Potential sources of growth hormone excess within the growth hormone axis

(A) Normal axis
(B) Increased hypothalamic GHRH secretion
(C) Increased pituitary GH secretion
(D) Decreased SS tone

SS: somatostatin; GHRH: growth hormone-releasing hormone; GH: growth hormone; IGF-1: insulin-like growth factor-1.

Courtesy of Erica A Eugster, MD and Ora H Pescovitz, MD.

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