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

The objective of the present study was to explore metabolic correlates to the appearance of postischemic seizures and the enhancement of brain damage observed in subjects that are made hyperglycemic prior to the induction of ischemia. To that end, transient forebrain ischemia of 10-min duration was induced in normo- and hyperglycemic rats, with subsequent measurements of local CMRglc (LCMRglc) after 3, 6, 12, and 18 h of recirculation. We posed the questions of whether postischemic depression of LCMRglc is exaggerated by preischemic hyperglycemia and whether there are signs of localized increases in LCMRglc in hyperglycemic rats, reflecting subclinical seizure activity. The results confirmed the presence of a long-lasting postischemic depression of LCMRglc in normoglycemic rats. This depression was partially but not tightly related to the degree of reduction of local CBF during ischemia. The depression was most pronounced in neocortical areas and in the hippocampus, but notably it was less pronounced in the densely ischemic caudoputamen. Little or no reduction of LCMRglc was observed in moderately or mildly ischemic structures such as the hypothalamus, red nucleus, and cerebellum. Preischemic hyperglycemia markedly accentuated the postischemic depression of LCMRglc. For example, although the subjects quickly regained wakefulness and motility, they had LCMRglc values in neocortical areas that remained below 50% of control. Corresponding but quantitatively less pronounced reductions in LCMRglc were observed in other areas. Notably, preischemic hyperglycemia reduced postischemic LCMRglc also in areas that showed only moderate to mild reductions in CBF during the ischemia. The results thus demonstrate that preischemic hyperglycemia has pronounced metabolic effects in the postischemic recovery period. The data provide no indication that postischemic seizures, which develop after a recovery period of approximately 24 h, are preceded by the appearance of hypermetabolic "seizure" foci.
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PMID:Preischemic hyperglycemia enhances postischemic depression of cerebral metabolic rate. 273 14

In our previous experiments, a remarkable increase in urinary excretion of glucose was found in rats exposed to 821 ppm trichloroethylene for 12 wk. This was not accompanied with proteinuria, aminoaciduria, phosphaturia and definite histological changes in renal tubular structure. In order to ascertain the mechanism of the increase in urinary glucose excretion, blood glucose level and renal glucose reabsorption were studied in 10 male rats exposed to 783 ppm trichloroethylene for more than 3 wk. Another 10 male rats were studied as control. The following results were obtained: 1. Urine glucose of the trichloroethylene group increased after exposure for 2 wk. All the rats showed glycosuria (above 250 mg/dl) by the 4th week of exposure. 2. Plasma glucose levels were depressed by trichloroethylene to as low as 77% of that of the control group. Glycohemoglobin was similarly decreased. 3. Intravenous glucose tolerance tests (0.5 g/kg load) revealed that decreasing constant of plasma glucose (K value) was elevated by trichloroethylene, suggesting that induced hyperglycemia in the exposed rats improved more rapidly than in the controls. Trichloroethylene did not modify the secretion of insulin after glucose load, regardless of the depression in plasma insulin level before load. 4. Glucose titration tests revealed that tubular transport maximum for glucose (TmG) was decreased by trichloroethylene to as low as 46% of that of the control group. The ratio of TmG to glomerular filtration rate (the theoretical renal threshold for glucose) was also depressed to as low as 55% of that of the control group. The foregoing results indicate that trichloroethylene-induced glycosuria is attributable to deteriorated tubular reabsorption of glucose, and not to hyperglycemia. However, the mechanism for the selective disturbance of renal reabsorption of glucose is yet unknown.
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PMID:[Studies of trichloroethylene-induced glycosuria: blood glucose and renal glucose reabsorption in rats exposed to trichloroethylene]. 275 53

Blood glucose level and forebrain unit activity were simultaneously recorded in rats anesthetized with a ketamine IV infusion. Slight and transient fluctuations in glycemia, occurring either spontaneously or after IV injections of glucose or phlorizin, were observed. The spike frequency of more than 1/3 of the neurons tested in the lateral hypothalamic area was affected by these fluctuations. A majority of the responsive cells displayed either an activation during hypoglycemia or a depression during hyperglycemia. These neurons might mediate the effects of a drop in blood glucose on either meal initiation or neuroendocrine or autonomic events related to nutritional functions.
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PMID:Changes in lateral hypothalamic neuronal activity accompanying hyper- and hypoglycemias. 285 45

