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Biomedical subjects

J Günther

Publications and source records attributed to J Günther.

At least 55 records · Page 3Linked to original sources
PubMed1982

Changes in sarcolemmal K+ -p-nitrophenylphosphatase activity induced by atherogenic cholesterol--rapeseed oil diet in rabbit myocardium.

A high level of plasma lipids may possibly modify the composition and function of cardiac cell membranes and the activity of membrane-bound enzymes. Therefore, the activity of K+ -p-nitrophenylphosphatase (pNPPase) as a part of the Na+ -K+ ATPase was determined in myocardial homogenates to indicate sarcolemmal function after an atherogenic diet. After feeding of a cholesterol--rapeseed oil diet, the total and ouabain-sensitive activities of pNPPase were decreased significantly compared with controls. This decrease in pNPPase activity can be reproduced completely by a pure cholesterol diet. A rapeseed oil diet increases the total and ouabain-insensitive activity of pNPPase. Changes in enzyme activity may be caused by alterations in the lipid surroundings of this membrane-bound enzyme. The inhibition of pNPPase activity by 10(-6) M ouabain was smaller after cholesterol--rapeseed oil and pure cholesterol diets but greater after a pure oil diet. This indicates changes in ouabain sensitivity of pNPPase after various lipid diets.

4-Nitrophenylphosphatase↗
PubMed1982

The influence of atherogenic diet on electromechanical coupling in rabbit myocardium.

To characterize the role of the SR in the electromechanical coupling process in rabbit myocardium after a 12-week-long atherogenic diet containing cholesterol and oil, the influence of changes in Ca2e+ on isometric force, relaxation rate, and resting potentiation of isolated trabeculae were compared with 45Ca2+ binding and uptake by the SR. The diet produces a more strongly expressed resting potentiation of force at 1.25 and 2.5 mM Ca2e+ and an increase in the Vmax equivalent, the contractility index [(dF/dt)max/F'] and the relaxation index [-(dF/dt)max/F]. A higher Ca2e+-accumulating activity of heart microsomes from animals was observed after the diet. It is concluded that changes of SR function are involved in the mechanism responsible for modification of electromechanical coupling induced by cholesterol- and oil-containing diet.

Animals↗
PubMed1982

[Diet induced changes of Ca-regulation in rabbit papillary muscle. 1. Contraction and relaxation following a cholesterol diet].

To characterize consequences of cholesterol induced increases of the Na content on the Ca regulation in rabbit myocardium the influence of increasing extracellular Ca (Cae) on isometric contraction and relaxation of papillary muscles has been investigated after a 12 weeks lasting cholesterol-rich diet. After cholesterol-rich diet increasing Cae caused a higher augmentation in peak tension T, accompanied by a decreased index in contractility [Formula: see text], an insignificantly prolonged time to peak tension TPT, and a decrease in the refractory period, which was extended compared with the control group. A delay in relaxation is demonstrated by the maximum relaxation rate [Formula: see text], the half time of relaxation RT 1/2 and more pronounced by a prolonged relaxation time RT. The results correspond with changes in the Na content published earlier and are in agreement with the assumption that a Na-Ca exchange is involved in beat-to-beat regulation in rabbit myocardium; thereby the cholesterol component of atherogenic diet promotes Ca enhancement in rabbit cardiac cells.

Animals↗
PubMed1982

[Diet-induced changes on Ca-regulation in rabbit papillary muscle. 2. Contraction, relaxation and rest potentialization following a rapeseed diet].

To characterize consequences of rape oil-induced changes on the Ca regulation in rabbit papillary muscle, the influence of increasing extracellular Ca (Cae) on contraction, relaxation and resting potentiation of tension has been investigated after a 12 weeks lasting rape oil-diet. After oil diet increasing Cae caused a similar augmentation in peak tension T accompanied by an increased index in contractility [Formula: see text], a significantly shortened time to peak tension and a decline in refractory period. A higher relaxation rate is demonstrated by the maximum relaxation rate [Formula: see text], the half time of relaxation RT 1/2 and relaxation time RT. The resting potentiation of the isometric contraction was enhanced. The results are in agreement with the assumption that the sarcoplasmic reticulum (SR) is more involved in Ca regulation after the oil diet than in the control group. This may be related to differences in the phospholipid content of SR membranes.

Animals↗
PubMed1981

[Defects in cell-mediated and humoral immunity in tumor-bearing mice. Evidence and characterization of suppressor cells ].

