Treatment Options for Pituitary Tumor / Pituitary Function Testing
Pituitary Tumor & Neuroendocrine Disorders
- Pituitary hormones are released in pulses, levels fluctuate during the
day, and the release of one hormone directly affects the release of others.
For these reasons, a single blood test often is not sufficient to determine
the nature and extent of a specific type of pituitary deficiency. Effective
assessment tests include the following:
Cortrosyn
Stimulation Test
- Adrenocorticotropic
hormone (ACTH) is injected to stimulate the adrenal glands and blood cortisol
level is checked 60 minutes later.
- When pituitary
disease impairs ACTH production, the adrenal glands lose their capacity to
secrete cortisol in response to stimulation.
Metyrapone
Test
- This test also
assesses pituitary ACTH hormones. Twelve tablets (3 grams) of metyrapone are
given to the patient at bedtime and blood is drawn the following morning to
check ACTH levels.
- Since
metyrapone blocks adrenal hormone production, normal individuals respond by
producing large amounts of ACTH. Lack of response indicates pituitary disease
affecting ACTH production.
Insulin Tolerance
Test
- In this test,
insulin is injected to lower blood sugars (hypoglycemia).
- The normal
response to hypoglycemia is release of ACTH and growth hormone (GH), which
counteracts low blood sugars. Patients deficient in GH and ACTH fail show no
hormonal response to hypoglycemia.
|
|