Principles of Principles of EndocrinologyEndocrinology
Department of Endocrinology
First Affiliated HospitalSun Yet-sen University
Cao Xiaopei
Principles of EndocrinologyPrinciples of Endocrinology
Glands
Hormones
EndocrineEndocrine
hormones from specialized cells hormones from specialized cells in glands or tissue are in glands or tissue are secrected and transported in secrected and transported in the blood to a distant site of the blood to a distant site of action(classic “endocrine” action(classic “endocrine” effect), or act directly upon effect), or act directly upon nearby cells which is called nearby cells which is called “paracrine” activity. “paracrine” activity.
ExocrineExocrine
products from glands are products from glands are secrected externally or secrected externally or into a lumen, such as the into a lumen, such as the gastrointestinal tract.gastrointestinal tract.
Endocrine SystemEndocrine System
Elements of endocrine system:Elements of endocrine system: Endocrine organsEndocrine organs APUD system APUD system Hormonal secrentory cells Hormonal secrentory cells
Major endocrine organs and common endocrine Major endocrine organs and common endocrine problemsproblems
OOther endocrine ther endocrine sites sites Islet : insulin ( βcell )、 glucagon ( αcel
l ) somatostatin 、 VIP…
Mucosa in GI tract :gastrin 、 cholecystokinin 、 secretin 、 VIP…
Kidney: 1,25-(OH)2D3, Renin , EP , PG…
Lung : APUD…
Heart : natriuretic peptide…
Endothelial cell : endothelin…
HormoneHormone
Chemical messengers produced Chemical messengers produced by a variety of specialized by a variety of specialized secretory cellssecretory cells
Chemical signals secreted into Chemical signals secreted into the blood stream that act on the blood stream that act on distant tissues, usually in a distant tissues, usually in a regulatory fashionregulatory fashion
Sources of HormonesSources of Hormones
Hormone secretory cells Hormone secretory cells (found around human body) (found around human body)
Endocrine glandsEndocrine glands Tissues or cells of endocrine Tissues or cells of endocrine
function:function:neurosecretory celneurosecretory cells in hypothalamus, ls in hypothalamus, hormone secretory cells/organ cells hormone secretory cells/organ cells with endocrine function in GI tract, with endocrine function in GI tract, kidney, heart, lung, etckidney, heart, lung, etc
Hormones involved in Hypothalamus-Pituitary axis and Hormones involved in Hypothalamus-Pituitary axis and their functiontheir function
Classification of HormoneClassification of Hormone
Amino acid derivatives: dopamine, Amino acid derivatives: dopamine, catecholamines, thyroid hormone(TH)catecholamines, thyroid hormone(TH)
Small neuropeptides: gonadotropin-Small neuropeptides: gonadotropin-releasing hormone(GnRH), thyrotropin-releasing hormone(GnRH), thyrotropin-releasing hormone(TRH), somatostatin, releasing hormone(TRH), somatostatin, vasoprssinvasoprssin
Large proteins: insulin, luteinizing Large proteins: insulin, luteinizing hormone(LH), parathyroid hormone(PTH)hormone(LH), parathyroid hormone(PTH)
Steroid hormones: cortisol, estrogenSteroid hormones: cortisol, estrogen Vitamin derivatives: retinoid(VitA), Vitamin derivatives: retinoid(VitA),
vitamin D, a variety of peptide growth vitamin D, a variety of peptide growth factorsfactors
Synthesis, Storage and Release Synthesis, Storage and Release of Hormonesof Hormones
Peptide hormones: Peptide hormones:
Neural or endocrine stimulationNeural or endocrine stimulation → → transcription from DNAtranscription from DNA → mRNA → → mRNA → peptide productpeptide product → → posttranslational posttranslational protein processingprotein processing → → intracellular sorting, intracellular sorting, membrane integrationmembrane integration → → storage or storage or secretionsecretion. .
Synthesis and Processing of Synthesis and Processing of
InsulinInsulin
Synthesis, Storage and Synthesis, Storage and Release of HormonesRelease of Hormones
Steroid hormone:Steroid hormone:
Synthesis of most steroid hormones Synthesis of most steroid hormones is based on modifications of the is based on modifications of the precursor and cholesterol. precursor and cholesterol.
Multiple regulated enzymatic steps Multiple regulated enzymatic steps are required for the synthesis of are required for the synthesis of testosterone, estradiol, cortisol and testosterone, estradiol, cortisol and vitamin D . vitamin D .
Patterns of secretionPatterns of secretion
Hormone secretion is continuous(e.g. Hormone secretion is continuous(e.g. thyroid hormone) or intermittent(e.g. thyroid hormone) or intermittent(e.g. LH,FSH).LH,FSH).
Biological rhythms ------ CircadianBiological rhythms ------ Circadian Circadian means changes over the 24 Circadian means changes over the 24
hours of the day-night cycle and is best hours of the day-night cycle and is best shown for the pituitary-adrenal axis.shown for the pituitary-adrenal axis.
