Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among approximately 20,000 apparently healthy subjects whose serum cholesterol and triglyceride (TG) values were screened at a health examination, those with the most pronounced hyperlipidaemia have been selected for further studies. Thus, 188 males and 126 females, aged 30-65 years, with asymptomatic primary hyperlipoproteinaemia (HLP) and 59 male and 69 female controls with non-elevated serum lipids were studied with regard to frequency of ST segment depressions during exercise to near maximal heart rate. Furthermore, the concentrations of cholesterol and TG were determined in the lipoprotein (LP) classes very low (VLDL), low (LDL) and high (HDL) density LP, separated by preparative ultracentrifugation. From the LP analysis each subject's HLP was classified according to the typing system of HLP recommended by the WHO. The frequency of ST depressions (Minnesota code 4.1-4.3 as well as 4.1-4.4) increased with age, was higher in females than in males and was increased in all types of HLP in males. The percentage frequencies of ST depressions 4.1-4.4 in the various types of HLP were (male/female, p against controls): controls 16/36, type IIA 50 (p less than 0.01)/56, type IIB 64 (p less than 0.01)/75 (p less than 0.01)/75 (p less than 0.05), type III 67 (p less than 0.01)/33 and type IV HLP 40 (p less than 0.01/53. There was no significant difference in the frequencies of ST depressions in subjects with "high" and "low" BP (hypertensives were excluded from the study) or in subjects with "high" and "low" k-value for the i.v. glucose tolerance. Non-smokers had a tendency to higher frequencies of ST depressions than smokers. The association between different LPs and other "risk factors" and the occurrence of ST depressions in HLP were studied further with multiple regression analysis. Invariably age was the best predictor of ST depressions. The LP fraction giving the highest correlation coefficient was LDL cholesterol in both sexes. VLDL TG and LDL TG were also positively and significantly associated with ST depressions. HDL cholesterol was negatively but insignificantly correlated to ST depressions. When age and LDL cholesterol had been entered into the multiple regression, the only factor giving further significance was VLDL TG in males. Probability tables for the occurrence of ST depressions considering age and different levels of LDL cholesterol and VLDL TG were given. The importance of simultaneous consideration of both VLDL TG and LDL cholesterol in ST segment depression was evident from the tables. Of other "risk factors" (BP, glucose tollerance, smoking, ESR) entered into the regression together with only age and the LPs, only ESR contributed with borderline significance to ST depressions.
...
PMID:Studies in asymptomatic primary hyperlipidaemia. IV. ECG at rest and during exercise and its relation to various lipoprotein classes. 17 Jul 96

In vitro studies have been done on haematopoietic cells from a patient with cyclic neutropenia characterized by severe depression of blood neutrophil levels every 21 days. Serial blood counts reveal periodic fluctuations in neutrophils, monocytes and reticulocytes. Agar culture of marrow cells shows normal concentration of colony forming cells. The percentage of colony forming cells in S phase is highly increased during profound neutropenia and normal during the recovery phase relating the granulocyte production to the peripheral neutrophil level. Studies of ingestion rate, bactericidal activity, lactate production and glucose oxidation during phagocytosis in isolated granulocytes show normal results. Also the ingestion rate in isolated monocytes is normal. Serial karyotype analyses of marrow cells during the neutrophil cycle display a normal pattern. Serum myeloperoxidase levels vary inversely with the peripheral neutrophil count indicating increased granulopoietic activity during profound neutropenia, which might be associated with non effective granulopoiesis during profound neutropenia, leading to a lack of granulocyte reserves in the marrow.
...
PMID:Cell production and cell function in human cyclic neutropenia. 17 16

