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Biomedical subjects

H Mehnert

Publications and source records attributed to H Mehnert.

At least 109 records · Page 6Linked to original sources
PubMed1986

Inhibition of muscular glucose uptake by lipid infusion in man.

During a high-dose intravenous infusion of a mixed MCT/LCT-lipid emulsion and a conventional LCT-emulsion respectively, muscle substrate metabolism was investigated using the human forearm technique. With both lipid emulsions, a decrease in fractional muscular glucose extraction was seen, leading to significantly reduced muscular glucose uptake rates. An inverse linear relation between arterial tree fatty acids supply and fractional glucose extraction was seen suggesting that a mechanism according to Randle's glucose fatty acid concept is operating in skeletal muscle in man.

Journal Article↗
PubMed1986

Inhibition of muscular triglyceride lipolysis by ketone bodies: a mechanism for energy-preservation in starvation.

Using the forearm technique, muscle substrate balances were measured in healthy volunteers under the influence of a low dose intraarterial infusion of beta-hydroxybutyrate. The ketone body led to a prompt cessation of muscular release of glycerol and free fatty acids, indicating inhibited muscular triglyceride lipolysis. This finding confirms the concept of substrate regulation of muscle triglyceride lipolysis in vivo.

3-Hydroxybutyric Acid↗
PubMed1986

Influence of bisoprolol on blood glucose, glucosuria, and haemoglobin A1 in noninsulin-dependent diabetics.

In a double-blind crossover study, the influence of bisoprolol and placebo was tested in 20 noninsulin-dependent diabetics with concomitant essential hypertension. A 2-week washout placebo period was followed by two treatment periods of 2 weeks each with 10 mg bisoprolol or placebo. Compared with placebo, bisoprolol did not change blood glucose, haemoglobin A1 (HbA1), and glucosuria. No hypoglycaemia was observed. Serum cholesterol and triglyceride levels remained constant. Systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) were significantly (p less than 0.01) reduced after 2 weeks of bisoprolol therapy, compared with placebo. It was concluded that bisoprolol, in a dose therapeutically effective in essential hypertension, has no influence on carbohydrate and lipid metabolism in noninsulin-dependent patients with diabetes mellitus; and 10 mg bisoprolol is effective for the normalisation of SBP and DBP in mildly hypertensive diabetics. Since bisoprolol was well tolerated in the dosage studied, it can be recommended for noninsulin-dependent diabetics with hypertension.

Adrenergic beta-Antagonists↗
PubMed1986

Angiotensin converting enzyme inhibitors in diabetes: experimental and human experience.

Peripheral glucose metabolism was studied during the influence of elevated systemic kinin levels by either application of exogenous bradykinin (BK) or inhibition of endogenous kinin degradation by angiotensin converting enzyme inhibitors (ACEI). In infusion experiments in streptozotocin-diabetic rats, both BK (0.3 micrograms/min) and ACEI (300 micrograms captopril/100 g) showed a significant reduction of elevated blood glucose levels. In man, non-insulin dependent diabetics (NIDD) and healthy subjects in postoperative (POP) stress were examined. Peripheral insulin-sensitivity and muscular glucose balance were determined using the glucose clamp technique and the forearm technique. In NIDD as well as in POP subjects, impaired peripheral insulin responsiveness, as evaluated by whole body glucose consumption, was improved up to 50% by application of BK (80 micrograms/h i.v.) or ACEI (25 mg captopril p.o.), respectively. This was most probably due to accelerated muscular glucose uptake which was assessed in the same experiment and found to be increased 2- to 3-fold under these conditions. As a molecular basis for the observed effects on muscular glucose uptake, phosphofructokinase was found to be markedly stimulated by BK (8 X 10(-10)mol/l) in the isolated perfused rat heart, suggesting accelerated glycolytic flux. It may be concluded that ACEI increase muscular insulin responsiveness, thus being beneficial in insulin-resistant states as well as in hypertension. This metabolic effect is most probably due to elevated systemic kinin levels. Further investigations are required to evaluate the clinical relevance of these findings.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1986

[Comparative studies of the metabolism of MCT/LCT and LCT emulsions in diabetics].

