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Historical perspective of endocrinology Beginning of science • When do scientific explorations begin? • Early science – Linked to medicine rather than intellectual curiosity – Some behaviors/traditions • No scientific understanding • Scientific merit History of endocrinology • Blood drinking and organ eating – Gaining strength – Gaining advantage over enemy – Treatment for diseases (organotherapy) • Impotence • Endocrine disorders • What is in the blood? – Source of life (Leviticus 17:11) Egyptians • Understanding the role of gonads (ovaries and testis) in sexual reproduction – Fertility and contraception – Removal of ovaries • No pregnancy – Removal of testis • Eunuchs serving in Pharaoh’s harem – Use of tampons as a contraceptive • Materials from male are responsible for pregnancy Egyptians • Methods of pregnancy diagnosis – Morning sickness • Detection of diabetes – Excessive thirst • Laid the foundation Greeks • Hippocrates (father of medicine) – First known physician • Many clinical Observations • Considered medicine as science and separated practice from religion Greeks • Hippocrates – Theory of inheritance • Pangenesis theory (Seeds come from all parts of body and stored in testis) – Theory of four humors • Black bile, yellow bile, phlegm (green), and blood • Correction of health problems through balancing four humors – Sexing of offspring through testis removal • Right-male • Left-female – Identification of vascularized glands Greeks • Aristotle – History of animals • Sows – Loss of ovaries via ovariectomy • Contraception • Increased growth – Argument against preformation theory • Embryo dissection – Methods of contraception • • • • Diet (obesity/starvation) Rhythm method Ovariectomy Vaginal and cervical environment manipulation Romans • Organoectomy and organotherapy – Eating brain for epilepsy – Eating testis for impotence Romans • Galen – Discovery of thyroid gland • Ductless gland similar to salivary gland – Vital spirit • Substances from brain being carried into the blood – Pituitary gland • Storage of waste products from brain Romans • Galen – Peri Spermatos (on seed) • Castration – Decreased libido – Changed fat deposition – Changed hair distribution • Substance from testis affected physical characteristics Middle ages • No significant progress in science – Domination of church • Diseases = act of God • Surgery = dirty medical practice • Chinese – Cure for Goiter • Consumption of seeweed and shellfish • Dysfunction of thyroid gland – Cause of diabetes • Chinese – Testicular organotherapy – Extraction of steroid and metabolites from urine • Varying drying temperature to isolate different steroids Renaissance (rebirth) • Explosion of arts and science – Anatomy • Da Vinci and Michelangelo – Galileo Galilei – Development of miscroscope and telescope • Robert Hooke – Discovery of cells • Antoine van Leeuwenhoek – Discovery of sperms Renaissance (rebirth) • William Harvey – Circulation of blood – Refuted preformation theory • Dissection of uterus immediately after mating – No congealed mass – No female/male parts • De Bordeaux (vitalist) – Emanation from each organ is crucial for health • No experiments Renaissance (rebirth) • Discovery of iodine as a treatment for Goiter – Bernard Courtois First endocrinology experiment First endocrinology experiment • Hunter and Berthold – Growth of organs during transplantation • Rooster as a model • Removal of testis – Removal of male characteristics (comb) • Transplantation of testis – Normal male characteristics • Characteristics controlled by substance in blood, not by nerves – Completely disconnected testis Contemporaries • Claude Bernard – Exocrine vs. Endocrine gland (liver) • Bile from gall bladder • Internal secretion (glucose from hepatic glycogen) • Thomas Addison – Link between adrenal dysfunction and blood • Addison’s disease (hypoadrenalism) • Brown-Sequard – Organotherapy • Extract from testis to rejuvenate older men • George Murray – Hypothyroid (myxoedematous) patients can be treated successfully with thyroid extract • Von Merring and Minkowski – Relationship between diabetes and pancreas dysfunction • Removal of pancreas resulted in constant urination • Urine from dogs attracted houseflies when their pancreas were removed • Hale White – Feeding pancreas/injection of pancreas extract to treat diabetes • Did not work (allergic reaction/too little insulin being stored in pancreas) • Pierre Marie – Pituitary gland tumor as a cause of acromegaly • Excessive growth hormone from tumor resulted in excessive growth • Feeding of dried pituitary gland – No effects on growth • Oliver and Schafer – Relationship between adrenal gland and blood pressure • Extract from adrenal medulla and pituitary gland caused increase in blood bressure • Extract from thyroid gland caused fall in blood pressure – “On Internal Secretion” (1895) Discovery of the first hormone • Starling and Bayliss – Interaction between duodenum loop and pancreas • Passing of foodstuff (chyme, highly acidic) through duodenal loop stimulated release of enzyme by pancreas • Initial thought – nervous system (vagus nerve) • Denervated duodenum stimulated release of pancreatic enzymes when stimulated with acid – Chemical reflex rather than nerve reflex – Reaction through blood • Discovery of secretin What is in the name? • Hormone – Greek “I excite” or “I arouse” – Transported by blood from one organ, which secretes the substance, to the organ where the effect is exerted