ENDOCRINOLOGY“Pituitary hormone regulation

and presentation of pituitary disease”

Richard Ross

Lecture outline

1.Review the anatomy of the hypothalamus and pituitary

2.Describe the regulation of pituitary hormones

3.Describe presentation of pituitary disease

Pituitary Anatomy

Pituitary

Pituitary Anatomy

Pituitary

Pituitary Coronal Section

The anterior pituitary has no arterial blood supply but receives blood through a portal venous circulation from the hypothalamus

Anatomy: Portal Circulation

Discovery of hypothalamic hormones

One Million pig & 50 tons of sheep

hypothalami

Two humans

TRH 1969

GnRH 1971

SMS 1973

CRH 1981

GHRH 1982

Pituitary – thyroid axis

TRH

TSHT4 & T3

-

-Hypothalamus

Pituitary

Thyroid

SPERMTESTOSTERONE

PITUITARY

HYPOTHALAMUS

TESTOSTERONE+

FSHLH

SHBG

GnRH

Pituitary Gonadal Axis

HPA Axis

Hypothalamus

Pituitary

Adrenal

ACTHCortisol

GH / IGF-I AXIS

GHRH

GHIGF-I

+

-Hypothalamus

Pituitary

Liver

SMS-

- ve

SUMMARYRegulation of pituitary hormones

Hypothalamus

• GHRH & SMS• GnRH• CRH• TRH• Dopamine

Pituitary

• GH• LH & FSH• ACTH• TSH• Prolactin

Presentation of pituitary disease

Diseases of the pituitary

• Benign pituitary adenoma• Craniopharygioma• Trauma• Apoplexy / Sheehans• Sarcoid / TB

Large pituitary tumour

Craniopharygioma

Tumours cause:1. Pressure on local structure e.g. optic nerves

– Bitemporal hemianopia

2. Pressure on normal pituitary– hypopituitarism

3. Functioning tumour – Prolactinoma– Acromegaly– Cushing’s disease

Presentation: 3 vital points

1. Pressure on local structures

Measuring the visual fields with a red pin

Bitemporal hemianopia

Functioning Pituitary Tumour

• Prolactinoma• Acromegaly and Gigantism• Cushing’s Disease

Prolactin microadenoma

Tumour

Carotid

Pituitarystalk

OpticChiasm

Galactorrhoea in a prolactinoma

Prolactinomas

• More common in women• Present with galactorrhoea / amenorrhoea

/ infertility• Loss of libido• Visual field defect

• Treatment dopamine agonist eg Cabergoline or bromocriptine.

Harvey Cushing

Causes of Cushing’s syndrome

Patients with a pituitary tumour:1.Is it pressing on optic chiasm2.Are they hypopituitary3.Do they have a functioning tumour

Summary