Effect of consumption of green and black tea on the level of various enzymes in rats

Drinking of both green and black tea as the only liquid ingested resulted in significant decreases in the activity of transketolase in whole blood of rats both before and after the in vitro addition of thiamin diphosphate. Liver transketolase activity was decreased only by green tea. Mucosal transketolase activity was not affected by either type of tea. The activity of lactate dehydrogenase (LDH) was not affected by either type of tea, while whole blood LDH was decreased by both green and black tea. Neither tea had any affect on mucosal alkaline phosphatase, but thiamin diphosphatase activity was decreased by both teas. An increase in liver total thiamin resulted from the drinking of both types of tea.     

Transketolase and 2-oxoglutarate dehydrogenase activities in the brain and liver of the developing rat

Summary Rat brain transketolase showed little change in activity from birth to adulthood, whereas the liver enzyme activity increased in a biphasic way. In both brain and liver, 2-oxoglutarate dehydrogenase activity increased gradually after birth and reached a plateau at 5 weeks of age. A developmental change in thiamin content in the brain was similar to the change in the 2-oxoglutarate dehydrogenase activity, but this was not the case in the liver.     

Effect of retinyl acetate feeding on the activity of testicular enzymes in young rats

Summary Feeding of excess vitamin A significantly increased the activity of -galactosidase and -glucuronidase without effecting the activity of acid and alkaline phosphatase in rat testicular homogenates. It is suggested that imbalance of vitamin A affects the normal process of spermatogenesis by altering the activity of lysosomal enzymes.Acknowledgments. The author is grateful to Dr C.M. Singh, I.V.R.I., Izatnagar and Dr L.N. Singh, for providing facilities and encouragement and to Prof. O. Isler, Hoffmann-La Roche, Basel, Switzerland, for the generous supply of retinyl acetate used in this work.     

Effect of cobaltous chloride on the blood sugar level and the islet cells in rats

Résumé L'effet de l'administration de chlorure de cobalt chez le rat normal est une hyperglycémie prononcée dans l'espace de quelques heures après l'injection. Il n'est pas possible de déceler des changements dans les cellules des îlots de Langerhans. Les noyaux des cellules ne montrent qu'une diminution faible après 24 h de l'injection.     

Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in humanAscaris lumbricoides

Summary The phospholipid level in the human parasitic nematodeAscaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.Acknowledgment. We thank ProfessorP. A. Kurup of this Department for keen interest and helpful advice.     

Effect of piperazine on the level of phospholipids and on the activities of certain enzymes of phospholipid metabolism in human Ascaris lumbricoides.

The phospholipid level in the human parasitic nematode Ascaris lumbricoides is decreased by piperazine, by partially stimulating catabolic enzymes such as phospholipase C and partially inhibiting anabolic enzymes such as choline kinase.     

Effect ofBordetella pertussis vaccine on plasma corticosterone level and on ACTH-induced corticosterone secretion in rats

Zusammenfassung Der Corticosteron-Gehalt des Rattenplasmas wurde durch BPV-Behandlung vorübergehend reduziert, obwohl die ACTH-Wirkung auf den Corticosteron-Spiegel im Plasma unverändert blieb.     

Effect of streptozotocin diabetes on adenosine-5′-triphosphate,oxygen consumption and steroidogenesis in testis mitochondria from rats

Summary The activity of the enzyme cleaving the side-chain of cholesterol (rate limiting step in steroidogenesis) was considerably reduced in experimentally induced diabetes. This result was accompained by both an increase in oxygen consumption and an increase in ATP synthesis. Insulin treatment prevented them.     

Effect of halogenmethylenebisphosphonates on bone cells in culture and on bone resorption in vivo

Summary Dihalogenmethylenebisphosphonates increase alkaline phosphatase activity and fatty acid oxidation in calvaria cells in culture (Cl₂MBP>Br₂MBPF₂MBP). The monohalogen C1MBP and the non-halogenated analogues are less active on phosphatase and inactive on or inhibitory towards fatty acid oxidation. The three dihalogenbisphosphonates and C1MBP inhibit bone resorption in vivo, Cl₂MBP most strongly.Acknowledgments. We thank Miss M.-L. Aebersold, Miss J. Portenier, Mrs I. Tschudi and Mrs Ch. Marti for their skilled technical assistance. This work has been supported by the Swiss National Science Foundation (grant 3.937.82), by the Procter & Gamble Company, Cincinnati, USA, by the Istituto Gentili S.p.A., Pisa, Italy, and by the Ausbildungs- und Förderungsfonds der Arbeitsgemeinschaft für Osteosynthese (AO), Chur, Switzerland.     

