Endocrine Flashcards
InsuIin-independent transporters - GLUT1
RBCs, brain, cornea, placenta
InsuIin-independent transporters - GLUT2
(bidirectional): beta islet cells, liver, kidney, GI
InsuIin-independent transporters - GLUT3
brain, placenta
InsuIin-independent transporters - GLUT5
(Fructose): spermatocytes, GI tract
InsuIin-independent transporters - SGLTl/SGLT2
(Na+-glucose cotransporters):
kidney, small intestine
Anabolic effects of insulin: (7)
Anabolic effects of insulin:
• Inc. glucose transport in skeletal muscle and adipose tissue
• Inc. glycogen synthesis and storage
• Inc. triglyceride synthesis
• Inc. Na+ retention (kidneys)
• Inc. protein synthesis (muscles)
• Inc. cellular uptake of K+ and amino acids
• Dec. glucagon release
• Dec. lipolysis in adipose tissue
Unlike glucose, insulin does not cross the placenta.
insulin receptors - tyrosine kinase - activate two pathways:
Phosphoinositide-3 kinase pathway ->glicogen/lipid\protien synthesis + vesicles (GLUT 4)
RAS/MAP kinase pathway -> Cell growth and DNA synthesis
Insulin regulation:
alfa 2 dec.
beta 2 inc.
GHRH Analog
Tesamorelin - used to treat HIV-associated lipodystrophy.
Oxytocin Modulates
fear, anxiety, social bonding, mood, and depression
MD SAFe
TRH increases…
TSH
Prolactin
Dopamine decreases…
TSH
Prolactin
Somatostatin decreases…
TSH
GH
Prolactin increases____ and decreases____.
increases dopamine and decreases GnRH.
____,____,____ increases Prolactin
TRH
Estrogen (pregnancy)
Renal failure
(“RET”)
GHRH induced by
P- Puberty E - Exercise G - hypoGlycemia S - deep Sleep S - Stress
GHRH inhibited by
AGO: Aging Obesity Glucose Somatostatin Somatomedin
other names for GH and IGF-1
GH - somatotropin
IGF-1 - somatomedin C
GH metabolic effects:
dec. glucose uptake and Inc. lipolysis in FAT CELLS
IGF-1 metabolic effects in the BONE:
BONE: Inc. amino acid uptake Inc. Protein synthesis Inc. DNA and RNA synthesis Inc. Chondroitin sulfate Inc. Collagen Inc. Cell size and number
IGF-1 metabolic effects in the Muscle
Inc. amino acid uptake
Inc. Protein synthesis
Cortisol function in general:
Cortisol is A BIG FIB.
Appetite increased
Blood pressure
Insulin resistance (diabetogenic)
Gluconeogenesis, lipolysis, and proteolysis all increase (dec. glucose utilization)
Fibroblast activity decreased (poor wound healing, dec. collagen synthesis - striae)
Inflammatory and Immune responses decreased
Bone formation decreased (dec. osteoblast activity)
Cortisol function - blood pressure mechanisms
- Upregulates alfa 1 - receptors on arterioles - inc. sensitivity to norepinephrine and epinephrine (permissive action)
- At high concentrations can bind to mineralocorticoid (aldosterone) receptors
Cortisol function - Inflammatory and Immune responses mechanisms
just CHILL:
C - Cells: Eosinopenia, lymphopenia
H - Histamin: Blocks histamine release from mast cells
I - IL-2: Blocks IL-2 production
L - leukotrienes and prostaglandins: Inhibits production of leukotrienes and prostaglandins
L - Loose WBC: Inhibits WBC adhesion -> neutrophilia
Calcium homeostasis: Plasma Ca2+ exists in three forms:
Plasma Ca2+ exists in three forms:
• Ionized/free (45%, active form)
• Bound to albumin (40%)
• Bound to anions (15%)
Calcium homeostasis: Regulation of PTH (pH/albumin/Ca2+)
Ionized/free Ca2+ is 1° regulator of PTH
changes in pH alter PTH secretion
changes in albumin concentration do not.
Calcium homeostasis: Inc. pH?
Inc. pH (less H+) -> albumin binds more Ca2l+ -> dec. ionized Ca2+ (eg, cramps, pain, paresthesias, carpopedal spasm) -> Inc. PTH.
Calcium homeostasis: Dec. pH?
Dec. pH (more H+) -> albumin binds less Ca2+ -> Inc. ionized Ca2+ -> dec. PTH.
PTH secretion induced by:
Dec. Ca2+
Dec. Mg2+
Dec. 1,25(OH) D3
Inc. PO4-
CaMPeD
PTH secretion inhibited by:
Very low Mg2+
Inc. 1,25(OH) D3
Dec. Mg2+ caused by:
Diarrhea Aminoglycosides Diuretics Alcohol abuse. DADA!
25 (OH) D3 -> 1,25 (OH) D3 conversion induced by?
High PTH
Low PO4-
“induced by a high and a low P”
Functions of thyroid peroxidase include:
Oxidation
Organification of iodide
Cupling of monoiodotyrosine (MIT) and diiodotyrosine (DIT).
Wolff-Chaikoff effect-
Excess iodine temporarily turns off thyroid peroxidase - dec. T3 & T4 production (protective autoregulatory effect).
T3 functions in general:
“Energy for work and growing”