Effect of 6-Aminonicotinamide on the activity of hexokinase and lactate dehydrogenase isoenzymes in regions of the rat brain

Changes in the activity of hexokinase and lactate dehydrogenase isoenzymes in the three brain regions and heart were studied in the 6-Aminonicotinamide-treated rats. Drug administration decreased the particulate hexokinase and lactate dehydrogenase activity, but increased the soluble hexokinase     

Sub-banding and fine structure of serum lactate dehydrogenase isoenzymes induced by sulfur compounds

Human serum was incubated 1:1 by volume with solutions of several sulfur compounds of pH 7.2 for at least 24 hours and the total LDH-P determined and the distribution of LDH isoenzymes and fine structure examined by polyacrylamide disc electrophoresis. As with penicillamine, the disulfide but not N-acetyl-penicillamine, caused removal of LDH-5 without affecting the total unitage. The latter was depressed by thiophenoxyacetate (0.10-0.40 M), undiluted dimethyl sulfoxide and levamisole (0.025 M and higher) but not by the last agent at 0.0005-0.001 M which gave rise to fine structure in the gels. As screened in a number of sera of 160–2300 U/L in total LDH, phthalyltetrathioacetate (0.2-1.0 M) elicited 3 unique sub-bands as pre-LDH-2, pre-LDH-3 and pre-LDH-4 to the exclusion of any effect on the total LDH.     

Alterations in lactate dehydrogenase isoenzymes and phosphofructokinase activity in the hormonally induced G-XII cell line

G-XII cell line was earlier developed in our laboratory from the granulosa lutein cells of goat ovaries, subjected to sustained stimulation by ovine luteinizing hormone. It is a non-clonogenic and non-tumorigenic cell line which secretes progesterone. In the present paper, we report some biochemical findings on the cell line studied between passages 10 and 15. The cells exhibited a shift in the lactate dehydrogenase isoenzyme pattern from the heart form to muscle form and a 300% increase in the phosphofructokinase activity compared to fresh granulosa cells.     

Effect of thyroid hormones on the activity of pyruvate kinase and lactate dehydrogenase in mature rat brain

The enzymatic activities of two "key" enzymes of the glycolytic pathway, pyruvate kinase and lactic dehydrogenase, were studied in seven areas of the brain in male adult rats in states of pharmacologically induced hyper and hypothyroidism. The brain areas were: anterior cortex, adenohypophysis, hypothalamus, amygdaline nucleus, septum, hippocampus and cerebellum. In T3 treated animals, pyruvate kinase activity showed significant increase in all the areas studied while lactic dehydrogenase activity decreased. In propyl-thiouracil treated animals these enzyme activities showed no significant variations from those in animals of the control group.     

Sinusoidal profiles of lactate dehydrogenase activity in rat liver

Summary Lactate dehydrogenase activities were measured along two sinusoidal paths (1) between small portal tracts and central veins and (2) between regions of adjoining septal branches and central veins in the livers of male Wistar rats, using a Lowry technique. The established profiles of enzyme activity provide further support of functional heterogeneity of liver sinusoids and their abutting hepatocytes related to morphological differences of the sinusoidal bed. Within the hepatocytes a pronounced heterogeneity in enzyme activity was recorded surrounding small portal tracts and central veins. The lowest values of activity were determined in those cells located in close proximity to the vessels, which emphasizes their exceptional morphological and functional position.Supported by grants of the Forschungsförderung des Landes Nordrhein-Westfalen, No. 40002585 and the Verein der Freunde und Förderer der Universität KölnDedicated to Professor Dr. Dietrich Eichner on the occasion of his 65th birthday     

The effect of training and detraining on lactate dehydrogenase isoenzymes in the horse

In the horse, total LDH activity increased with training and the H and M subunit activity parallelled this increase. It is suggested that these increases are in response to a stimulus from the type of training program utilised. The first half of a detraining program decreased the activity of the H and M subunits as might be expected. A sharp rise in the total LDH and the M subunit activity occurred during the latter half of the detraining program. This unexpected increase may be due to relatively more hypoxic conditions prevailing in the muscle during the detraining period.     

Sinusoidal profiles of lactate dehydrogenase activity in rat liver

Lactate dehydrogenase activities were measured along two sinusoidal paths (1) between small portal tracts and central veins and (2) between regions of adjoining septal branches and central veins in the livers of male Wistar rats, using a Lowry technique. The established profiles of enzyme activity provide further support of functional heterogeneity of liver sinusoids and their abutting hepatocytes related to morphological differences of the sinusoidal bed. Within the hepatocytes a pronounced heterogeneity in enzyme activity was recorded surrounding small portal tracts and central veins. The lowest values of activity were determined in those cells located in close proximity to the vessels, which emphasizes their exceptional morphological and functional position.