Effects of Freund's complete adjuvant on the dirunal rhythms of neuroendocrine processes and ornithine decarboxylase activity in various tissues of male rats

The aim of this study was to investigate the effects of Freund's complete adjuvant (FCA) on the diurnal rhythms of hormonal parameters in serum and ornithine decarboxylase (ODC) activity in various tissues of male rats. On days 1–2 after FCA, increase of ODC activity (used to evaluate the level of activation) was observed in the hypothalamus, pituitary gland, adrenal medulla, adrenal cortex, liver and lymphoid tissues, while the ODC activity in the kidney was reduced. This was accompanied by an increase in serum corticosterone. On days 3–4 after FCA, ODC activity remained elevated in the pituitary gland, liver and lymphoid tissues, while the ODC activity in the testes and panceas was reduced; kidney ODC activity returned to baseline. This was associated with increased serum levels of prolactin (Prl) and luteinizing hormone, but decreased growth hormone, testosterone and insulin. The increase in ODC activity in the thymus, as well as the reduced ODC activity in the testes and kidney, can be obtained with paraffin. Furthermore, bromocryptine microcapsules (CBLA) reduced the FCA-induced increase of ODC activity in the pituitary gland, liver and lymphoid tissues (days 3–4) but did not affect the changes in other tissues. The increase in ODC activity in the pituitary gland, liver and lymphoid tissues is specific for FCA. A role for Prl in the induction of ODC in liver and lymphoid tissues is suggested by the fact that CBLA suppresses this enhancement.     

Administration of D-alanine did not cause increase of D-amino acid oxidase activity in mice.

D-amino acid oxidase (DAAO) activity was not altered in the liver and kidney by oral administration of D-alanine to adult mice. The enzyme was apparently not induced by the enteric microflora either, since the enzyme activity in the liver and kidney of germ-free mice was not different from that of specific-pathogen-free mice. The times of appearance of DAAO activity and of free D-amino acids in the kidney were elucidated using suckling mice. DAAO activity started to increase 7 days after birth, and reached almost the adult level by 28 days. The content of free neutral D-amino acids also increased with age, in a similar fashion. A possible conclusion is that the enzyme activity normally increases during this period, to eliminate the free D-amino acids which have increased with age in the suckling mice. Consequently, the administration of D-alanine had no further effect in increasing enzyme activity.     

稻草还田少免耕对稻田土微生物及酶活性的影响

为探明少免耕和稻草覆盖对土壤生物特征的影响，合理利用稻草覆盖及耕作制度来保障土壤的可持续利用，研究了33％（约2500ks／hm^2）、67％（约5000kg／hm^2）、100％（约7500kg/hm^2）稻草覆盖少免耕对稻田土微生物区系及活性的影响。定位试验2年后，少免耕与稻草覆盖提高了稻田土好气性细菌数量、真菌数量和微生物活度，但厌气性细菌和放线菌的数量则略减少。33％和67％稻草还田时，翻耕土壤的好气性细菌和厌气性细菌数量均高于免耕和少耕土壤。33％稻草还田时，免耕和少耕土壤的放线菌和真菌数量均高于翻耕土壤。同时，少免耕提高了土壤木聚糖酶、纤维素酶、蛋白酶、脲酶、过氧化氢酶的活性，也提高了土壤微生物活度、氨化作用强度和硝化作用强度。少量稻草还田少耕要优于少量稻草还田翻耕和免耕。     

Lactate dehydrogenase activity in cell subpopulations of 7,12-dimethylbenz(a)anthracene-induced mammary tumors

Heterogeneity of cells in a solid tumor prevents direct assessment of enzyme activity of cell subpopulations by conventional homogenization techniques. Lactate dehydrogenase (LDH) activity before and after ovariectomy and following estrogen supplementation in density-defined cell subpopulations from DMBA-induced mammary tumors was determined. Different levels of LDH activity were found in different cell subpopulations. After ovariectomy the level of LDH activity declined. Restoration of the circulatory estrogen level resulted in increased enzyme activity. The highest level of LDH was found in a band which consisted mainly of poorly differentiated cells. This cell subpopulation also tended to be more responsive to endocrine manipulation.     

