SBA — Single Best Answer · Review
Question 513
Endocrinology → General
Classification
Question
SSBAQuestion Header
Which metabolic change provides the physiological basis for provoking growth hormone secretion during dynamic pituitary testing?
Question Stem
Select the single best answer.
Options
A
A fall in blood glucose
B
A rise in blood glucose
C
An increase in circulating free fatty acids
D
An increase in cortisol
E
Administration of medroxyprogesterone
Explanation
Growth hormone secretion increases when blood glucose falls. This response provides the physiological basis for using hypoglycaemia in assessment of pituitary growth hormone reserve. Glucose, free fatty acids, cortisol and medroxyprogesterone reduce growth hormone secretion.
Option Validity
B) A rise in blood glucose suppresses rather than provokes growth hormone secretion.
C) Increased circulating free fatty acids reduce growth hormone secretion.
D) Cortisol reduces growth hormone secretion.
E) Medroxyprogesterone reduces growth hormone secretion rather than providing the provocative stimulus described.
Further Reading
Saxena, MRCOG-1 Basic Sciences, Endocrinology: Growth Hormone.