Salmon (Oncorhynchus kisutch) somatostatin (sSS; 4 or 8 ng/g body wt) or synthetic Gillichthys urotensin II (UII; 2 or 4 ng/g body wt) were injected intraperitoneally into juvenile freshwater coho salmon. Both sSS and UII caused a dose-dependent increase in plasma free fatty acids (FFA) which diminished with time. sSS induced an initial (1 hr) transient hyperglycemia. By contrast, UII tended to induce hypoglycemia, this effect being significant 5 hr after injection of the higher dose. Both sSS and UII depressed plasma insulin titers 1 hr after injection. By 3 hr, the sSS-associated insulin depression was no longer observed. UII treatment induced a hyperinsulinemia which was present 3 and 5 hr after peptide administration. Although no decreases in liver total lipid concentration or in mesenteric fat total tissue mass were observed, lipolytic enzyme activity within each depot was significantly enhanced by both peptides. Neither sSS nor UII altered 3H2O incorporation into fatty acids or neutral lipids. However, enhanced lipogenesis, particularly by UII, was indicated by increased NADPH production resulting from glucose-6-phosphate dehydrogenase activity. Both sSS and UII enhanced glucose mobilization, as indicated by decreased liver glycogen content and increased liver glucose-6-phosphatase activity. UII, but not sSS, stimulated glycogen synthetase activity. These results suggest that both sSS and UII stimulate hyperlipidemia by enhancing depot lipase activity and that although both factors are potentially gluconeogenetic, sSS seems to be glycogenolytic and hyperglycemic, whereas UII may channel glucose to FFA synthesis.
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PMID:Effects of somatostatin-25 and urotensin II on lipid and carbohydrate metabolism of coho salmon, Oncorhynchus kisutch. 288 97

Steroid sulfurylation represents a potential mechanism for controlling the level of active steroids within a tissue. We have elucidated an inbred strain background-dependent interaction between the diabetes (db) mutation and steroid sulfotransferase (ST) enzymes, potentially modulating the level of active steroid hormones or their precursors in the liver. Gonadectomized mutants were analyzed to correlate how strain- and gender-dependent variation in ST activities interacted with db to achieve diabetogenesis. Both sexes on the C57BL/KsChp (BKs) background developed severe early-onset hyperglycemia, and gonadectomy failed to prevent diabetes. In contrast, C3HeB/FeChp (C3HeB)-db/db males, but not females, were diabetes susceptible, and the male susceptibility was completely dependent upon endogenous testes-derived testosterone. The female resistance, in turn, was dependent upon ovarian sex steroids. The differential requirements of BKs- and C3HeB-db/db males and females for gonadal sex steroids could be explained on the basis of the differential strength of the interaction between the db mutation and hepatic ST activities. Hepatic ST from normal adult females sulfurylated dehydroepiandrosterone (DHEA), whereas this activity disappeared in cytosols of normal adult males by 8 weeks of age. This sexually dimorphic inability to sulfurylate (pre)androgens was controlled by testosterone. Diabetogenic susceptibility in BKs mutant mice of both sexes was associated with marked depression of preandrogen/androgen sulfurylation [female mutants exhibiting at least a 5-fold reduced DHEA sulfurylation at a near-physiological concentration (0.2 microM)]. This reduced preandrogen/androgen sulfurylation occurred concomitant with a 10-fold acceleration of estrone (E1) sulfurylation at a limiting (0.2 microM) concentration, essentially producing a hyperandrogenized hepatic tissue state. These extreme shifts in ST substrate preferences were not observed in the diabetes-resistant C3HeB-db/db females. Kinetic analysis of semipurified hepatic ST from BKs-db/db females showed a 10-fold decrease in Km for E1 (apparent Km = 0.9 microM in mutants vs. 9.0 microM in normals). Whereas the Km for DHEA did not differ from the control value, hepatic ST from BKs-db/db females showed a 10-fold decreased maximal velocity for DHEA sulfurylation (1230 vs. 12750 pmol/mg.h in control preparations). The antihyperglycemic effects of dietary E1 therapy were associated with enhanced androgen sulfurylation in BKs-db/db females and restoration of androgen sulfurylation in BKs-db/db males.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The influence of genetic background on the expression of mutations at the diabetes locus in the mouse. V. Interaction between the db gene and hepatic sex steroid sulfotransferases correlates with gender-dependent susceptibility to hyperglycemia. 291 6