Species-specific differences in the mitogenic activity of heparin-binding growth factors in the sera of various mammals

Sera from different mammalian species displayed great differences in mitogenic activity, as measured by stimulation of DNA synthesis in BALB/c 3T3 cells (3T3 cells). Among the sera examined, fetal bovine serum was least active, and increasing activity was detected in calf serum, human serum, rat serum and mouse serum, in that order. Rat and mouse sera exhibited extremely high mitogenic activity with 3T3 cells, but when TIG-1 human fetal lung fibroblasts were used for the DNA assay instead, the activity levels of all of the sera were lower, and the differences between them were smaller. To determine the reasons for these differences, the heparin-binding growth factors in each serum were separated on a heparin affinity column. Five peaks of DNA-stimulating activity were obtained. Three of these were found in all sera examined, with both 3T3 cells and TIG-1 cells. Two other peaks were found only with 3T3 cells; one was peculiar to rat and mouse sera, with extremely high activity in the rat, and the other was specific to fetal serum. The dependence of the activity of these peaks on the cells used for the test was confirmed using normal rat lung fibroblasts and immortalized rat kidney cells. These findings adequately explain the species-specific differences in mitogenic activity of whole sera, and the variation in activity depending on the cells used for assay of DNA synthesis.     

Lecithin-cholesterol acyltransferase activity in carbohydrate-induced hypertriglyceridemia in mice. An immunofluorescent method for identification of isolated thyrotropic cells

Summary Feeding to mice of both basal as well as high sucrose diet led to increased levels of plasma triglycerides, which was associated with increased lecithin-cholesterol acyltransferase activity. Although males had significantly higher LCAT activity than females in all the dietary groups, sex difference in the plasma triglycerides was observed in high sucrose group only. Increase in plasma triglycerides in experimental groups was associated with an increase in LCAT activity.     

Administration of D-alanine did not cause increase of D-amino acid oxidase activity in mice

D-amino acid oxidase (DAAO) activity was not altered in the liver and kidney by oral administration of D-alanine to adult mice. The enzyme was apparently not induced by the enteric microflora either, since the enzyme activity in the liver and kidney of germ-free mice was not different from that of specific-pathogen-free mice. The times of appearance of DAAO activity and of free D-amino acids in the kidney were elucidated using suckling mice. DAAO activity started to increase 7 days after birth, and reached almost the adult level by 28 days. The content of free neutral D-amino acids also increased with age, in a similar fashion. A possible conclusion is that the enzyme activity normally increases during this period, to eliminate the free D-amino acids which have increased with age in the suckling mice. Consequently, the administration of D-alanine had no further effect in increasing enzyme activity.     

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

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.     

Regional distribution of thiamin pyrophosphokinase in rat brain

The highest specific activity of thiamin pyrophosphokinase was found in the cerebellum, and lower activity in cerebral cortex and midbrain. The regional difference in the enzyme activity was similar to that in thiamin content and the influx rate in rat brain, suggesting that the enzyme is involved in the thiamin transport.     

Long-term motor activity recording of dogs and the effect of sleep deprivation

Summary Motor activity of laboratory dogs was recorded for several weeks with an ambulatory monitoring device. The effect of 24 h sleep deprivation (SD) on motor activity during recovery was investigated. A clear rest-activity rhythm was established. The dogs exhibited a similar mean daily rest-activity pattern: 1) rest occurred mainly in the dark; 2) the amimals were most active after light onset; activity increased during the last two dark hours; 3) a rest period was found at noon and reduced activity during afternoon hours. There was a marked difference in total activity between individual dogs. Activity patterns varied as a function of the day of the week; this may have been a reflection of variations in the level of human activities in the laboratory. There was a significant reduction of motor activity during the 24-h period following SD. This was particularly evident in the first 6 h of the light period immediately following the deprivation.In addition, there was a significant increase in the number of episodes with activity 5 counts during recovery. The study confirms the possibility of measuring motor activity to assess compensatory mechanisms during recovery after SD. Sleep regulation, therefore, does not necessarily need to be exclusively examined by the invasive technique of EEG registration.     

