Introduction

This is an information website for patients and healthcare professionals.  Choose the information leaflet you require either by topic or on the A to Z scheme.  You can then print out the leaflet(s) of your choice.  Hyperlinks to other official websites of endocrine information and to patient information helplines are also provided for your convenience.  If you want more information on the local services, clinics, staff, etc, press Endocrine Services.   Diabetes mellitus is not included on the website as we have a separate website and to reach this press DARTS.


ENDOCRINE SYSTEM

It is a body wide system involving various endocrine glands and the effects of the hormones they produce.

ENDOCRINE GLAND

It is a structure, made of special cells that release hormone into the blood stream.

HORMONE

It is a chemical messenger produced by the endocrine glands. It circulates in the blood and has effects on the target cells of the different part of the body away from the site of production.

PITUITARY GLAND

It is a small pea size gland situated in a hollow bony pouch, at the base of the brain, at the back of the bridge of the nose. It is the master gland of the endocrine system and controls the functions of most of the other endocrine glands.

HYPOTHALAMUS

It is a part of the brain just above the pituitary gland, which control the functions of the pituitary gland.

WHAT CAN GO WRONG WITH THE PITUITARY GLAND?

1. Hormone production from the pituitary gland can become either excessive or reduced. It can have different effects on the body and can lead to different disease conditions depending on the type of the hormone involved.
2. An abnormal growth (adenoma) can develop from the pituitary gland, which might or might not produce any hormones. It usually grows very slowly and does not spread elsewhere. The pituitary gland sits in a very limited space and is surrounded by very important structures. Therefore, any enlargement of the growth can have pressure effects on the pituitary gland itself and also to the surrounding area. This can result in disturbed hormone production with subsequent effects on your body. Local pressure effects on the surrounding can also cause headache and disturbed vision.

GENERAL RULES

The amount and the pattern of the hormone production varies throughout the day and may be different from day to day depending on the surrounding situation, stress, other medication and timing of the part of the cycle in female.
Sometimes, associated medical conditions, chest infection strokes, cancer etc can cause temporary abnormal production of hormones.

DIFFERENT HORMONES PRODUCED FROM THE HYPOTHALAMUS

Corticotrophin Releasing Hormone CRF

This hormone has effect on the pituitary and controls the production of ACTH (Please see below) from the pituitary.

Growth Hormone Releasing Hormone GHRH

It acts to release Growth Hormone from the pituitary.

Gonadotrophin Releasing Hormone

It is also called GnRH or LHRH. It controls the release of the Gonadotrophins -FSH and LH (Please see below) from the pituitary.

Thyroid Releasing Hormone TRH

This hormone controls the release of Thyroid Stimulating Hormone -TSH (Please see below) from the pituitary.

Antidiuretic Hormone ADH, Vasopression

This hormone passes through the pituitary gland and acts on the kidneys to control the fluid output and electrolyte balance of the body.

 DIFFERENT HORMONES PRODUCED FROM THE PITUITARY

Thyroid Hormone (TSH)

The pituitary produces TSH which circulates to the thyroid stimulating this gland in your neck to make and release thyroid hormones called Thyroxine and Tri-iodothyronine

OVERPRODUCTION Abnormal growth of the pituitary (pituitary adenoma) involving the cells, which produce excess of TSH, can occur rarely producing an overactive thyroid.

UNDERPRODUCTION It can happen for an unknown reason (hypothyroidism) or as part of the HYPOPITUITARY State. (Please see HYPOPITUITARY).

Adrenocorticotrophic hormone (ACTH).

This hormone stimulate the adrenal glands (small endocrine glands situated on the top of your kidneys) to produce cortisol. This is a steroid hormone which is essential for the everyday activities and health. Lack of cortisol causes severe fatigue and lack of appetite with weight loss.

OVERPRODUCTION Abnormal growth of the pituitary (pituitary adenoma) involving the cells which produce excess of ACTH will cause over stimulation and abnormally high levels of cortisol production from the adrenal glands. (Please see CUSHING'S DISEASE/SYNDROME)

UNDERPRODUCTION Isolated under production of this hormone is very rare. This can happen with HYPOPITUTARY STATUS. (Please see HYPOPITUITARY)

Growth Hormone (GH)

This has effects on the various tissue of the body. In children, it is essential to reach the normal growth. In adult, it appears to maintain normal energy levels and to keep body tissue such a muscle and bones strong and healthy.

OVERPRODUCTION Abnormal growth of the pituitary (pituitary adenoma) involving the cells, which produce excess of GH, will cause excessive growth. It is called Gigantism in child and ACROMEGALY (please see Acromegaly) in adults.

UNDERPRODUCTION It can happen for an unknown reason or as part of the HYPOPITUITARY State. (Please see HYPOPITUITARY). This will cause short stature in a child and can be responsible for the abnormal lack of energy and change in body composition of the Hypopituitary State (see GH in adults).

Gonadotrophins

These include Follicular Stimulating Hormone (FSH) and Luteinising Hormone (LH). These hormones have effects on the ovaries, uterus, and on the testes in man. These hormones regulate and control the male and female hormones, menstrual cycles, ovulation, sperm production and fertility.

OVERPRODUCTION Abnormal growth of the pituitary (pituitary adenoma) involving the cells, that produce excess of FSH, LH is rare. The excess hormones do not usually make you feel anything different.

UNDERPRODUCTION It can happen for an unknown reason or as part of the HYPOPITUITARY State. (Please see HYPOPITUITARY, INFERTILITY)

Prolactin PRL

This hormone stimulates the breasts and regulates the milk production. It is normally produced in very high levels during the pregnancy and breast- feeding. Its levels can also be very high with use of anti sickness drugs, opiate compounds, stress and any kind of stimulation of the breasts and under active thyroid function. This hormone can be responsible for irregular periods and the lack of sexual desire.

OVERPRODUCTION Abnormal growth of the pituitary (pituitary adenoma) involving the cells, which produce excess of prolactin, is relatively common (prolactinoma). This condition can lead to irregular or absence of periods, infertility, and abnormal spontaneous secretion from the breasts, lack of sexual desire and impotency with breast development in men.

UNDERPRODUCTION This does not usually happen although it can be a part of hypopituitary state. (Please see HYPOPITUITARY) This does not usually have untoward effects apart from one situation, failure of milk production after the delivery of the baby.

Antidiuretic hormone (ADH)

This hormone circulates to the kidneys where it regulates the amount of urine produced.

OVERPRODUCTION This can occur in certain cancers and also rare lung infections (such a mycoplasma pneumonia) where the patient becomes waterlogged due to high ADH causing too much fluid retention by the kidneys.

UNDERPRODUCTION

It can happen in isolation in certain families and for unknown reasons or as part of the HYPOPITUITARY status. (Please see HYPOPITUITARY). Too little ADH causes continual thirst and copious output of urine day and night (diabetes insipidus).

For further information why not contact;

The Pituitary Foundation
PO Box 1944
Bristol, BS99 2UB.
Tel/Fax 0117 927 3355
e-mail- helpline@pitpat.demon.co.uk

or www.pituitary.org.uk

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