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Biomedical subjects

T Sane

Publications and source records attributed to T Sane.

At least 55 records · Page 3Linked to original sources

Effects of orchiectomy and polyestradiol phosphate therapy on serum lipoprotein lipids and glucose tolerance in prostatic cancer patients.

In 17 prostatic cancer patients, changes in the plasma lipoprotein pattern, including high density lipoprotein (HDL) subfractions, and in glucose tolerance were compared after 6 months on parenteral polyestradiol phosphate (PEP; Estradurin, 80 or 160 mg/month) with the respective changes in orchiectomized patients. In the estrogen group there was no change in the total serum cholesterol level, whereas in the orchiectomy group an increase of 10% was observed. Estrogen therapy resulted in a significant increase of serum HDL (11%) and HDL2 cholesterol (26%) levels; in the orchiectomy group these fractions remained unchanged. Estrogen therapy induced a significant decrease in total serum triglycerides (24%) and in low density lipoprotein triglycerides (27%); in the orchiectomy group reverse changes were observed. PEP treatment caused changes in the serum lipoprotein pattern, which apparently decreases the risk of atherosclerosis.

Aged↗

Insulin inhibition of overnight glucose production and gluconeogenesis from lactate in NIDDM.

Increased gluconeogenesis contributes to fasting hyperglycemia in non-insulin-dependent diabetes mellitus (NIDDM). We examined whether insulin inhibits gluconeogenesis from lactate by altering the fate of lactate and/or by reducing lactate flux. Seven patients with NIDDM (age 51 +/- 4 yr, body mass index 28 +/- 2 kg/m2) were studied before and 3 wk after achieving normoglycemia with evening insulin therapy. Basal glucose production (Ra) and utilization were measured overnight [( 3-3H]glucose infusion from 9 P.M. to 8 A.M.) and lactate turnover and conversion to glucose between 4 and 8 A.M. [( U-14C]lactate infusion) before and after insulin therapy. During insulin therapy, fasting plasma glucose decreased from 188 +/- 13 to 99 +/- 7 mg/dl (P less than 0.001) due to inhibition of glucose Ra from 3.0 +/- 0.1 to 2.2 +/- 0.1 mumol.kg-1.min-1 (P less than 0.005). Plasma free insulin increased from 6 +/- 1 to 11 +/- 1 microU/ml (P less than 0.005). Plasma lactate concentrations (1.1 +/- 0.2 vs. 1.0 +/- 0.1 mmol/l before vs. after insulin therapy) and the lactate turnover rate (15.6 +/- 0.9 vs. 14.2 +/- 0.8 mumol.kg.min) remained unchanged, whereas the amount of glucose formed from lactate decreased from 2.0 +/- 0.1 to 1.4 +/- 0.2 mumol.kg-1.min-1 (P less than 0.02) and the percent of lactate turnover converted to glucose decreased from 26 +/- 1 to 20 +/- 2% (P less than 0.05). We conclude that insulin inhibits overnight glucose Ra from lactate by decreasing the proportion of lactate diverted towards gluconeogenesis rather than by altering lactate availability or total flux.

Adult↗

Prolonged exercise increases serum insulin-like growth factor-binding protein concentrations.

We studied the response of serum 34K insulin-like growth factor-binding protein (IGF-BP) to two types of prolonged exercise. In the first study, 11 normal men performed cycle ergometer exercise, after an overnight fast, for 3 h at the intensity corresponding to 45-50% of their maximal aerobic power. After the exercise, the mean serum IGF-BP concentration was 4.9-fold higher than the baseline level (P less than 0.01), while the IGF-I concentration did not change. Resting for the same time period resulted in a 38% fall in the serum IGF-BP level (P less than 0.01). In the second study, 10 normal men and 8 type 1 diabetic men exercised, on the average, for 7.5 h in a 75-km cross-country ski race. The mean serum IGF-BP concentration increased 5.4-fold (P less than 0.01) in the normal men and 4.2-fold (P less than 0.01) in the diabetic men. The serum IGF-I concentration decreased by 19% and 21% in the normal and diabetic men, respectively (P less than 0.01). After completion of the ski race, the serum insulin and IGF-BP levels (r = -0.70; P less than 0.05), and serum IGF-I and IGF-BP levels (r = -0.72; P less than 0.05) were inversely correlated in the normal men. No such correlations were found in the diabetic men. We conclude that 1) long term exercise increases serum IGF-BP concentrations in both normal and type 1 diabetic men; and 2) the increases are inversely related to alterations in serum IGF-I and insulin concentrations in normal men. These data suggest that IGF-BP may be involved in regulation of the biological action of IGF-I during prolonged exercise.

Adult↗

Bedtime insulin for suppression of overnight free-fatty acid, blood glucose, and glucose production in NIDDM.