One of the leading causes of mortality in diabetics is myocardial disease. In the past few years this subject has generated a significant amount of interest with the result that myocardial problems associated with diabetes are far better understood. Though originally thought to occur as a result of atherosclerosis, various studies have shown that heart disease can occur in the absence of atherosclerosis, suggesting a diabetic cardiomyopathy. Using diabetic animals, it has been possible to characterize diabetes-induced myocardial abnormalities. Diabetic rat hearts do not respond to conditions of high stress as well as controls. The functional depression is accompanied by altered cardiac enzyme systems. A decrease in myosin ATPase activity which appears to be a result of diabetes-induced hypothyroidism is seen. Also, a depression of sarcoplasmic reticular calcium ATPase, along with a depression of calcium uptake by the SR, is seen in diabetic rat hearts. Na+, K+ ATPase activity has also been shown to be depressed and the depression appears to correlate with depressed atrial contractility. High levels of circulating fats in diabetics may alter the integrity of membranes leading to altered enzyme activities. Insulin treatment has been relatively successful at reversing or preventing myocardial changes in the diabetic rat. Other treatments that have been studied include thyroid hormone treatment, since the depression of myosin ATPase can be corrected by such treatment; and carnitine treatment, as the elevation of long chain acyl carnitines (LCAC) and the resulting depression of calcium uptake in the SR can be so normalized. These treatments have not been successful at normalizing cardiac function. A combination of the two treatments normalized function only partially, suggesting that factors besides myosin ATPase and SR calcium uptake are involved. Other treatments that have been tried include vanadate, methyl palmoxirate, and choline and methionine. Vanadate treatment has proved to be encouraging in that it normalizes both function and hyperglycemia. Methyl palmoxirate, a fatty acid analog, normalized only the elevation of LCAC but did not affect function. Methionine and choline were only partially successful in preventing the functional alterations of diabetic rat hearts. The purpose of the present article is to review our understanding of diabetes-induced myocardial problems and their possible causes. Findings from our laboratory and others are described in which attempts have been made to normalize cardiac function.
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PMID:Diabetes-induced abnormalities in the myocardium. 293 41

Both clinical diabetes and chemically-induced diabetes have been reported to alter control processes of the hypothalamic-pituitary-thyroid axis. One of the sites of alteration appears to be depression of thyrotrophin releasing hormone (TRH) stimulated thyrotrophin (TSH) release. The present study examined the influence of sequential administration of streptozotocin and the goitrogen thiouracil to male mice for 4 weeks in view of their possibly opposing effects on TSH release. The drugs produced the expected results when administered singly, with streptozotocin producing hyperglycemia and thiouracil causing hypothyroxinemia and goitrogenesis. Additionally, thiouracil administration produced hyperinsulinemia. Sequential administration of the drugs appeared to ameliorate the thyroid status and glycemic condition caused by individual exposure. Streptozotocin reduced the goitrogenic influence of thiouracil and thiouracil reduced the hyperglycemia of streptozotocin, but not to control levels. Thus, sequential administration resulted in mice with simultaneously elevated circulating glucose and insulin levels, and depressed thyroxine levels. Similar effects on glucose, insulin, and the thyroxine levels have been reported clinically in patients with non-insulin-dependent diabetes mellitus.
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PMID:Consequences of sequential induction of diabetes mellitus by streptozotocin and hypothyroidism by thiouracil in mice. 294 14

