Endotoxin & Cytokines. Do Protein Loss and Metabolic Effects Depend on Central Nervous System (CNS) Activation of Stress Hormones or on Local Mechanisms in Muscle and Fat?

Aarhus University Hospital

Status: Completed

Conditions: Inflammation; Glucose Metabolism Disorders

Treatments: Biological: Endotoxin; Biological: TNF-alpha

Study type: Interventional

Funder types: Other

Identifiers

NCT01452958

2010/0604

Details and patient eligibility

About

Main objective :

The purpose of this study is to prove that the effects of bacterial endotoxin and cytokine TNF-α, on protein loss, fatty acid release, and glucose metabolism depend on two mechanisms:

1. Direct local effects in muscle tissue.
2. Activation of the hypothalamo-pituitary axis and a stress-hormone response

Study protocols:

1. Acute metabolic effects of TNF-α(Beromun, Boehringer-Ingelheim Germany) vs placebo perfused into the femoral artery of the leg in 8 healthy subjects.

2. Acute metabolic effects of

   • placebo(saline)
   • endotoxin(US standard reference E.Coli, endotoxin)
   • TNF-α(Beromun, Boehringer-Ingelheim Germany) given systemically
   • in 8 patients with hypopituitarism(to block stress hormone release) and in 8 healthy subjects all studied thrice.

Full description

PURPOSE:

Knowledge about the effects of bacterial endotoxin and cytokines (and inflammation in general) in humans on protein, glucose and lipid metabolism and intracellular signalling in muscle and fat is sporadic and it is uncertain whether endotoxin and cytokines act directly in fat and muscle tissue or indirectly via central nervous system (CNS) mediated stress hormone release.

The investigators hypothesize that the metabolic effects of endotoxin and cytokine TNF-α, including protein loss, fatty acid release and decreased glucose uptake depend on two mechanisms:

1. Direct local effects in muscle tissue (Study protocol 1)
2. Activation of the hypothalamo-pituitary axis and generalized stress hormone response (Study protocol 2)

METHODOLOGY:

Study protocol 1:

Acute metabolic effects of TNF-α (Beromun, Boehringer-Ingelheim, Germany) versus placebo perfused into the femoral artery of the leg in 8 healthy subjects, studied once. Femoral vein sampling allows assessment of local metabolic events in the leg. The vessels were cannulated using the Seldinger technique. Each study comprises a 3 hour basal period and a 3 hour Hyperinsulinemic-Euglycemic Clamp. Muscle biopsies were obtained simultaneously from both lateral vastus muscles.

Study protocol 2:

Acute metabolic effects of (i)placebo (saline), (ii)endotoxin (US standard reference E.Coli, endotoxin) and (iii)TNF-α (Beromun, Boehringer-Ingelheim, Germany) given systemically intravenously (i.v.) in 8 patients with hypopituitarism (to block stress hormone release) and in 8 healthy subjects all studied thrice. Every study comprises a 4 hour basal period and a 2 hour Hyperinsulinemic-Euglycemic Clamp. Muscle and fat biopsies were obtained.

Study protocol 1 and Study protocol 2:

Assays: Mass spectrometry (15N-phenylalanine, 13C-urea), 3H-glucose, 3H-palmitate quantification, hormone and metabolite analysis, cytokine assays, intracellular signaling.

Enrollment: 24 patients

Sex: Male

Ages: 18 to 70 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria 1. group:

• Male
• 19 < BMI < 28
• 18 ≤ Age ≤ 50
• Healthy

Inclusion Criteria 2. group:

• Male
• 20 < BMI < 30
• Age > 25
• Healthy

Exclusion Criteria:

• Diseases
• Allergy

Trial design

24 participants in 2 patient groups

TNF-α

Experimental group

Description:

Beromun, Boehringer-Ingelheim, Germany

Treatment:

Biological: TNF-alpha

Endotoxin

Experimental group

Treatment:

Biological: Endotoxin