Other Hormones http://www.scribd.com/doc/14027/MEDICAL-PHARMACOLOGY-AT-A-GLANCEI found this site to be very helpful with information on many types of drugs along with pictures to illustrate their mechanism of action. Its an onlince book called Medical Pharmacology at a glance.

What are hormones?

Hormones are chemical messengers that regulate bodily processes such as growth, reproduction, metabolism, digestion, mineral and fluid balance, and the functioning of various organs. Hormones exert substantial control over the following behavior patterns: parental care, territorial behavior, metamorphosis (in insects), foraging behavior, and circadian rhythms (behavior patterns that always occur at the same time each day).
Most hormones fall into two main categories:

· peptides (chains of amino acids)
· lipids (which include steroids).
Endocrine System
Endocrine System

The Endocrine System

The major endocrine glands are
1- The pituitary located at the base of the brain
2- The thyroid
3- The parathyroid in the neck,
4- The pancreas,
5- adrenals
6- gonads (reproductive glands) in the torso.

Pituitary Gland
The Process of Active Transport
The Process of Active Transport

· The pituitary gland is composed of two lobes, the anterior pituitary and the posterior pituitary.
· The anterior pituitary produces six major hormones (see chart below), the most abundent hormone is GH or growth hormone.
-The direct effect of GH include: lipolysis in fat cells and stimulation of hepatic glucose output. (Opposite effects of insulin). The indirect effects include: insulin like, growth promoting factor. Somtimes this is abused by athletes due to the lean muscle building mass that occurs and the potent anabolic agent. The GH releasing hormone is more prominently used in growth retardation children and may have role in clinical managment of burn injuries.
Adverse effects of growth hormone include: Diabeties in AIDS patients, decreased insulin sensitivity with a posible increase in diabetes type 2 in children. Arthralgia in the hands and wrist, headaches and intercranial hypertension.
·
The posterior pituitary stores two hormones originating in the hypothalamus (Vasopressin and Oxytocin).
-Vasopressin: acts on kidney to increase water reabsorpion. Plays important role in long term control of blood pressure. May be given IV, IM, or intranaslly. It is rapidly metabolized in kidney and liver. Vasopressin is also used to control bleeding in certain conditions such as von Willebrand factor and clotting factor VII and is used to treat certain types of hemophillia.
There are two subtypes of vasopressin: V1 and V2.
V1: Pathway responsible for vasoconstrictor action of vasopressin.
V2: Stimulation leads to antidiureteic effect. Lack of antidiuretic hormone leads to diabetes insipidus, resulting in polyuria and polydipsia. Long acting synthetic analogue acts predominently for the treatment of diabetes insipidus.
-Oxytocin: When stimulated to an increase in intracellular calcium and muscle contraction. Also causes contraction of uterine smooth muscle and may initiate labor. Oxytocin may also stimulate milk ejection in lactting mothers by stimulation myopepithelial cells areound the alveoli of te mamary glands by being administered intraveinously. Oxytocin is metabolized in liver and kidneys but not bound to plasma protein so it has a very short circulating half life of 5 minutes.

· The pituitary's target endocrine glands are the thyroid, adrenal gland, and the gonads
· Controls the growth of the skeleton and regulates the functions of the thyroid and the gonads.

Thyroid Hormones

· Stimulates oxygen consumption and metabolism
· Regulate the growth of body tissues and the rate at which food is burned to provide body energy.
· Over activity = hyperthyroidism, which causes nervousness and irritability. Another thyroid condition, cretinism, is caused by a congenital lack of thyroid secretion. It is marked by greatly stunted physical and mental growth.

Insulin and Glucagon

· The pancreas produces two important hormones, insulin and glucagon.
· Insulin is involved in the metabolism of carbohydrates, proteins, and fat.

Adrenal Glands and Gonads

· Hormones in the adrenal glands control the concentration of salts and water in body fluids and are necessary for maintaining life.
· Produce sugar from proteins and store it in the liver to help maintain resistance to physical and emotional stress.

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Actions of insulin:

To lower blood glucose concentration
Pharmacokinetics:
· Biotransformed in variety of organs including liver kidney and skeletal muscles.
· Metabolism of insulin results in inactive peptides
· Half life is approximately 8 minutes in a non diabetic patient

The Insulin Receptor and Mechanism of Action

· The insulin receptor is composed of two alpha subunits and two beta subunits linked by disulfide bonds.
· The alpha chains are entirely extracellular and house insulin binding domains, while the linked beta chains penetrate through the plasma membrane.
· The insulin receptor is a tyrosine kinase.
· It functions as an enzyme that transfers phosphate groups from ATP to tyrosine residues on intracellular target proteins.
· Binding of insulin to the alpha subunits causes the beta subunits to phosphorylate thus activating the catalytic activity of the receptor.
· The activated receptor then phosphorylates a number of intracellular proteins, which in turn alters their activity, therefore generating a biological response.

