excision, we are suggesting an empirical model to correlate this data. In contrast to T1 results published recently, we found no significant differences in liver T2 time course after excision due to different physiological states like sex, starvation or circadian rhythm. T1/T2-behaviour after tissue excision is discussed in an attempt to separate various relaxation mechanisms.

Influence of some uremic toxins on oxygen consumption of rats in vivo and in vitro.

According to our present knowledge hypometabolism and hypothermia in uremia are most probably due to direct actions of toxic substances at the cellular level. A cardiovascular etiology seems less possible. A similar reduction of oxygen consumption as observed in uremia can be produced by 5 mg/kg body wt. indole i.p. Acetoine, m- and p-cresol, methylguanidine and putrescine do not reduce oxygen consumption even at tenfold higher doses. Some combinations of these substances, however, are effective when given only 10 mg/kg body wt. each. The effects in vivo cannot be reproduced by employing in vitro systems.

Metabolism of free fatty acids (FA) and triacylglycerol (TG) in acute and subacute fluoride intoxication of the rat.

In rats acute intoxication with 100 mg sodium fluoride/kg body wt. orally has the following metabolic consequences. Oxygen consumption is reduced by about 30-50%. Plasma free FA decrease in fed as well as in starved rats. Hepatic FA synthesis is enhanced, but TG secretion to the blood is not altered. Intravenously injected Intralipid 20% is removed at a normal rate. In subacute intoxication (30 mg sodium fluoride/kg body wt given orally per day over 1 week) oxygen consumption is not affected. TG secretion and removal of Intralipid remain in the normal range whereas hepatic FA synthesis is increased as in acute intoxication. TG concentration in the liver, however, increases by about 30% after 1 week.

Reduced hepatic fatty-acid synthesis and lowered plasma triacylglycerol (TG) in potassium deficient rats.

Potassium deficiency was induced in rats by feeding a potassium- free synthetic diet containing 5% Resonium A. Feeding this diet for 1 week resulted in a decrease of plasma potassium by about 50% vs. pair fed controls. In hypokalemic rats hepatic fatty-acid synthesis and TG secretion by the liver were significantly reduced. In contrast the removal of an intravenous lipid load occurred optimally under this condition. As a consequence plasma TG levels were reduced in potassium-deficient rats.

Increased serum triacylglycerol and cholesterol binding reserve in acute uremic rats.

In acute uremic rats (24 h after bilateral nephrectomy, serum urea 280-300 mg/dl) the interface tension of the serum is significantly reduced. Serum levels of triacylglycerol are significantly elevated in uremia, whereas cholesterol levels do not show a significant alteration. The in vitro serum binding reserve for both, triacylglycerol and cholesterol is considerably enhanced. These results let suppose the presence of tenside-like substances in uremic serum which may be involved in disturbed triacylglycerol transport from the serum to the tissues and in development of uremic hypertriglyceridemia.

[On the effect of cadmium on tissue respiration and gluconeogenesis in rat kidney cortex (author's transl)]. / Zur Wirkung von Kadmium auf Gewebsatmung und Glukoneogenese in der Nierenrinde von Ratten.

Oxygen consumption (QO2), respiratory quotient (RQ) and gluconeogenesis of rat kidney cortex slices were determined (Warburg technique). QO2 was not influenced by 0.01 mM CdCl2 in the incubation medium (no exogenous substrate added), 0.1 mM, 1mM and 10 mM, respectively, reduced QO2 by 43%, 45% and 68%. In the presence of 8 mM glucose, 10 mM acetate or 5 mM butyrate, 1 mM Cd resulted in a decrease in QO2 by about 50% each. Addition of 20 g/l albumine to the medium abolished this effect of cadmium. RQ was not influenced by a mM Cd, both without and with 8 mM glucose in the medium. Glucose production from 7 mM pyruvate or 5 mM glutaminate in slices from fed and starving rats was reduced by 1 mM Cd to half the value found in controls.