Insulin accelerates the entry of glucose and amino acids into muscle cells by acting upon the 'carrier-facilitated' transport mechanism. For glucose this process is passive and leads to equilibration of intracellular and extracellular concentrations. In heart muscle, glucose transport is a rate-limiting step for glucose uptake. During hypoxia and ischemia the heart turns to anaerobic glycolysis for energy production and therefore, maximal glucose transport becomes important. Insulin is necessary to insure proper protein synthesis, probably at the level of membrane-bound polyribosomes. However, during myocardial hypoxia, insulin alone cannot restore the associated depression in protein synthesis. Although insulin hyperpolarizes the cell, a change in the ratio of intracellular to extracellular activities of potassium is not its primary mode of action. An insulin-induced configurational change in the plasma membrane could simultaneously account for the effects of insulin on sodium and potassium permeability and the action on facilitated transport. Intracellular levels of cyclic adenylate may be reduced by insulin in adipose tissue because of inhibition of adenyl cyclase or stimulation of phosphodiesterase. However, at this time there is little evidence that insulin alters cyclic AMP levels in the heart. Insulin secretion is depressed in patients with heart disease in proportion to the reduction of cardiac index sustained. Since the ischemic heart is dependent upon glucose as the major fuel, insulin lack may deprive the heart of adequate substrate.
...
PMID:Insulin: fundamental mechanism of action and the heart. 18 67

The effects of chronic oral ingestion of lead in doses ranging from 20-80 ppm were compared with those seen after the subacute exposure of rats to a 10 mg/kg daily dose of the heavy metal for 7 days. Irrespective of the treatment regimen used, lead treatment significantly increased the activities of renal pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose 1,6-diphosphatase and glucose 6-phosphatase. The observed enhancement of kidney gluconeogenic enzymes in chronically treated animals was associated with a stimulation of the adenylate cyclase-cyclic AMP system, a rise in blood blucose and urea as well as a depression in hepatic glycogen and serum immunoreactive insulin (IRI) levels. In contrast, subacute exposure to lead failed to significantly alter cyclic AMP metabolism and the concentrations of liver glycogen, blood glucose, serum urea or IRI. Whwereas the insulinogenic index (the ratio of serum IRI to blood glucose concentration) was markedly suppressed in chronically treated rats, this ratio remained within normal limits following subacute exposure to the heavy metal. However, a marked decrease in the insulinogenic index was observed in subacutely treated rats 15 min after the administration of a glucose load. The data provide evidence to show that increased glucose synthesis as well as suppressed pancreatic function may be responsible for lead-induced disturbances in glucose homeostasis.
...
PMID:Effects of subsacute and chronic lead treatment on glucose homeostasis and renal cyclic AMP metabolism in rats. 18 14

The effects of mannoheptulose and DL-glyceraldehyde on glucose-induced insulin release and cycli AMP levels in islets isolated from rat pancreas were investigated. Mannoheptulose inhibition on glucose-induced insulin release was observed after only 5-min incubation period, indicating an inhibitory effect on the early phase of insulin release. This inhibition on insulin release was accompanied with the simultaneous depression of cyclic AMP levels in islets. By the addition of DL-glyceraldehyde to the medium in which glucose and mannoheptulose were present, the depressed cyclic AMP levels in islets were recovered to the control level completely but the restoration of insulin release in the early phase was not complete. In the absence of glucose, DL-glyceraldehyde did not demonstrate a significant increase of insulin release during 5 min incubation, though a marked stimulation was observed after 30-min incubation. Cyclic AMP levels in islets were not affected by DL-glyceraldehyde. When DL-glyceraldehyde was added to the medium with glucose, significant inhibition of glucos-induced insulin release in its early phase was observed without the reduction of cyclic AMP levels in islets. From these findings, the following possibilities are suggested and discussed. 1. Maintenance of the cyclic AMP levels in islets is a necessary but insufficient condition for glucose-induced insulin release particularly for its early phase. 2. Glucose-induced insulin release seems to depend on both the binding of glucose with glucoreceptor and the supply of some metabolites. Mannoheptulose inhibits both mechanisms. DL-glyceraldehyde may supply metabolites but competitively inhibit the binding of glucose to the glucoreceptor.
...
PMID:Effects of mannoheptulose and DL-glyceraldehyde on glucose induced insulin release and adenosine 3',5'-monophosphate levels in isoalted islets of rat pancreas. 18 34

