Pituitary tumors containing cholecystokinin

Area of Science:

• Endocrinology
• Neuroscience
• Molecular Biology

Background:

• Cholecystokinin (CCK) is a peptide hormone found in the gastrointestinal tract and brain.
• The presence and function of CCK in the human pituitary gland, particularly in pituitary tumors, remain largely uncharacterized.

Purpose of the Study:

• To investigate the presence and levels of cholecystokinin (CCK) in various pituitary tumors.
• To characterize the molecular form of CCK produced by these tumors.

Main Methods:

• Analysis of cholecystokinin concentrations in pituitary tumor tissue samples from 87 patients.
• Comparison of CCK levels and peptide characteristics (size, sulfation) between normal pituitary glands and tumor tissues.
• Categorization of tumors based on clinical diagnosis (acromegaly, Cushing's disease, Nelson's syndrome, prolactinoma, inactive adenomas) and ACTH content.

Main Results:

• Elevated cholecystokinin (CCK) levels were detected in five adenomas associated with Nelson's syndrome, with extremely high concentrations in two cases.
• Moderately increased CCK concentrations were observed in adenomas from 12 additional patients, including those with Cushing's disease and acromegaly.
• CCK peptides isolated from tumors were smaller and less sulfated compared to CCK from normal pituitary glands.

Conclusions:

• ACTH-producing pituitary cells are capable of producing cholecystokinin (CCK).
• Pituitary tumors, particularly those associated with Nelson's syndrome and Cushing's disease, can exhibit altered forms of CCK production.
• This suggests a potential role for CCK in the pathophysiology of certain pituitary adenomas.