The immune response of mice bearing a transplantable tumor which was induced by Benzyprene was studied. The humoral response to sheep red blood cells (hemolytic plaque assay) is increased until the day 18 after inoculation of the tumor if calculated in relation to the total number of spleen cells, but it is decreased related to 10(6) spleen cells after day 9. Because the weight of the spleen increases during this time this result suggests that the relation between antibody producing and nonproducing cells becomes smaller, despite the total number of antibody producing cells is higher. The unspecific suppression of the cell-mediated immune response in vivo was was studied by the adoptive transfer of spleen cells from tumor bearing mice and allografting of the recipients. The rejection of the grafts is delayed. The stimulation of spleen cells with PHA is smaller with cells from tumor animals than in controls. The fraction which is nonadherent on glass beads has a higher reactivity than the total population, this difference is more distinct in tumor animals. The suppressor cells from tumor mice are glass adherent and their activity is negatively influenced by treatment of the tumor mice with Carageenan.

Animals↗
PubMed1981

On the influence of hydrocortisone on the stimulation of mouse spleen cells by PHA. Evidence for the involvement of suppressor cells.

The stimulation rate with PHA of murine spleen cells increases after removal of glass-adherent cells from the total spleen population. Unfractionated spleen population from HC treated mice suppresses the response to PHA of glass non-adherent cells from untreated animals only 24-48 h after HC treatment. From the third day on after the treatment the suppressive effect disappears.

Animals↗
PubMed1980

[Cytotoxic lymphocytes after allostimulation in vivo: kinetic, reproducibility and specificity after primary stimulation (author's transl)].

After allogeneic skin grafting and allogeneic sensibilization with spleen cells in the mouse system cytotoxic lymphocytes are induced, which can be shown in an vitro assay. The maximum of the cytotoxicity appears 2 to 3 days after transplantation. Cytotoxicity during graft rejection is clearly lower than the maximum cytotoxicity. After 3 to 4 weeks no cytotoxic lymphocytes can be detected. A similar time course is seen after sensibilization with allogeneic spleen cells. The cytotoxic lymphocytes do not react only against the stimulator haplotype if tumor cells are used as target cells. Common specificities between the stimulator and target cells may be responsible for this cytotoxicity. On the other side we found a specific cytotoxic reaction with thymocytes as target cells and in vivo no cross reaction for a second-set graft rejection.

Animals↗
PubMed1980

[Modifications of electromechanical coupling in the rabbit myocardium following cholesterol-oil diet during changing Ca2+ supply].

To characterize the electromechanical coupling in rabbit myocardium after a 12 weeks lasting lipid-rich diet the influence of increasing extracellular Ca2+ on isometric contractions of isolated trabeculae has been investigated. Only after lipid-rich diet the Ca2+-induced augmentation in isometric tension was accompanied by an increase in a Vmax equivalent, in the index of contractility dk/dtmax divided by K', and in the relaxation index -dk/dtmax divided by K. The results correspond with changes in the sarcoplasmic reticulum function reflected in a higher Ca2+ accumulating ability of isolated microsomes.

Animals↗
PubMed1979

[Multilobular biliary liver cirrhosis as a purely hepatic form of mucoviscidosis].

Report about a patient with intraoperative and histological secured multilobular biliary cirrhosis of the liver and local formed purulent bile-duct and gall inflammation as an isolated hepatical form of the cystic fibrosis of the pancreas.--The character was complicated by the development of a portal vein high pressure and esophagus varicose vein haemorrhage, who at once needed a Shunt operation. Fromout the point of our view Sulprim is a good way to the therapie of purulent bile-duct inflammation in the case of cystic fibrosis of the pancreas.

Child↗
PubMed1979

[Function of the rabbit myocardium sarcoplasmic reticulum and the resting potentiation of isolated trabeculae following cholesterol-oil feeding].

It is assumed that the resting potentiation of contraction corresponds to the Ca accumulating activity of the sarcomplasmic reticulum (SR). To test this supposition, resting potentiation and Ca transport by isolated microsomes of the heart were compared. The experiments were done in isolated trabeculae and in hearts of rabbits which had received a lipid-rich diet for 12 weeks. Preparations of control animals were used for comparison. Resting potentiation of the isometric contraction as well as Ca binding and Ca uptake were enhanced by the lipid-rich diet. The results confirm the strong relation between the resting potentiation of contraction and the Ca accumulating activity of the SR. The increased Ca transport may be related to differences in the lipid content of SR membranes.

Animals↗
PubMed1978

[Mechanical characteristics of isotonic work and high-energy phosphates in frog ventricle after 1-fluoro-2,4-dinitrobenzene].