In 7 moderately overweight non-insulin dependent diabetics with slightly elevated triglyceride levels, disappearance rates of MCT/LCT- und LCT-emulsions were compared. 5 metabolically healthy volunteers served as control. During a 3-hour lipid infusion, serum triglycerides reached a steady state with both emulsions in the healthy controls, whereas in diabetic patients, steady state triglyceride levels were seen only with MCT/LCT. After the end of the lipid infusion, the longest half life value concerning the decline of triglyceride levels was found with LCT in diabetics, while significantly shorter and quite similar half life values were found with LCT in healthy controls and MCT/LCT in diabetics. The shortest half life for serum triglycerides was expectedly found in healthy controls. According to these data, parenteral nutrition with lipids in states of disturbed glucose and lipid metabolism--if necessary--should preferentially be done with MCT/LCT emulsions.

Diabetes Mellitus, Type 2↗
PubMed1985

[Experiences with Reflolux in blood sugar self testing].

As to correctness and accuracy the Reflolux system is comparable to the conventional measurement of blood glucose under laboratory conditions. Its handling is simple and safe so that diabetic patients are able to check their blood sugar reliably by self-control. Skilled patients achieve just as good results as laboratory personnel.

Blood Glucose↗
PubMed1985

[Early diagnosis of autonomic diabetic neuropathy using sensitivity to temperature].

Testing temperature sensitivity thresholds and sensory nerve velocity in 76 type I diabetics and 16 healthy controls gave the following results: In 24 patients with dysfunction of one or more autonomic nervous system functions (histamine test reaction, erectile impotence, gastroparesis, orthostatic hypotension and bladder atonia) temperature sensitivity of the lower limbs, as an early manifestation of distal diabetic neuropathy, was markedly impaired compared with healthy controls as well as patients without autonomic dysfunction (n = 52); sensory nerve velocity (sural nerve) was similar in the two groups; metabolic parameters (blood glucose 1 hour postprandial morning and noon; glucose in 24-h urine, and HbA1a-c) also failed to demonstrate any difference between the two patient groups.

Adolescent↗
PubMed1985

Evidence for a substrate regulation of triglyceride lipolysis in human skeletal muscle.

Glycerol release from the human forearm which is generally used as a semiquantitative index of intramuscular lipolysis was studied under different hormonal influence and substrate supply in healthy volunteers and juvenile diabetics using the forearm technique. Acute insulin deficiency in juvenile diabetics failed stimulating the rate of muscular lipolysis since the rates of glycerol release in normals and diabetics were the same. In addition, in normal volunteers high physiological levels of insulin caused by an intraarterial infusion of the hormone exhibited no effect on the glycerol release from deep forearm tissue. Similarly, an intraarterial infusion of metaproterenol did not accelerate muscular glycerol release in normal man. However, in juvenile diabetics in acute insulin deficiency the same dose of the catecholamine increased the rate of muscular glycerol production. Elevated substrate supply during intravenous infusion of glucose or fructose yielded increased uptake of glucose and fructose into the deep forearm tissue and thereby promptly blocked muscular glycerol release in normal volunteers and in juvenile diabetics. These findings suggest that the rate of lipolysis in muscle tissue is not primarily under the control of hormones but rather by substrate supply.

Adult↗
PubMed1983

Dose-dependent effect of bradykinin on muscular blood flow and glucose uptake in man.

Using the forearm technique, the effect of bradykinin on muscular blood flow and glucose uptake in healthy man in the postabsorptive state (n = 8) was studied at different doses of an intra-arterial infusion of bradykinin (2.5-150 ng/min). The blood flow of the forearm was increased dose-dependently from basal 2.8 +/- 0.3 up to 14.7 +/- 2.8 ml/(100 g X min). At lower bradykinin concentrations (2.5-25 ng/min), muscular glucose uptake was raised parallel to the increased blood flow from basal 0.71 +/- 0.30 to 2.93 +/- 0.50 mumol/(100 g X min). However, at higher doses (50-150 ng/min) glucose uptake was decreased again. Thus, the greatest metabolic effect of bradykinin was seen at a calculated bradykinin concentration of approximately 1 X 10(-9)M in the blood.

Bradykinin↗