Transcript Historical perspective of endocrinology

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
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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