The blocking of the creatinphosphokinase by 1-fluoro-2,4-dinitrobenzene (FDNB) allows to investigate the relationship between ATP-supply, contractility and relaxability of the frog's myocardium. In isotonically working isolated ventricles of frogs the time of work, systolic and diastolic volume, velocity of contraction and relaxation as well as the levels of CP, ATP, ADP and AMP were measured at different intervals until termination of each experiment. CP shows a small variation, ATP decreases to 60% and ADP + AMP increase for the same amount under FDNB during the development of a slight inhibition of contractility and a continuously growing inhibition and retardation of relaxation until systolic arrest. ATP content and volume of relaxation correlated strictly. The contracture and the diminished contractility are caused by the decrease of ATP, producing a lack of substrate for Ca transport and actin-myosin-ATPase. This models the course of events during an insufficiency like in angina pectoris and in myocardial infarction.

Adenine Nucleotides↗
PubMed1978

Evidence of suppresssor cell-mechanism of allograft tolerance induced by spleen extract and hydrocortisone.

The mechanism of allograft tolerance in mice induced by cell-free spleen extract in combination with hydrocortisone was investigated. HC potentiated tolerance induction when given after the spleen extract. When HC was given before, or during the first 2 weeks of antigenic treatment, it counteracted rather than potentiated the tolerance-inducing effect. Spleen or lymph node cells transferred from tolerant donors to untreated or sublethally irradiated syngeneic recipients suppressed the recipients' response to the particular alloantigens. The suppressive activity of lymphoid cells from tolerant donors was abolished when before their transfer the subpopulation of T cells was eliminated by means of anti Thy-1.2 serum and complement. This finding suggests that suppressor T cells may be involved in tolerance induced by spleen extract and hydrocortisone.

Animals↗
PubMed1978

[Ultrastructural and functional changes of rabbit myocardium after cholesterol feeding].

The myocardium was ultrastructurally investigated immediately after 12 weeks of feeding in one part of the animals and in the remaining animals 27--30 months after termination of the feeding period. At the same time, parameters of the myocardial contraction were measured immediately after the feeding at isolated trabeculae of the left ventricle and 27--30 months after the termination of the feeding at the left ventricle in situ. After the 12 weeks of feeding the morphometrically estimated intracellular lipid content rises from 0.23% (normal) to 5.26%. The mitochondria decline from 36.98% (normal) to 29.08%. The sarcoplasmic reticulum (SR) changes in a vesicular or vacuolar manner respectively. The contractility index Vmax of isolated trabeculae decreases insignificantly. The resting potentiation and the diastolic stiffness are increased. 27--30 months after termination of feeding the lipid content and the mitochondria are normal in comparison to controls of the same age. The vacuolar changes of SR and its cellular portion are increased. The contractility index of the heart in situ max (dp/dt)/P is decreased insignificantly. The velocity of relaxation is enhanced in comparison with controls. By comparing ultrastructural and functional findings it can be seen that variations in the contraction performance are accompanied by stronger changes of the cellular structure immediately after the feeding than 27--30 months after the termination of the feeding. At this time continuing small alterations in the contraction performance of the heart in situ are observed in addition to the reversibility of various characteristics of damage together with an increase in the Ca++-transporting SR and its alterations.

Animals↗
PubMed1978

[Changes in the excitation contraction coupling in the myocardium of rabbits fed a cholesterol-containing diet].

It was of interest whether a hypercholesterolemia after feeding a diet containing 2 g cholesterol in sunflower oil per day during 12 weeks induces changes of the myocardiac cells of rabbits which must not necessarily be the consequence of a diminished bloodstream on account of coronary stenosis or the consequence of a lesion of the wall of the vessels. The contractile force and the indirectly measured shortening velocity of the isometrically working papillary muscle out of the left ventricle were not reliably changed. As a result of the feeding the isometric force rose after paired pulse stimulation and after a pause during the rhythmic action, although a considerable deposition of fat within the cells and disseminated necrosis in the myocardium could be observed. Because of the increasing loss of sodium into sodium-free solution in parallel with an increasing sodium content of the myocardium it has been concluded that the permeability of the cell membrane for this ion should be elevated. Furthermore it is assumed that the activation of the ionic pumps is elevated which is recognizable from a higher positive inotropic action of both the application of strophanthine and the substitution of NaCl by LiCl. But it seems that one elevation could not completely compensate the other one. The mean value of the velocity of relaxation related to the isometric force was increased. It has been postulated that after the diet rich in cholesterol and sunflower oil the cardiac cell shows a retarded restitution of the contraction during the interval between beats and elevated content of calcium. This may be one of the causes for the observed necrosis besides the ischemic component of the injurant feeding.

Animals↗