A selective deficiency of uridine triphosphate (UTP) was induced in AS-30D rat ascites hepatoma cells by the synergistic action of D-galactosamine and 6-azauridine. The resistance of these hepatoma cells to low concentrations of D-galactosamine (less than 2 mM) was due to their active de novo pyrimidine synthesis which compensated the trapping of uridylate in the form of uridine diphosphate-amino sugars derived from D-galactosamine. The additional blockage of de novo pyrimidine synthesis led to noncompensated uridylate trapping with a UTP content of less than 0.05 mmole/kg of cell wet weight as compared to the control level of 0.66 mmole/kg. The induction of UTP deficiency by incubating the cells with low concentrations of D-galactosamine and 6-azauridine (0.5 mM each) was not accompanied by significant changes in the content of adenine and guanine nucleotides, uridine diphosphate glucose, and uridine diphosphate galactose. The depletion of UTP pools could be reversed within 10 min by the addition of uridine; orotate or uracil were completely ineffective in these hepatoma cells. A UTP content in the range of 0.1 to 0.4 mmole/kg, induced by either 6-azauridine or D-galactosamine, was associated with a reversible depression of cell growth in suspension culture. A UTP content below 0.05 mmole/kg led to irreversible growth inhibition and to necrocytosis in culture, as well as to a loss of transplantability in vivo. Uridine reversal studies indicated that the percentage of cells able to resume growth in culture decreased with an increasing time period of UTP deficiency. The deficiency period required for irreparable or lethal damage in these hepatoma cells ranged from 3 to 20 hr. The principle of noncompensated uridylate trapping can be extended to other inhibitors of nucleotide synthesis combined with various nucleotide-trapping sugar analogs. Noncompensated nucleotide trapping may be useful for an induction of selective nucleotide deficiencies in tumor cells.
...
PMID:Uridine triphosphate deficiency, growth inhibition, and death in ascites hepatoma cells induced by a combination of pyrimidine biosynthesis inhibition with uridylate trapping. 18 18

The metabolism of 2-deoxy-D-galactose has been studied in AS-30D rat ascites hepatoma cells in suspension. Using 2-deoxy-D-(1-14C)galactose and an alkaline ethanol deproteinization procedure, the quantitatively identified metabolites included 2-deoxy-D-galactose 1-phosphate comprising 99.3%, and UDP-2-deoxy-D-galactose and UDP-2-deoxy-D-glucose, together amounting to 0.4% of the total metabolites. After incubation for 5 h in the presence of 2-deoxy-D-galactose (1 mmo1/1), the content of 2-deoxy-D-galactose 1-phosphate reached 35 mmo1x(kg cells)-1. The rate of phosphorylation of 2-deoxy-D-galactose was rapid during the first 30 min and decreased to approximately 20% of this rate during the subsequent hours. The rapid trapping of Pi in the form of 2-deoxy-D-galactose 1-phosphate resulted in a depression of free intracellular Pi in spite of a concomitant increase in net 32Pi uptake from the medium and a decrease of ATP and other 5'-nucleotides. The rates of glucose utilization and lactate production were depressed by more than 80% in the presence of 2-deoxy-D-galactose (1 mmo1/1). Interruption of Pi trapping by removal of 2-deoxy-D-galactose from the medium reversed the depressions of Pi and ATP and resulted in a rapid but incomplete relief of glycolysis inhibition. Crossover analysis of glycolytic intermediates indicated an inhibition at the 6-phosphofructokinase step. The depression of glucose utilization may be mediated by the increased level of glucose 6-phosphate, a potent inhibitor of hexokinase. An additional inhibitory effect of a metabolite of 2-deoxy-D-galactose at the 6-phosphofructokinase step was indicated by crossover analysis after reversal of Pi and ATP depressions in the presence of a high intracellular content of 2-deoxy-D-glactose 1-phosphate. The quantitative analysis of the metabolites of 2-deoxy-D-galactose demonstrated the predominance of the monophosphate and the negligible formation of UPD derivatives of this sugar analog in AS-30D hepatoma cells. This provides a system for the investigation of a galactose analog as a phosphate-trapping agent in the virtual absence of uridylate trapping.
...
PMID:2-Deoxy-D-galactose metabolism in ascites hepatoma cells results in phosphate trapping and glycolysis inhibition. 19 12