To characterize endogenous control mechanisms for human erythrocyte membrane Ca2+-ATPase ("calcium pump") activity, we studied the effect of changes in blood glucose concentration in vivo within the physiologic range on Ca2+-ATPase activity in red cells. Red cells obtained in the course of induced hyperglycemia were also studied to determine susceptibility of membrane Ca2+-ATPase to stimulation in vitro by thyroid hormone and calmodulin, both of which have been shown previously to enhance Ca2+-ATPase activity. Oral glucose administration (75 g) to eight healthy, adult subjects induced predictable increases in concentrations of blood glucose and immunoreactive insulin. Basal levels of activity of Ca2+-ATPase in red cells obtained after glucose ingestion fell 55% (P less than 0.025) by 30 min after glucose with recovery of enzyme activity to levels not significantly different from basal by 60 min. Activity of red cell Ca2+-ATPase at time zero was significantly stimulated in vitro by thyroxine (T4, 10(-10) M), triiodo-L-thyronine (T3, 10(-10) M), and calmodulin (100 ng/mg membrane protein). In vivo glucose administration led to depression of red cell enzyme responsiveness in vitro to T4 and T3; recovery from this effect did not occur by 120 min after oral administration of glucose. Calmodulin responsiveness of the enzyme in vitro was less significantly reduced in red cells obtained after glucose ingestion. Intravenous (i.v.) glucose administration (20 g) to five subjects also led to decreased basal enzyme activity (61% of fasting level at 20 min). A significant decrease in response of enzyme to T4 was achieved by 8 min after glucose administration (P less than 0.02), with recovery by 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of in vivo glucose administration on human erythrocyte Ca2+-ATPase activity and on enzyme responsiveness in vitro to thyroid hormone and calmodulin. 298 51

Since their introduction in clinical practice in 1980, ACE inhibitors have been found useful in the treatment of hypertension and CHF. In hypertension, they are effective as monotherapy in 40% to 50% of the patients, and in combination with diuretics or calcium antagonists, they are effective in up to 85% of the patients. They are well tolerated, are not associated with depression, impotence, bronchospasm or metabolic derangements such as hypokalemia, hyperuricemia or hyperglycemia, and do not have adverse effects on the quality of life. As a result, they are preferred in hypertensive patients with CHF, left ventricular dysfunction, mental depression, older age, coronary artery disease, metabolic disorders, chronic destructive pulmonary disease, and peripheral vascular disease. In CHF they cause long-lasting hemodynamic and symptomatic improvement, improve exercise tolerance, and may lower mortality in certain patient subsets. Evolving new indications for ACE inhibitors include the diagnosis of renovascular hypertension, the prediction of surgical success, the treatment of scleroderma renal crisis, the reduction of proteinuria, renal protection, cardioprotection, the improvement of arterial compliance, in Bartter's syndrome and idiopathic edema, etc. ACE inhibitors are usually well tolerated but in some instances they may cause class-specific side effects such as hypotension; usually reversible azotemia or renal failure, especially in patients with renal artery stenosis or with CHF with low blood pressure; cough; angioedema; and hyperkalemia. Differences among ACE inhibitors are emerging and include chemical class (e.g., zinc ligand), biotransformation, potency, pharmacokinetics, prodrugs, tissue effects, additional pharmacologic properties, and drug interactions.
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PMID:Angiotensin converting enzyme inhibitors. II. Clinical use. 305 46

The effects of acute doses of soman (40, 60, or 80 micrograms/kg sc) in rats were evaluated for toxic symptoms as well as for changes in plasma levels of glucose, insulin, glucagon, corticosterone, norepinephrine, and epinephrine. The relationship between changes in these levels and depressed acetylcholinesterase activity in the hypothalamus was determined. Soman 40 micrograms/kg did not manifest significant changes in any of the parameters evaluated. However, both the 60 and 80 micrograms/kg doses of soman caused dose- and time-related increases in plasma levels of glucose, corticosterone, norepinephrine, epinephrine, and a depression of insulin. Many of these increases, as well as the severity of toxicity, appear to be inversely related to the hypothalamic acetylcholinesterase levels. The hyperglycemia following the higher doses of soman is likely due to the combined effects of elevated levels of corticosterone, catecholamines, possibly glucagon, and depressed insulin levels. Stress from the toxic effects of soman is likely partially responsible for the endocrine effects since most of the changes observed are consistent with changes in these levels that would be manifested in an animal stress model.
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PMID:Effect of acute soman on selected endocrine parameters and blood glucose in rats. 306 86


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