The objective of the study is to delineate the glucagonotropic signal exerted by selected amino acids in human subjects as well as the metabolic clearance rate of these amino acids after intravenous infusion

After being informed about the study and the potential risks, each participant giving written informed consent will participate in six experimental days. The glucagonotropic effect and metabolic clearance of selected amino acids and saline (placebo), respectively, will be evaluated in 12 healthy individuals. After screening, each participant will undergo 6 double-blinded experimental days performed in randomized order. The experimental days will each last 75 minutes. The amino acids selected for the experiment are glutamine, arginine, alanine, leucine and proline.

Inclusion Criteria:

• normal fasting plasma glucose and glycated hemoglobin (HbA1c) < 42 mmol/mol
• body mass index (BMI) between 18.5 and 25 kg/m2
• Hemoglobin > 8.3 mmol/L
• Age between 20 and 65 years
• oral and written informed consent

Exclusion Criteria:

• Diabetes
• first-degree relatives with diabetes
• fasting plasma triglycerides indicating dyslipidemia (> 2 mmol/L)
• nephropathy (eGFR < 60 ml/min) and/or microalbuminuria (albumine/creatinine ratio > 30 microgram/mg)
• liver disease and/or ALT and/or AST levels > 2 x upper normal reference limits.
• signs of liver fibrosis and/or steatosis evaluated by transient elastography (CAP > 238 dB/min) and/or kPa > 6.0) and/or FIB-4 index > 1.45
• regular use of prescription medication
• use of dietary protein supplementation
• any condition the investigator feels would interfere with trial completion

All published data will be made available to other researchers upon reasonable request