Plasma cortisol levels during a 24-Plasma cortisol levels during a 24-
hour periodhour period
Hormonal and follicular changes during Hormonal and follicular changes during the normal menstrual cyclethe normal menstrual cycle
The menstrual The menstrual cycle is the cycle is the best example best example of a longer and of a longer and more complex more complex (28-day) (28-day) biological biological rhythm. rhythm.
Patterns of secretionPatterns of secretion
Clinical significance of recognising Clinical significance of recognising rhythms of hormonal secretion:rhythms of hormonal secretion:
1. 1. Testing the hormone Testing the hormone
concentrationconcentration
2. 2. Hormonal replacement therapyHormonal replacement therapy
Patterns of secretionPatterns of secretion
Other regulatory factorsOther regulatory factors StressStress SleepSleep Feeding and fastingFeeding and fasting
Plasma Transport of Plasma Transport of HormonesHormones
HormoneHormone Binding protein(s)Binding protein(s)Thyroxine (T4)Thyroxine (T4) Thyroxine-binding globulin Thyroxine-binding globulin
(TBG)(TBG)
Thyroxine-binding prealbumin Thyroxine-binding prealbumin (TBPA) (TBPA)
AlbuminAlbumin
Triiodothyronine Triiodothyronine (T3) (less bound (T3) (less bound than T4)than T4)
Thyroxine-binding globulin Thyroxine-binding globulin (TBG)(TBG)Albumin Albumin
Testosterone, Testosterone, estradiol estradiol
Sex hormone-binding globulin Sex hormone-binding globulin (SHBG) (SHBG)
Insulin-like growth Insulin-like growth factor-I (IGF-l) factor-I (IGF-l)
IGF-binding proteins (mainly IGF-binding proteins (mainly IGF-BP3) IGF-BP3)
Cortisol Cortisol Cortisol-binding globulin Cortisol-binding globulin (CBG) (CBG)
Hormones ,their receptors and pathwaysHormones ,their receptors and pathways
Degradation of Degradation of HormonesHormones
Hormone transport and degradation Hormone transport and degradation dictate the rapidity with which a dictate the rapidity with which a hormonal signal decays. Some hormonal signal decays. Some hormonal signals are evanescent hormonal signals are evanescent (e.g.somatostatin), whereas others (e.g.somatostatin), whereas others are longer lived (e.g. TSH)are longer lived (e.g. TSH)
Most hormones are deactivated in Most hormones are deactivated in live, kidney or peripheral tissues. live, kidney or peripheral tissues. Thus it must be noted that hepatic Thus it must be noted that hepatic insufficiency or renal insufficiency may insufficiency or renal insufficiency may result in prolonged half life of some result in prolonged half life of some hormoneshormones
Metabolism Metabolism
organ functionorgan function
growth growth
development reproduction development reproduction
Maintainance of homostasis of Maintainance of homostasis of
internal enviromentinternal enviroment
Functions of HormonesFunctions of Hormones
FeedbackFeedback
Hypothalamus Pituitary-target gland axis
Hypothalamus Pituitary thyroid axis
Hypothalamus Pituitary adrenal axis
Hypothalamus Pituitary gonad axis
Endocrine and metabolism
Insulin vs glucose
PTH vs calcium
ADH vs plasma osmotic pressure
Hypothalamus Pituitary Hypothalamus Pituitary thyroid axisthyroid axis
Hypothalamus Pituitary Hypothalamus Pituitary adrenals axisadrenals axis
Hypothalamus Pituitary gonad Hypothalamus Pituitary gonad axisaxis
Insulin and blood glucoseInsulin and blood glucose
Classification of endocrine Classification of endocrine diseasedisease
1. primary endocrine disorder
2. secondary to other disease
3. ectopic endocrine disorder
4. due to receptor dysfunction
5. heredity abnormal hormones
6. iatrogenic
Clinical picturehistory 、 symptom 、 signLab findings evidence of metabolic disturbance: target tissue or/and organs function
evidence of inappropriate hormone : hormones or their metabolite of
endocrine function test immunology
Diagnosis
ImageologyX ray , CT , B
ultrasound , isotope
Histology and cytology
Cytogenetics
Diagnosis
Typical features in endocrine disease
dwarfism
gigantism
acromegaly
Typical features in endocrine disease
Cushing
syndrome
hyperthyroidism
Cretinism
Addison
disease
Principal of Principal of diagnosisdiagnosis functional Cushing’s symdrome pathology adrenal hyperplasia etiology pituitary microadenoma complications diabetes diabetic nephropathy concurrent disease hypertension cataract
prophylaxis : endemic goiter Iodine deficiencyiodine replacement
Treatment : hyperfunctioning medicine 、 surgery 、 radiation hypofunction hormones replacement and
transplantation symptomatic and supporting therapy
prophylaxis and prophylaxis and treatmenttreatment
Thank you for your attentionThank you for your attention!!