Page 681 - Basic _ Clinical Pharmacology ( PDFDrive )

SECTION VII ENDOCRINE DRUGS

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Hypothalamic & Pituitary

Hormones

Roger K. Long, MD, & Hakan Cakmak, MD

C ASE STUD Y

A 4-year-old boy (height 90 cm, –3 standard deviations Laboratory evaluations demonstrate growth hormone
[SD]; weight 14.5 kg, approximately 15th percentile) (GH) deficiency and a delayed bone age of 18 months.
presents with short stature. Review of the past history The patient is started on replacement with recombinant
and growth chart demonstrates normal birth weight and human GH at a dose of 40 mcg/kg per day subcutaneously.
birth length, but a progressive decrease in height per- After 1 year of treatment, his height velocity has increased
centiles relative to age-matched normal ranges starting from 5 cm/y to 11 cm/y. How does GH stimulate growth
at 6 months of age, and orthostasis with febrile illnesses. in children? What other hormone deficiencies are sug-
Physical examination demonstrates short stature and gested by the patient’s history and physical examination?
mild generalized obesity. Genital examination reveals What other hormone replacements is this patient likely
descended but small testes and a phallic length of –2 SD. to require?

The control of metabolism, growth, and reproduction is medi- and blood vessels, including a portal venous system that drains
ated by a combination of neural and endocrine systems located the hypothalamus and perfuses the anterior pituitary. The portal
in the hypothalamus and pituitary gland. The pituitary weighs venous system carries small regulatory hormones (Figure 37–1,
about 0.6 g and rests at the base of the brain in the bony sella Table 37–1) from the hypothalamus to the anterior pituitary.
turcica near the optic chiasm and the cavernous sinuses. The The posterior lobe hormones are synthesized in the hypothala-
pituitary consists of an anterior lobe (adenohypophysis) and a mus and transported via the neurosecretory fibers in the stalk of
posterior lobe (neurohypophysis) (Figure 37–1). It is connected the pituitary to the posterior lobe; from there they are released
to the overlying hypothalamus by a stalk of neurosecretory fibers into the circulation.

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