The Role of Secretin on the Energy Homeostasis

Secretin was - as the first hormone - identified in 19021, but was not isolated until the 1960s. Secretin is produced in and secreted form small intestinal S cells. In the 1970s, the primary endocrine effects of secretin were unequivocally confirmed, namely potentiation of bicarbonate and pepsin secretion from the pancreas as well as stimulation of bile production in the liver. In the 1990s, the biosynthesis of secretin was delineated and its receptor was discovered. In the 2000s the pancreatic regulation of intestinal pH was shown to be secretin-mediated. As of last year, new insight into the function of secretin was brought about as rodent studies showed secretin to possess potential body weight-regulating effects. In these studies, secretin was shown to increase non-shivering thermogenesis in brown adipose tissue (BAT), decrease meal size and promote meal discontinuation.

The primary aim of this study is to evaluate the effect of a 5-hour intravenous infusion with the naturally occurring hormone secretin on ad libitum food intake (primary endpoint) compared to a double-blinded placebo (isotonic saline) infusion in 25 healthy young males.

Inclusion criteria

• Age between 18 and 75 years
• Body mass index between 18.5 and 27.5 kg/m2
• Informed consent
• Body weight above 50 kg

Exclusion criteria

• Anaemia (blood haemoglobin below normal range)
• Known liver disease and/or alanine aminotransferase and/or aspartate transaminase > 2 times upper normal values
• Nephropathy (serum creatinine above normal range and/or albuminuria)
• Clinically significant kidney function impairment or other laboratory findings leading to the diagnosis of clinically relevant disorders (thyroid dysfunction, anaemia etc)
• Any physical or psychological condition that the investigators feel would interfere with trial participation