Collagenase digestion of minced lung tissue yielded isolated cells, functionally viable as judged by several metabolic and morphological criteria, representative of all the cell species normally present in the tissue. The efficiency of the isolation procedure was about 25 per cent. Aerobic metabolism was not affected by most of the substrates tested except by succinate which increased oxygen utilization, and glucose, fructose and octanoate which significantly decreased oxygen uptake. Since no significant changes have been observed in the cellular adenine nucleotide content during glucose depression of aerobic metabolism it is concluded that the glycolytic flux had to be sufficient as to account for the decrease in the mitochondrial energy production. The mechanism responsible for these effects as well as their physiological significance are discussed herewith.
...
PMID:Preparation and metabolic characterization of isolated rat lung cells. 19 38

Crude mediators from stimulated rabbit peritoneal leukocytes (LEM) engender numerous physiologic alterations in rats, which are similar to those observed during infection. One hour after the intraperitoneal injection of crude LEM, plasma insulin and glucagon concentrations are elevated; at 2 h the hormonal alterations are manifested by a 30% increase in hepatic cyclic adenosine 3',5'-monophosphate (cAMP), glycogen depression, and uptake of 14C-labeled nonmetabolizable amino acid analogues (AA). Plasma hormone concentrations reach maximum levels by 5 h and decline by 24 h. The hepatic concentrations of AA parallel the insulin and glucagon responses and correlate with the inverse of insulin/glucagon molar ratio. In spite of mobilization of hepatic glycogen evident at 5 h, plasma glucose concentrations were transiently depressed. Plasma insulin, glucagon, and hepatic AA concentrations were dose dependent. Plasma insulin and glucagon responses to crude LEM may explain increases in hepatic cAMP, uptake of AA, and glycogenolysis as well as hypoglycemia. These data partially characterize the role of crude LEM, provide an explanation for the stimuli-inducing hyperglucagonemia and hyperinsulinemia during infection. They implicate the endocrine pancreas as a factor regulating the host's metabolic response to infection.
...
PMID:Effect of leukocytic endogenous mediators on endocrine pancreas secretory responses. 19 70

1 Quantitative studies were made on the glucose release from rabbit liver slices in vitro induced by a range of concentrations of (-)-adrenaline (Ad), (-)-isoprenaline (Iso), glucagon and adenosine 3',5'-monophosphate (cyclic AMP) in the presence and absence of several concentrations of dihydroergotamine (DHE). 2 DHE (3.16 X 10(-6) M) shifted the Ad log concentration-response (LCR) curve to the right and also reduced the maximum response; at a higher concentration (3.16 x 10(-5) M) it produced a greater shift to the right of the LCR curve and caused a reduction in the slope and a larger depression of the maximal responses. The LCR curve to Iso was similarly affected by this higher concentration of DHE. 3 DHE (1 X 10(-5) M) produced no significant effect on the LCR curves of glucagon or cyclic AMP and even at 1 x 10(-4) M DHE caused only a slight depression of the maximal responses to both agonists without any modification of the lower major portions of the curves. 4 These data indicate a selective antagonism by DHE at the rabbit liver adrenoceptor and, since the maximal responses to catecholamines were depressed by a lower concentration of DHE than was required to produce a slight depression of the responses to glucagon and cyclic AMP, the antagonism of DHE against catecholamines does not appear to be at a site beyond the formation of cyclic AMP, but rather at a site more intimately related to the adrenoceptor.
...
PMID:Differences in dihydroergotamine antagonism of glucose release by catecholamines, glucagon and adenosine 3',5'-monophosphate in rabbit liver slices. 21 Aug 74


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>