system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which one of the following is the primary site of production of gastrin
assistant
The correct answer is  Gastrin secreted by
-        G cells in the antral and duodenal mucosa.
-        TG cells in stomach and ileum
-        Pituitary, brain and nerves
-        Pancreatic islets in the fetus