The main purpose of this study is to determine the half life of the hormone "ghrelin" in the human body. Other purposes are to investigate the effect of ghrelin on appetite and cardiovascular function.

Ghrelin is a recently described acylated peptide hormone produced by the enteroendocrine cells of the mucosal epithelial layer in the ventricle. Ghrelin is the endogenous ligand for the growth hormone (GH) secretagogue receptor (GHS-R).

Ghrelin stimulates pituitary GH release by binding to the GHS-R at both hypothalamic and pituitary levels.

Several studies show that bolus injections of ghrelin have positive effects on cardiac function in healthy humans as well as in humans with cardiac disease. We investigate the changes in cardiac function during ghrelin infusion in healthy subjects.

The pharmacokinetics of ghrelin is described in few studies only, and we aim to elucidate this aspect further.

Comparisons: In a double blind, placebo controlled, cross over study we investigate the effect of 180 minutes ghrelin infusion on 1. cardiac function (tissue Doppler, stroke-velocity index), 2. vascular tone (a. brachialis dilatation), 3. ghrelin-half-life (acylated and des-acylated) and other pharmacokinetic parameters and 4. effect on appetite.

Inclusion Criteria:

• Healthy
• Male
• BMI < 25 kg/m2
• Non-smoker
• Age < 40 yrs

Exclusion Criteria:

• Any known disease
• Any medication (except OTCs)
• Former malignant disease
• Alcoholism
• Blood donation (with in 6 months)
• Allergy to test medication