Thyroid Stimulating Hormone
Tyrotrope cell
Stimalation of Thyroid hormones and growth
Follicle Stimulating Hormone
Gonadotrope cell
ovarian follicle growth in female
Spermatogenesis in male
Luitenizing Hormone
Ovulation in female
Testosterone in male
Gonadotrope cell
Human Grown Hormone (HGH, Somatotropin
Somatotrope cell
Body growth
Inhibit insulin
Prolactin
Lactotrope
Milk secretion
Maternal behavior
Inhibition of ovulation
Adrenocorticotrophic hormone ( ACTH)
Cortiocotrope
Adrenal cortex secretion
Growth
Steroid production
Beta Lipotropin
Corticotrope
Precursor of endorphin
Oxytocin - Posterior
Paraventricular nuclei
Ejection of milk
Uterine contraction
Arginine Vassopressin-posterior
Supraoptic Nuclei
Water retention
Plasma Osmolarity
Most abundant anterior pituitary hormone
Growth Hormone.
HGH specific effect is
Stimulation of Linear bone growth through the epiphyseal cartilage plate of long bone
Acromegaly vs Gigantism
Acromegaly: Excess GH after epiphyseal closes— bone thicker not longer
Gigantism : Excess GH before epiphyseal plate closes . Long bones
Growth Hormone Metabolic effects
Anabolic: Increase synthesis of protein
Ketogenic: increased mobilization of fatty acid
Diabetogenic: inhibits insulin secretion
Na+ and H2O retention
What stimulates GH?
Hypoglycemia Fasting Estrogen GH- releasing Hormone Sleep Decreased Free Fatty Acid Increased Amino Acid Stress Alpha - adrenergic Dopamine
What inhibits growth hormone
Insulin like growth factor 1
Cortisol- large doses of corticosteroids
Obesity
Pregnancy
Hyperglycemia
Free Fatty acid increase
Growth- Hormone inhibiting hormone ( Somatostatin)
What inhibits release of prolactin
Dopamine
What increases prolactin
Preop anxiety
2 things decrease the secretion of TSH
Corticosteroid
SNS stimulation
How is TSH released?
Proteolysis of thyroglobulin in follicles of thyroid cells
How is T3 produced? Triiodothyronine.
Direct metabolism of tyrosine yields T3 ( it is 5 times more active than T4)
Conversion of T4 in the peripheral tissues
How is T4 produced ? Thyroxine
Prohormone synthesized by Thyroxine , is 80% of the thyroid hormone in circulation . It serves as prohormone to T3
1/2 life T3- T4
T3: 1.5 days
T4: 7 days
Thyroid and O2 consumption
Thyroid hormone increased O2 requirement in all tissue except brain = Minimal changes in MAC requirement for patient with hyper or hypothyroidism
Excess= tissue O2 consumption increased by 100%
Absent= tissue O2 consumption decrease by 40%
Thyroid secretes
T3
T4
Calcitonin
Earliest sign of thyroid hormone abnormality
Cardiac changes
Thyroid hormone most effect through
Control of protein synthesis.activated DNA transcription in the cell nuclei = new proteins and enzymes
Cardiac cholinergic receptor numbers and thyroid
They are decreased = not enough inhibitory cholinergics in heart = high HR compared to increase in CO
Thyroid hormone modulates what adrenergic receptors
Al;pha and Beta
How does thyroid increase CO?
Accelaration of metabolism = tissues (not veins) vasodilate= more blood available in the vessels = increased CO but : SBP does not go up bc peripheral vasodilation offset that ( less SVR)
PTH inversely related to
ionized calcium concentration
PTH and calcium
Stimulates release of calcium from bone ( Osteoclasts) ( Bone )
Converts Vit D to active 1,25,Dihydroxicholecalciferol to increase absorb of ca in GI (GI)
Prevents reabsorption of phosphate in renal to increase ca and decrease Phosphate( renal tubule)
Cholesterol is precursor of …
Corticosteroids
What can cause Diabetes . Table 38-2
Type 1+ absolute deficiency destroyed pancreatic B cells
Type2- Insulin resistance and deficiency
Exogenous pancreas disease: hemochromatosis, cystic fibrosis, pancreatitis, pancreatectomy
Gestational
Drug induced: Thiazides, glucocorticoid, thyroid hormone, Beta adrenergic
Endocrinopathy: acromegaly, Cushing syndrome
Defect of pancreatic B cells
Defect of insulin action- resistance
Infection : congenital rubella, CMV
Uncommon immune mediated diabetes : Stiff man syndrome , anti-insulin receptor antibody
Hyperglycemia cause
Impaired vasodilation
Chronic pro inflammatory, prothrombogenic, proartherogenic , = vascular
IV insulin 1/2 time
5- 10 minutes
Insulin metabolized by
Kidney and Liver by proteolytic enzyme
Insulin goes to liver how?
50% goes to liver via the portal vein
Which affects insulin clearance rate more ?
Renal more than liver
Type 2 Diabetes
Oral before Insulin
Pancreatic beta cell dysfunction or auto antibody have developed
Primary Failure of Sulfonylurea
20% of patients started on it do not have adequate hypoglycemic to max dose .,
Secondary Failure of Sufonulurea
Initially responded but then failed to respond
Effects of ETOH and salicylates on BG
Decreases = with sulfonylureas hypoglycemia worse !!!
What meds patient sulfonylureas
Warfarin and Sulfonamide
Risk factors for sulfonylurea hypoglycemia
Poor nutrition
>60 y.o.
Warfarin and sulfa abx- potentiate sulfonylurea
Salicylate and ETOH - decrease BG
Impaired renal function - can’t eliminate
Excretion of Glyburide
50% in feces
The 2 sulfonylurea most likely to cause low BG
Glyburide - long 1/2 time 4.6- 12 hrs- 18/24hrs duration
Chlorpropamide - longest 1/2 time- 30/36 hrs - 36 hrs duration
Which sulfonylurea favorable for renal pts?
Glypizide - feces and only small unchanged in kidney
Torbutamide- only small unchanged in kidney
How does sulfonylurea affect ischemic preconditioning ?
By closing K-ATP channels. Increase CV mortality with sulfonylurea
Sulfonylurea and placenta
Crosses= fetal hypoglycemia
Sulfonylurea with lowest elimination 1/2 life
Acetoheximibe : 1.3 to 6 hrs
Which sulfonylurea can you give with liver dysfunction
Acetoheximibe, bs lower 1/2 life, less prolonged elimination in liver patients = less chances of hypoglycemia