300 likes | 1.33k Vues
Oral Contraceptives. Estrogen and Progestin. What we will be talking about today. Hormones Ovulation History of Oral Contraceptives Uses of Oral Contraceptives Estrogen and Progestin Types of Oral Contraceptives Future of Oral Contraceptives. Hormones .
E N D
Oral Contraceptives Estrogen and Progestin
What we will be talking about today • Hormones • Ovulation • History of Oral Contraceptives • Uses of Oral Contraceptives • Estrogen and Progestin • Types of Oral Contraceptives • Future of Oral Contraceptives
Hormones = “chemical messenger from one cell to another” 4 classes of Hormones • Amine Derived Hormones • Peptide Hormones • Steroid Hormones • Lipid and Phospholipid Hormones Steroid Hormones -derived from cholesterol -primarily produced in adrenal cortex or gonads Types of Steroid Hormones • Anabolic steroids • Corticosteroids • Sex hormones Major steps in Steroid Hormone Binding • http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter47/animations.html# cholesterol
Ovulation • Follicular phase • LH and FSH concentrations increase due to GnRH • Follicular growth • Antrum fluid volume increases • Blister forms in ovary • Ovulation Phase • Follicle released from ovary secretes estrogen • Corpus lueteum triggers release of progesterones and estrogens
History of Oral Contraceptives • 1937- discovery of effects of progesterone on ovulation • 1940’s- Russell Marker isolates progesterone from Mexican yams • 1951- Luis Miramontes synthesizes 1st progestin • 1960- FDA approves “the pill” • 1963- 1st oral contraceptive put on drug market • 1965- number one form of birth control • Late 1970’s- FDA mandated warning that indicated oral contraceptives carried risks of cancer and blood clots
Uses of Oral Contraceptives • Primary Use • Prevent pregnancy • Secondary Uses • Heavy or irregular menstruation • Endometriosis • polycystic ovary syndrome • dysfunctional uterine bleeding
What’s in “The Pill” • 20-40 micrograms ethinyl estradiol (synthetic form of estrogen) • Varying amounts of either levonorgestrel or norethindrone as the progestagen component • Types of Regimens • 21-day or 28-day pack
Combined mode of action of estrogen and progestin • Prevents ovulation • Thickens mucous in cervix • Thins endometrium
Gonadotropin Releasing Hormone (GnRH) • Synthesized by hypothalamus • Stimulates anterior pituitary gland to release FSH and LH • A decapetide (contains 10 amino acids) pGlu-His-Tyr-Gly-Leu-Arg-Pro-Gly-NH2 • secretion begins at puberty • Primary Effects • secretion of estrogen and progesterone in females • secretion of testosterone in males
Estrogen • Primary female sex hormone • Roles of estrogen: • To develop secondary female sex characteristics • Thicken the endometrium • Regulate menstrual cycle • Regulation • Production of estrogen regulated by Follicle Stimulating hormone (FSH) and Luetinizing hormone (LH), both produced in the anterior lobe of the pituitary gland • Hypothalamus→GnRH→ Pituitary→FSH→Follicle→Estrogens
Naturally occurring estrogens Estradiol Estriol Estrone
Conversion of testosterone to estradiol Testosterone Estradiol
Estrogen Receptors Two types of Receptors • ER alpha • ER beta Mode of Action- 1) Estrogen passes through phospholipid bilayer 2) Ligand binds in hydrophobic region of receptor forming cap over ligand binding pocket 3) Estrogen and ER complex bind to estrogen response element in the nucleus to initiate transcription 4) Translation creates proteins which target various organs and processes in the female body
Progesterone • Produced by • Adrenal glands • Gonads • Brain • Placenta (only during pregnancy) • Regulation- stimulated by the production of LH • Hypothalamus→GnRH→ Pituitary→LH→Corpus luteum→Progesterone • Primary Effect-prepares uterus for implantation by the proliferation of endometrium; prepares body for pregnancy • Natural progesterone- destroys digestive system when consumed orally ALL oral contraceptives contain progestin, synthetic form of progesterone
Conversion of pregnenolone to progesterone pregnenolone progesterone
Progestins • Types 1) C19- derived from testosterone 2) C21- derived from progesterone • Role • in adequate doses it inhibits ovulation • Makes your body think that it is pregnant • Reduces levels of FSH and LH • Binding • Interacts with progesterone receptors either by entering cells through phospholipid bilayer or by interacting with surface proteins
Brands of Oral Contraceptives • Loestrin • Lo/Ovral • Mircette • ModiCo • Necon • N.E.E. • Nelova • Nordette • Norethin • Norinyl • Ortho-Cept • Ortho-Cyclen • Ortho-Novum • Ortho Tri-Cyclen • Ovcon • Ovral • Tri-Levlen • Tri-Noriny • Triphasil • Trivora • Zovia • Alesse • Brevicon • Cyclessa • Demulen • Desogen • Estrostep • Genora • Intercon • Jenest • Levlen • Levlite • Levora
Side Effects of Oral Contraceptives • Changes in: • Weight • Sexual desire • Vaginal discharge • Menstrual flow • Breast size • Blood pressure • complexion • Other Common side effects: • Breakthrough bleeding • Nausea headaches • Urinary tract infection • Depression • Gum inflammation
Future of Oral Contraceptives • Researchers continually trying to minimize adverse side effects of oral contraceptives • Pharmaceutical companies have to compete with latest forms of contraception • Contraceptive vaccines • Vaginal rings • Intrauterine Contraception • Cervical caps • Transdermal patch • Implants and injectables
References • http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601050.html • http://en.wikipedia.org/wiki/Estrogen • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SexHormones.html • http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookREPROD.html • http://en.wikipedia.org/wiki/Gonadotropin_releasing_hormone • http://www.contraceptiononline.org/slides/slide01.cfm?q=progestin+chemical+structures&dpg=1 • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hormones.html • http://www.contraceptiononline.org/contrareport/article01.cfm?art=93 • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/G/G_Proteins.html