Question

Mavis Trippe is a 41 – year-old woman who has worked at the cosmetics counter of the local
department store for many years. Mavis’ colleagues in cosmetics noted that her physical appearance
had change – her features had become coarse, her lower jaw was protruding, and her teeth had
separated. They were concerned that Mavis might have a health problem, and one of the colleagues
volunteered to have a talk with her. Mavis was a little hurt at their observations, but then opened up
and expressed concerns of her own. She disclosed that her menstrual periods had suddenly stopped 5
years ago; that her hat, shoe, and glove size had increased; and that her fingers had enlarged so much
that her rings no longer fit. Every night, she had been getting up several times to urinate. Mavis
decided to see a physician for evaluation of these strange symptoms.
Physical examination revealed a woman with coarse facial features, a prominent jaw, and large hands
and feet. Her blood pressure was elevated at 170/110. The results of laboratory studies are
summarized in Table 1.
Table 1 Mavis Trippe’s Laboratory Values
Glucose, fasting 250 mg/dl (normal, 70-100 mg/dl)
Growth hormone, fasting 90 ng/mL (normal, 2-6 ng/mL)
IGF-I Elevated
FSH Decreased
TSH Normal
T 4 Normal
Prolactin Elevated
During the administration of glucose in a glucose tolerance test, Mavis’ growth hormone levels
remained elevated. Magnetic resonance imaging (MRI) of Mavis’ brain showed a large intrasellar mass
that was pushing upward on the roof of the sella turcica. The physician diagnosed her with acromegaly,
caused by a pituitary adenoma that was secreting growth hormone.
Trans sphenoidal surgery was performed to remove a large pituitary adenoma. Post operatively, Mavis’
growth hormone and blood glucose levels fell into the normal range. Although her menstrual cycles did
not return, the physicians told Mavis that, over time, should could expect improvement in her facial
features and reduction in the swelling of her feet and hands.

Construct a negative feedback diagram illustrating the relationship between the Anterior
Pituitary gland, Hypothalamus, and Target tissues associated with both Acromegaly and Blood
Glucose regulation.

Answer 1

in the above mentioned flow chart + indicate stimulates the release

- indicates suppress the release

GHRH stimulates the production of growth hormone

growth hormone exerts its effects through insulin like growth factor-1 which is produced in liver

functions of growth hormone :

• increases insulin production
• reduces cellular uptake of glucose
• promotes bone growth
• cell proliferation and differentiation
• stimulates lipolysis