Abstract
The main target of action of glucagon-like peptide-1 (GLP-1) is the islet, where the
hormone stimulates insulin secretion, promotes beta cell proliferation and neogenesis,
and inhibits glucagon secretion. However, GLP-1 receptors are also expressed outside
the islets, increasing the likelihood that GLP-1 also plays a role in other organs.
These functions are mainly the inhibition of gastric emptying, gastric acid secretion
and exocrine pancreatic secretion, indicating that the hormone acts as an enterogastrone
- a hormone released from the distal portion of the small intestine that inhibits
proximal gastrointestinal events. Another important action of GLP-1 is to induce satiety.
Other effects of the hormone include cardioprotection, neuroprotection, induction
of learning and memory, stimulation of afferent, sensory nerves, stimulation of surfactant
production in the lung, dilatation of pulmonary vessels, induction of diuresis, and
also under some conditions, induction of antidiabetic actions unrelated to islet function.
Thus, GLP-1 clearly has several manifestations of activity. The physiological relevance
of these actions and their contribution to the overall antidiabetic action of GLP-1
when used in treatment of type 2 diabetes remains to be established.
Key words
GLP-1 - Extra-islet - Gastric emptying - gastric acid secretion - Pancreatic secretion
- Cardiac function - Sensory nerves
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Dr B. Ahrén
Department of Medicine
B11 BMC · SE-221 84 Lund · Sweden
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Email: Bo.Ahren@med.lu.se
