Steroid Hormones Katlyn Raker and Amanda Carl

Physiological roles  Cholesterol is the starting material for the synthesis of steroid hormones  Progesterone  Compound for  Sex hormones  Adrenocorticoid hormones

Adrenocoticoid hormones  Products of adrenal glands  Adjacent to the renal (kidney) o Classified into 2 groups o Mineralocorticoid o Regulate concentrations of ions (Na and K) o Glucocorticoids o Control carbohydrate metabolism

Corticoid  Indicates the site of the secretion is the cortex (outer part of gland)  Aldosterone  Most important mineralocorticoids  Increased secretion of aldosterone enhances the reabsorption of Na and Cl ions in the kidney tubules and increases the loss of K  Controls tissue swelling

 Cortisol  Major glucocorticoid  Increase glucose and glycogen concentration in the body  Fatty acids from fat storage cells and amino acids from body proteins  Transported to liver and under the influence of cortisol it manufactures glucose and glycogen  Cortisol and cortisone (Ketone derivative)  Anti-flammatory effects

Sex hormones  Male- Testosterone  Promotes growth of genital organs  Synthesized in testes from cholesterol  Female- Estradiol  Synthesized from corresponding male hormone by aromatization of the A ring

 Along with progesterone it regulates the cyclic changes in the uterus and ovaries (Period)  Level of estradiol rises uterus thickens

Luteinizing hormone (LH)  Triggers ovulation  Estradiol and progesterone  Promote further preparation of the uterine lining to receive the fertilized ovum  No fertilization means the progesterone production stops and estradiol production decreases

 Progesterone is essential for the implantation of the fertilized ovum  Blocking its action leads to a miscarriage  The levels of sex hormones in the blood stream during a period (menstration) prevent pregnancy  Development of an ovarian follicle  Proliferative phase- The endometrium (lining of the uterus) thickens

 Secretory phase- the lining continues to thicken and the glands secrete a glycogen rich nutritive material in preparation to receive an embryo  If there is no embryo the new outer layers disintegrate which causes blood flow

Mifepristone (RU486)  Blocks action of progesterone by binding to the same receptor sites  Ovum is aborted since the progesterone cannot reach the receptor molecule  If pregnancy is established Mifepristone can be taken no less than 72 hours after intercourse for 49 days of gestation

Facts  Mifepristone is a supplement to surgical abortions  The morning after pill is not an abortion pill  Since estradiol and progesterone regulate the growth of breasts, Mifepristone has been noted to be effective against breast cancer

Bile salts  Oxidation products of cholesterol  Powerful detergents  One end is negatively charged so its strongly hydrophilic  The rest is largely hydrophobic  Disperse dietary lipids in the small intestine into fine emulsions which facilitates digestion  Similar to soap and dirt

Prostaglandis  Group of fatty acid like substances  Discovered by Kurzruk and Leib in the 1930’s  Name came from Ulf von Euler of Sweden who isolated the two compounds from semen, thinking they came from the prostate gland  Mature male= secretes.1mg per day

 Both sexes= a little is present throughout the body  Synthesized in the body from arachidonic acid by a ring closure at carbons 8 and 12  Catalyst= COX (cyclooxygenase)  Aspirin inhibits this enzyme

Thromboxanes  Includes a ring closure  Another class of a arachidonic acid derivative  Induces platelet aggregation  Increases size of blood clot  Aspirin impairs the clotting from thromboxane

Leukotrienes (LTR’s)  Causes inflammation and fever  Acts to mediate hormonal responses  No ring closure  Mostly occur in white blood cells  Produce long lasting muscle contractions especially in the lungs  Can cause asthma like attacks  You would take zafirlukast (Accolate) to help chronic asthma because it acts against the inflammation