We studied the clinical effectiveness and mechanism underlying the glucose-lowering effect of evening insulin therapy. Nocturnal profiles of blood glucose, plasma free fatty acid (FFA), glycerol, and lactate and overnight glucose kinetics [( 3-3H] glucose infusion) were measured in 15 non-insulin-dependent diabetic (NIDDM) patients with a relative body weight of 128 +/-4% who were poorly controlled with oral therapy alone. The patients were studied before and 2 wk and 3 mo after bedtime insulin (23 +/- 3 IU) was given in addition to oral therapy. An early-morning rise in blood glucose (greater than 31 mg/dl = 1.5 mM) was present in two-thirds of the patients and was associated with an overnight rise in plasma FFA and an increase in glucose production (Ra) during the early-morning hours (change 0.42 +/- 0.10 mg.kg-1.min-1, P less than .05, between 0300 and 0800). The overnight mean levels of blood glucose, plasma FFA, and serum insulin averaged 212 +/- 9 vs. 137 +/- 11 vs. 133 +/- 11 mg/dl (P less than .001), 674 +/- 61 vs. 491 +/- 57 vs. 484 +/- 36 microM (P less than 0.01) and 12.7 +/- 1.6 vs. 18.1 +/- 2.2 vs. 20.7 +/- 2.4 microU/L (P less than .01) before and 2 wk and 3 mo after the combination therapy. The decrements in overnight glucose and FFA levels after 2 wk of bedtime insulin therapy were closely correlated (r = .86, (P less than .001). The nocturnal profile of plasma lactate was similar before and during bedtime insulin therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗

Stimulation of prostacyclin synthesis by physical exercise in type I diabetes.

We examined the effect of short- and long-term exercise on prostacyclin (prostaglandin I2 [PGI2]) and thromboxane A2 (TXA2) synthesis in type I (insulin-dependent) diabetic patients and healthy control subjects. PGI2 synthesis was assessed by determining the urinary excretion of 6-keto-PGF1 alpha and 2,3-dinor-6-keto-PGF1 alpha and TX synthesis by measuring TXB2 in serum and urine. In the resting state, prostanoid excretion and concentrations were similar in diabetic and control subjects. During 40 min of ergometric cycling exercise, the urinary excretion of 6-keto-PGF1 alpha (a hydration product of vasodilatory PGI2) increased 5.8-fold more in the 12 control subjects than in the 15 diabetic patients (P less than .02). Serum TXB2 concentration rose similarly in diabetic patients and control subjects (P less than .05). During a 75-km competitive cross-country ski race (7 h, 30 min), urinary excretion of 6-keto-PGF1 alpha rose 1.9-fold in 7 diabetic (P less than .05) and 3.3-fold in 10 control (P less than .001) subjects, whereas urinary dinor excretion, reflecting vascular PGI2 synthesis more closely, increased only in the control subjects (P less than .01). Urinary TXB2 excretion remained unchanged in both groups during long-term exercise. These data suggest that diabetic patients have normal PGI2 and TXA2 synthesis in the resting state but diminished PGI2 response to both acute and prolonged exercise.

6-Ketoprostaglandin F1 alpha↗

The adjustment of diet and insulin dose during long-term endurance exercise in type 1 (insulin-dependent) diabetic men.

We examined in 2 consecutive years the effect of a 75-km (greater than 7 h) cross country skiing on dietary and insulin requirements and glycaemic control in 9 Type 1 (insulin-dependent) diabetic patients. In the first year, the patients were hyperglycaemic (20.9 +/- 1.8 mmol/l) before the race due to excessive carbohydrate loading (65 g) and reduction (by 58%) of short-acting insulin for breakfast. In the second year, breakfast included less carbohydrate (40 g) and more protein, and the morning short-acting insulin was reduced by 35%. With this adjustment of therapy the pre-exercise hyperglycaemia was less (p less than 0.05). The morning intermediate-acting insulin was reduced by 28 and 38% in consecutive years. During both races carbohydrate intake approximated 40 g/h, and blood glucose was maintained at near normal levels after 33 km of skiing. Hypoglycaemia did not occur during exercise, but one patient had symptomatic hypoglycaemia after finishing the second race. The day after exercise insulin sensitivity was increased in all four patients studied. Insulin treated patients can perform strenuous long-term exercise and maintain near normoglycaemia with a proper adjustment of therapy. Augmented insulin sensitivity may contribute to post-exercise hypoglycaemia.

Adult↗

Alcohol-induced changes in serum lipoproteins and in their metabolism.