Effect of X-rays on the proteolytic enzymes of granulocytes and on phagocytosis index in guinea-pigs

Résumé Après l'exposition du cobaye aux rayons X, nous avons constaté l'affaiblissement des enzymes granulocytaires suivants: la protéase acide, la protéase alcaline, le plasminogène, l'activateur du plasminogène, l'activité fibrinolytique spontanée. L'index de la phagocytose n'a diminué qu'au 20e jour après l'irradiation.     

High altitude influence on the level and turn-over time of cardiac norepinephrine in rats

Summary In rats exposed to an altitude, of 2,900 meters the level of endogenous cardiac norepinephrine decreases after the 5th day of exposure. The turner-over time of the amine proceeds in 3 steps which are probablyrelated to periods of stress and adaptation: initial increase, important decrease from the 5th day and return to a normal value from the 12 th day.     

Effects of glycolytic metabolites on preservation of high energy phosphate level and synaptic transmission in the granule cells of guinea pig hippocampal slices

The present study was undertaken to investigate whether neural activity of hippocampal slices can be preserved after replacingd-glucose with glycolytic intermediate metabolites such as lactate, pyruvate and citrate or with other sugars such as fructose, mannose, maltose, glucosamine, sucrose and galactose. As an index of neural activity, population spikes (PS) were recorded in the granule cell layers after electrical stimulation to the perforant path of guinea pig hippocampal slices. In addition, we determined the levels of ATP and creatine phosphate (CrP) in each slice after the replacement ofd-glucose with these substrates, and correlated it with the neural activity. Substrates other thand-glucose could not maintain the PS for even 20 min although the slices perfused with medium containing lactate, pyruvate, galactose, fructose and maltose maintained similar levels of ATP and CrP as in slices incubated in thed-glucose-containing medium. These results indicate thatd-glucose is essential for the preservation of synaptic activity in addition to its main role as the substrate for energy production to maintain the levels of high energy phosphates.     

Differential influences of various arsenic compounds on glutathione redox status and antioxidative enzymes in porcine endothelial cells

The cellular response and detoxification mechanisms in porcine endothelial cells (PAECs) to arsenic trioxide (As2O3), sodium arsenite (NaAsO2) and sodium arsenate (Na2HAsO4) were investigated. NaAsO2 at 20 microM for 72 h increased Cu/Zn superoxide dismutase activity resulting in elevated intracellular hydrogen peroxide levels, but As2O3 and Na2HAsO4 did not. Trivalent arsenic compounds increased intracellular oxidized glutathione (GSSG) and total glutathione (GSH) and cellular glutathione peroxidase (cGPX) and glutathione S-transferase (GST) activity, but not glutathione reductase activity. The increased cGPX activity resulted in an elevated cellular GSSG content. Na2HAsO4 increased the cellular GSSG level at 72 h compared to controls. These results imply that the increased GSH content responding to the oxidative stress by trivalent arsenic compounds may be mainly related to the regulation of GSH turnover. The increased GST activity implies that the elevated intracellular GSH level responding to the oxidative stress may be used to conjugate arsenic in PAECs and facilitate arsenic efflux.     

Hormonal control of pheromone responsiveness in the male black cutwormAgrotis ipsilon

In Lepidoptera, reproduction is linked to chemical communication between conspecific partners. When exposed to the female sex pheromone, males respond by exhibiting typical sexual behaviour which leads to mating. Here we show that presence of the juvenile hormone producing gland (corpora allata) of the male black cutworm,Agrotis ipsilon, is necessary for pheromone responsiveness. Allatectomized males do not show any sexual behaviour, although their antennal olfactory system is functional. Allatectomized males implanted with active corpora allata recover full pheromone receptivity. It is suggested that reproductive processes are synchronized in males and females through endocrine control; timing of the mating activity could serve as an adaptive strategy linked to the migratory behaviour of this species.