Epinephrine and norepinephrine
They are also called as adrenaline and noradrenaline.
Synthesis:
They are synthesized from the amino acid tyrosine in the chromaffin cells of adrenal medulla. And they are released in response to fight and flight conditions.
Chemistry:
They are the derivatives of the amino acid tyrosine. Epinephrine differs from norepinephrine only in that epinephrine is methylated on primary amino group of aliphatic side chain as shown below:
Metabolic roles:
- Effect on metabolism:
- Epinephrine increases oxygen consumption and carbon dioxide removal and increases basal metabolic rate.
- It also increases blood sugar level by increasing glycogenolysis in liver.
- Also cause lipolysis.
- Effect on heart:
- Epinephrine increases overall activity of the heart i.e.
- Heart rate
- Force of contraction
- Conductivity in heart muscle.
- Effect on blood pressure:
- Increases systolic blood pressure by increasing the force of contraction and cardiac output.
- Effect on respiration:
- Increase the rate and force of respiration.