Insulin Deficiency and Excess Diseases

Thyroid hormone medications for hypothyroidism



Examples

Generic Name
Brand Name
desiccated thyroid (not recommended for replacement therapy)
Armour Thyroid
levothyroxine sodium (T4)
Levothroid, Levoxyl, Synthroid
liothyronine sodium (T3)
Cytomel
liotrix (T3 and T4)
Euthroid, Thyrolar
Thyroid hormones are taken by mouth (orally) except in unusual cases, such as [[javascript:popoffwindow('../../../../glossary/d4412/d44127247/def.htm')|myxedema coma]]. That condition requires [[javascript:popoffwindow('../../../../glossary/sti17/sti17216/def.htm')|intravenous (IV)]] medicine. Dosages vary with the person's age and the severity of the disease.

How It Works

People with [[javascript:popoffwindow('../../../../glossary/sth15/sth150012/def.htm')|hypothyroidism]] have lower-than-normal or no thyroid function and do not make enough thyroid hormone for the body to function properly. Taking thyroid hormone medicine replaces missing hormones.

Why It Is Used

Thyroid hormone medicines are given when blood tests indicate you have hypothyroidism.
Thyroid hormone medicines also may be prescribed:
  • For [[../../frame/hw145/hw145385/frame.htm|mild (subclinical) hypothyroidism]] when you test positive for [[../../frame/te256/te2562/frame.htm|antithyroid antibodies]].
  • For an enlarged thyroid gland ([[javascript:popoffwindow('../../../../glossary/stg12/stg124260/def.htm')|goiter]]).

How Well It Works

People with hypothyroidism who take thyroid hormone medicine usually notice:
  • Improved energy level.
  • Gradual weight loss (in people with severe hypothyroidism at the time of diagnosis).
  • Improved mood and mental function (thinking, memory).
  • Improved pumping action of the heart and improved digestive tract function.
  • Reduction in the size of an enlarged thyroid gland (goiter), if you have one.
  • Improved growth, school performance, and behavior in children. Children whose growth has been delayed because of hypothyroidism start growing normally again once they get adequate doses of thyroid hormone.
  • Lower [[javascript:popoffwindow('../../../../glossary/stc12/stc123682/def.htm')|cholesterol]] and [[javascript:popoffwindow('../../../../glossary/stt11/stt11648/def.htm')|triglyceride]] levels.
In most cases, thyroid hormone medicine works quickly to correct symptoms.
Myxedema coma can respond well to thyroid hormone medicine and treatment in an intensive care unit. But a good outcome depends on how soon treatment starts.

Side Effects

In general, you will not have side effects if you are taking the correct amount of thyroid hormone medicine.
Side effects of too much thyroid medicine include:
  • [[javascript:popoffwindow('../../../../glossary/stp12/stp1297/def.htm')|Heart palpitations]].
  • Nervousness.
  • Trouble sleeping (insomnia).
  • Shaking (tremors).
  • Frequent bowel movements.
  • Too much weight loss.
  • Discomfort in warm weather.
  • Bone thinning ([[javascript:popoffwindow('../../../../glossary/sto16/sto167501/def.htm')|osteoporosis]]) if the dose is too high for a long time.
Report any side effects to your doctor.
If you have [[javascript:popoffwindow('../../../../glossary/stc12/stc123750/def.htm')|coronary artery disease]] and you take too much thyroid medicine, symptoms such as chest pain ([[javascript:popoffwindow('../../../../glossary/sta12/sta123258/def.htm')|angina]]) or heart rhythm irregularities (arrhythmia) may get worse. Also, you may have an increased risk of heart attack.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

Pituitary Hormones:

Hormone
Target(s)
Function
ACTH
Adrenals
Stimulates the adrenal gland to produce a hormone called cortisol.
ACTH is also known as corticotrophin.
TSH
Thyroid
Stimulates the thyroid gland to secrete its own hormone, which is called thyroxine.
TSH is also known as thyrotrophin.
LH & FSH
Ovaries (Women)
Testes (Men)
Controls reproductive functioning and sexual characteristics. Stimulates the ovaries to produce estrogen and progesterone and the testes to produce testosterone and sperm.
LH and FSH are known collectively as Gonadotrophins. LH is also referred to as Interstitial cell stimulating hormone (ICSH) in males.
PRL
Breasts
Stimulates the breasts to produce milk. This hormone is secreted in large amounts during pregnancy and breastfeeding, but is present at all times in both men and women.
GH
All cells in the body
Stimulates growth and repair. Research is currently being carried out to identify the functions of GH in adult life.
MSH

Exact role in humans unknown, but increases skin pigmentation in amphibians.
ADH
Kidneys
Controls the blood fluid and mineral levels in the body by affecting water retention by the {kidney} kidneys.
This hormone is also known as vasopressin or arginine vasopressin (AVP).
Oxytocin
Uterus
breasts
Affects uterine contractions in pregnancy and birth and subsequent release of breast milk.
Control of hormone production is monitored continuously and regulated using