Epinephrine
Nor-epinephrine
Dopamine
--- Content provided by FirstRanker.com ---
Adrenal medulla is a sympathetic ganglion in
which the post ganglionic neurons have lost
--- Content provided by FirstRanker.com ---
their axons and become secretory cellsCatecholamines
PNMT is found in brain and adrenal medulla
--- Content provided by FirstRanker.com ---
Adrenal PNMT is induced by glucocorticoidsAfter hypophysectomy, epinephrine
concentration decreases
--- Content provided by FirstRanker.com ---
In 21 -hydroxylase deficiency adrenal
medulla is dysplastic
Catecholamines
--- Content provided by FirstRanker.com ---
95% dopamine and 70% Nor-epinephrine
and epinephrine is conjugated to sulfate
--- Content provided by FirstRanker.com ---
On standing the levels of free nor-epinephrine increases by 50-100%
After adrenalectomy, plasma nor-
--- Content provided by FirstRanker.com ---
epinephrine levels remain unchanged but
free epinephrine level falls
Catecholamines are stored in granules with
--- Content provided by FirstRanker.com ---
ATP
Granules also contain chromogranin A,
--- Content provided by FirstRanker.com ---
opioid peptidesAdrenomedullin is also found
Regulation of catecholamines
--- Content provided by FirstRanker.com ---
Reduced in sleepIncreased in emergency situations
W.B.Cannon called it " The emergency
function of sympathoadrenal system"
--- Content provided by FirstRanker.com ---
Drugs
NE is increased by emotional stresses with
which the individual is familiar
--- Content provided by FirstRanker.com ---
Epinephrine rises in stresses due to
unexpected situation
--- Content provided by FirstRanker.com ---
Effects of CatecholaminesIncreases glycogenolysis in liver and
skeletal muscles
--- Content provided by FirstRanker.com ---
Increases insulin and glucagon secretion by
- adrenergic mechanisms
--- Content provided by FirstRanker.com ---
Decreases insulin and glucagon secretionby - adrenergic mechanisms
Increases FFA mobilization
--- Content provided by FirstRanker.com ---
Increases plasma lactatesStimulates metabolic rate
Effects of Catecholamines
NE and Epinephrine both increase rate and
--- Content provided by FirstRanker.com ---
force of myocardial contraction
Increases myocardial excitability
Can lead to extrasystoles and arrythmias
--- Content provided by FirstRanker.com ---
NE produces vasoconstrictionEpinephrine causes vasodilatation
Effects of Catecholamines
Catecholamines increase alertness
--- Content provided by FirstRanker.com ---
Increases metabolic rate due tovasoconstriction and lactate oxidation
When injected increases potassium levels
--- Content provided by FirstRanker.com ---
and later decreases
Dopamine causes renal and mesenteric
--- Content provided by FirstRanker.com ---
vasodilatationElsewhere DA causes vasoconstriction
DA has positive inotropic effect on heart
DA is useful in treatment of shock
--- Content provided by FirstRanker.com ---