Thiamine-binding activity of Saccharomyces cerevisiae plasma membrane

The specific binding activity to [14C]thiamine was found to be located in hte plasma membrane of Saccharomyces cerevisiae. The activity was inhibited by several thiamine analogs and it was hardly detectable in the plasma membrane from a thiamine transport mutant of Saccharomyces cerevisiae. Some properties of the thiamine-binding activity of yeast plasma membrane are discussed in connection with those of the thiamine transport system.     

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.     

Superoxide dismutase activity in the Spanish population

Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16 +/- 0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.     

Lecithin-cholesterol acyltransferase activity in carbohydrate-induced hypertriglyceridemia in mice

Feeding to mice of both basal as well as high sucrose diet led to increased levels of plasma triglycerides, which was associated with increased lecithin-cholesterol acyltransferase activity. Although males had significantly higher LCAT activity than females in all the dietary groups, sex difference in the plasma triglycerides was observed in high sucrose group only. Increase in plasma triglycerides in experimental groups was associated with an increase in LCAT activity.     

Superoxide dismutase activity in the Spanish population

Summary Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16±0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.     

Regional distribution of thiamin pyrophosphokinase in rat brain

Summary The highest specific activity of thiamin pyrophosphokinase was found in the cerebellum, and lower activity in cerebral cortex and midbrain. The regional difference in the enzyme activity was similar to that in thiamin content and the influx rate in rat brain, suggesting that the enzyme is involved in the thiamin transport.     

Proteolytische Aktivität normaler und antigenstimulierter Makrophagen

Summary The proteolytic activity of polynuclear leucocytes of the guinea-pig was determined prior to and after incubation with the pseudorabies virus (the virus of Aujeszky disease). It was found that the proteolytic activity of leucocytes treated with the virus was increased by 34.5%. There is a brief discussion of the biological value of the increased proteolytic activity.     

Species-specific differences in the mitogenic activity of heparin-binding growth factors in the sera of various mammals.

Sera from different mammalian species displayed great differences in mitogenic activity, as measured by stimulation of DNA synthesis in BALB/c 3T3 cells (3T3 cells). Among the sera examined, fetal bovine serum was least active, and increasing activity was detected in calf serum, human serum, rat serum and mouse serum, in that order. Rat and mouse sera exhibited extremely high mitogenic activity with 3T3 cells, but when TIG-1 human fetal lung fibroblasts were used for the DNA assay instead, the activity levels of all of the sera were lower, and the differences between them were smaller. To determine the reasons for these differences, the heparin-binding growth factors in each serum were separated on a heparin affinity column. Five peaks of DNA-stimulating activity were obtained. Three of these were found in all sera examined, with both 3T3 cells and TIG-1 cells. Two other peaks were found only with 3T3 cells; one was peculiar to rat and mouse sera, with extremely high activity in the rat, and the other was specific to fetal serum. The dependence of the activity of these peaks on the cells used for the test was confirmed using normal rat lung fibroblasts and immortalized rat kidney cells. These findings adequately explain the species-specific differences in mitogenic activity of whole sera, and the variation in activity depending on the cells used for assay of DNA synthesis.     

Ovarian LDH activity in gonadotropin-treated immature rats.

Lactate dehydrogenase (LDH) activity was studied in the ovaries of immature rats treated with pregnant mare serum gonadotropin (PMS). LDH activity increased sharply at 36 h after PMS injection in the ovarian tissue as well as in the blood. It was suggested that the increase of LDH activity in the ovary may be related to its increasing ability to secrete estrogen.     

Long-term 24-hour rest-activity pattern of sheep in stalls and in the field

Summary Motor activity of sheep was continuously recorded for 2–3 weeks with an ambulatory monitoring device. Recordings were obtained from free-ranging animals in the field and from animals maintained under various controlled conditions in stalls. The sheep were diurnal under all conditions. While the daily amount of activity and the frequency of rest episodes showed only small differences between the conditions, the rest-activity pattern showed prominent differences. The pattern differed particularly between the field and the stalls. In the field, activity started to increase one hour after dawn, reaching a first maximum towards noon; a second, higher peak in the evening was followed by a rapid decline after dusk. In the stalls the onset and offset of activity was more abrupt; activity peaks coincided with feeding and human activity; the onset of rest with lights off. Activity was lowest and rest most prominent in those stalls where the animals were most isolated from human influence.