Steroid Hormones(13.10-13.12)

1. Steroid Hormones(13.10-13.12) Jack Snyder James Sanders

2. Chapter 13 Section 10 • What are some of the Physiological Roles of Steroid Hormones? • Cholesterol is the starting material for the synthesis of steroid hormones • Progesterone serves as the starting compound for both sex hormones and the adrenocorticoid hormones • A. Adrenocorticoid Hormones • The adrenocorticoid hormones are products of the adrenal glands • Classified into two groups according to function: Mineralocorticoids and Gluccocorticoids. • Mineralocorticoids regulate the concentrations of ions (mainly Na+ and K+) • Gluccocorticoids control carbohydrate metabolism

3. Chapter 13 Section 10 cont. • An oxidation product of cholesterol is progesterone, which is a sex hormone. It also gives rise to the synthesis of other sex hormones, such as testosterone and estradiol . • Progesterone is also a precursor of the adrenocorticoid hormones. Within this group cortisol and cortisone are best known for their anti-inflammatory action.

4. Chapter 13 Section 10 cont. • Anabolic Steroids • Made from testosterone to increase muscular development • Disadvantages • Affects secondary sexual characteristics and too much can result in undesirable side effects • Not very effective when taken orally, must be injected to achieve the best results.

5. Chapter 13 Section 10 cont. • Hormonal Cycle • Levels of the sex hormones during the blood stream of the phases of one menstrual cycle in which pregnancy does not occur. • Development of an ovarian follicle during the cycle. • Phases of development of the endometrium, the lining of the uterus. • The endometrium thickens during the proliferative phase. The secondary phase which follows the ovulation, the endometrium continues to thicken and the glands secrete a glycogen-rich nutritive material in preparation to receive an embryo.

7. Chapter 13 Section 10 cont. • Oral Contraception • Prevents ovulation during pregnancy • In the pill a synthetic progesterone-like compound is supplied together with an estradiol-like compound • Triple bond derivatives of testosterone are used most often in birth control pills • Norethindone • Norethynodrel • EthynodiolDiacetate

9. Chapter 13 Section 11 • Bile salts are oxidation products of cholesterol • They emulsify all kinds of lipids, including cholesterol and are essential in the digestion of fats

10. Chapter 13 Section 11 cont. • Bile salts can disperse dietary lipids in the small intestine into fine emulsions, there by facilitating digestion. • Remove excess cholesterol: • They are themselves breakdown products of cholesterol, so cholesterol is eliminated via bile salts. • They solubilize deposited cholesterol in the form of bile salt

11. Chapter 13 Section 12 • Prostaglandins • Group of fatty acid like substances were discovered by Kurzrok and Leib in the 1930s when they demonstrated that seminal fluid cause a hysterectomized uterus to contract • Isolated these compounds from human semen and, thinking it came from the prostate gland, named them prostaglandins • It is synthesized from Arachidonic acid (ring closure)

12. Chapter 13 Section 12 cont. • Thromboxanes • Derivative of arachidonic acid (ring closure) • Is known to induce platelet aggression • Causes other platelets to clump, there by increasing the size of the blood clot • Do not use aspirin and anti-inflammatory agents a week before planned surgery because aspirin and other NSAIDS may cause excessive bleeding.

13. Thromboxane + Leukotrienes

14. Chapter 13 Section 12 cont. • Leukotrienes • Group of substances that act to mediate hormonal responses • Derived from Arachidonic acid by an oxidative mechanism • No ring closure • Occur mainly to white blood cells but are also found in other tissues in the body. • Produce long lasting muscle contractions, especially the lungs

15. Chapter 13 Section 12 cont. • Both Prostaglandins and the Leukotrienes cause inflammation and fever, so the inhibition of their production of the body is a major pharmacological concern