A Study of Intracellular Signaling in Muscle and Fat Cells During Ketosis

The Role of ATGL and G0/G1 Switch Gene Complex in Lipopolysaccaride (LPS) Induced Ketosis - a Controlled, Randomised, Clinical Experimental Study

Hypothesis To define whether stimulation of ATGL and suppression of G0/G1 switch gene occur in the initial phases of diabetic ketoacidosis and thus can be identified as the primary mechanisms behind this life threatening condition. Make a human model for studying ketoacidosis. The investigators plan to reduce in their regular insulin over night. In the morning we administer endotoxin, which together with a relative lack of insulin will initiate ketogenesis - a state of ketoacidosis. On another occasion strict glycemic control is imposed by means of intravenous insulin. The testing is done two separate days with at least 3 weeks in between and patients are admitted to hospital the evening before the day of testing. The investigators use isotopic tracers to determine metabolic fluxes and analyse fat (ATGL, G0/G1 switch gene) and muscle biopsies.

LPS is endotoxin from gram negative bacteria. It is used scientifically to mimic infection lasting 4-8 hours.

Insulin signaling expressed as a CHANGE in phosphorylation of intracellular target proteins and CHANGE in mRNA expression of target genes in muscle- and fat-tissue.

Change in phosphorylation of target proteins and messenger RNA (mRNA) expression of target genes assessed with western blotting technique.

Muscle and fat biopsies obtained on each study day (arm): t1= 6.45 (-75min) am t2=11.15 (195min) am t3= 12.30 pm (270min)

Muscle and fat at t1 and t2. Muscle biopsy at t3. Intracellular markers are assessed by western blotting.

Muscle and fat biopsies obtained on each study day (arm): t1= 6.45 am (-75min) t2=11.15 (195min) am t3= 12.30 pm (270min)

Change in glucose, fat and protein metabolism assessed by tracer kinetics on every study day (specific times below) and by indirect calorimetry. [3H 3]Glucose tracer from t=0 - 360min. Palmitic acid tracer from t=165min - 360min. Urea tracer from 0min - 240min. amino acid tracer from 60 min - 360 min.

Measurement of immune response to endotoxin and hypoinsulinaemia. Estimating the whole body stress during ketoacidosis and pre ketoacidosis.

Inclusion Criteria: Diabetes type 1 19 < BMI < 26 minimal or negative C-peptide written consent Exclusion Criteria: Severe comorbidity regular medication apart from insulin

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