The effects of alcohol intake on serum lipids and lipoproteins depend on the dose and mode of alcohol intake, individual susceptibility, genetic variables, and dietary factors. Therefore the changes of lipoprotein pattern are different among moderate and heavy drinkers. Moderate intake of alcohol increases the concentrations of apolipoproteins (apo) AI, apo AII, and high-density lipoprotein subfraction (HDL3) in plasma without any effects on other lipoproteins. If alcohol intake exceeds 60 to 80 gm per day, the synthesis of very low-density lipoprotein (VLDL) particles is stimulated. Even short-term use of alcohol stimulates lipoprotein lipase (LPL) activity in adipose tissue, and consequently the concentration of VLDL in plasma stays normal or is even subnormal. If alcohol intake continues in excessive amounts, the increased transport rate of VLDL particles as a result of high LPL activity results in the up regulation of HDL2. This is clearly evident in chronic alcoholics. Low or subnormal low-density lipoprotein (LDL) levels are another characteristic of the lipoprotein pattern in chronic alcoholics. The increase of HDL (HDL2) and reduction of LDL levels could well explain the reduced risk of coronary heart disease in chronic alcoholics, whereas the causal factors remain open among moderate drinkers.

Alcoholism↗

DNA polymorphisms of apolipoprotein A-I/C-III and insulin genes in familial hypertriglyceridemia and coronary heart disease.

Two DNA polymorphisms adjacent to the apolipoprotein A-I/C-III and insulin genes have been suggested to be associated with hypertriglyceridemia and increased risk of coronary heart disease. Using cloned apolipoprotein A-I and insulin gene probes, we determined the genotypes of 39 subjects from six different kindreds with familial clustering of hypertriglyceridemia, 20 additional unrelated subjects with hypertriglyceridemia, 39 patients with angiographically confirmed coronary heart disease (CHD) and 61 normolipemic control subjects. The S2 allele bearing an additional SstI restriction site in the apo A-I/C-III complex was found in 16% of healthy controls, 23% of patients with CHD and 62% (P less than 0.001 when compared to controls) of unrelated subjects with hypertriglyceridemia. Among CHD patients the S2 allele was present in 6 out of 14 hypertriglyceridemic patients but only 3 out of 25 normotriglyceridemic patients (P less than 0.05). The S2 allele was present in 64% of subjects from kindreds with hypertriglyceridemia but this allele did not determine the occurrence of hyperlipidemia. The frequencies of the large size or U allele of the polymorphic DNA region flanking the 5' end of the insulin gene in CHD patients (33%) and in controls (24%) were not significantly different. Neither of the polymorphisms studied was associated with changes in serum LDL or HDL cholesterol levels in patients with CHD or unrelated subjects with hypertriglyceridemia. The data suggest that, at least in the Finnish population, the S2 allele of the apolipoprotein A-I/C-III gene complex may serve as a genetic marker for hypertriglyceridemia, whereas both DNA polymorphisms studied are probably useless in determining individual risks of atherosclerosis.

Adult↗

Very low density lipoprotein triglyceride kinetics during hepatic lipase suppression by estrogen. Studies on the physiological role of hepatic endothelial lipase.

The exact role of the heparin-releasable hepatic endothelial lipase has remained controversial. It has been suggested that it acts in concert with lipoprotein lipase in the step-wise delipidation of triglyceride-rich lipoproteins. On the other hand, there is evidence indicating that high density lipoprotein2 is the preferred substrate for hepatic lipase. Here, it is shown that a moderate (27%) suppression of hepatic lipase activity by estrogen did not impair removal of 3H-labeled very low density lipoproteins (VLDL) triglycerides, suggesting that this enzyme is not a major regulator of VLDL catabolism under physiological circumstances.

Endothelium↗

Accelerated turnover of very low density lipoprotein triglycerides in chronic alcohol users. A possible mechanism for the up-regulation of high density lipoprotein by ethanol.

The concentration of high density lipoproteins (HDL) is related to the catabolism of triglyceride-rich lipoproteins. In order to elucidate the mechanisms by which alcohol increases plasma HDL levels we measured the turnover kinetics of very low density lipoprotein (VLDL) triglycerides in 10 alcoholic men without liver disease and in nonalcoholic control men matched for age, weight and plasma VLDL triglyceride level. The study was repeated in the alcoholics after a 2-week abstinence period. The alcoholic men had elevated HDL cholesterol but reduced low density lipoprotein (LDL) cholesterol as compared to the controls. The fractional catabolic rate and the total turnover (production) rate of VLDL triglycerides were both significantly increased (P less than 0.05) in the alcoholic men before abstinence. After withdrawal of alcohol both the synthetic rate and the catabolic rate of VLDL triglycerides returned to normal and the HDL (HDL2 and HDL3) cholesterol fell. The per cent decrease in HDL2 cholesterol during abstinence was positively correlated to the respective fall of VLDL triglyceride fractional catabolic rate (r = +0.51). The results suggest that the absence of hypertriglyceridemia and the elevated levels of HDL in regular alcohol users may be partly based on increased metabolic clearance of VLDL particles and on subsequent accelerated transfer of the VLDL surface components to HDL.

Adult↗