- Epinephrine and Norepinephrine
- Epinephrine is an adrenal hormone (AKA: Adrenalin)
- Norepinephrine is nitrogen-containing neurotransmitter (AKA:
- found in parts of the sympathetic and central nervous system
- Responds to 'Fight or Flight'
- Act through adrenergic receptors
- alpha-1, alpha-2, beta-1, beta-2, beta-3
- Increased gluconeogenesis in liver
- Increased glycogenolysis in liver and muscle
- Increased lipolysis in adipose tissue
- induces muscle anaerobic glycolysis
- increases lipolysis but decreases fat oxidation so that overall
effect may be an increase in body fat (Coyle Ed, Austin Group
- Blood sugar regulation
- Anti-inflammatory action
- Immune response modification
- Heart and blood vessel toning
- Central nervous system stimulation
- Stress reaction normalization
Cortisol is a catabolic hormone which induces
the breakdown of cellular proteins. Cortisol helps maintain plasma
glucose levels during a fast, by stimulating gluconeogenesis
/ lipolysis and inhibiting lipid synthesis. Glucocorticoids decrease
muscle protein synthesis and increase muscle protein degradation
so amino acids will be available for glucose production.
Cortisol also increases whole body lipolysis, in part, by
enhancing GH and catecholamine stimulated lipolysis, yet chronic
hypercortisolemia results in increased fat mass (Samra 1998).
Cortisol increases as intense exercise is prolonged (Di Pasquale,
1992c). In men, significant elevations in cortisol seem to reduce
endogenous testosterone by acting directly upon the testis to
impair the biosynthesis of testosterone (Di Pasquale, 1992c).
Submaximal exercise at lower intensities (i.e. 63% maximum oxygen
consumption) stimulates lower cortisol response than higher intensities
(i.e. 86% maximum oxygen consumption) (Farrell, Garthwaite, &
Gustafson, 1983; Naveri, 1985).
Cortisol increases whole body lipolysis
- Regulation of sodium, potassium and fluid volume
- Increase of aldosterone results in sodium and water retention
and potassium excretion
- Keeps blood pressure from falling
- Maintains electrolyte balance and cell hydration
Dehydroepiandrosterone is steroid prohormone produced from
cholesterol by the adrenal glands, the gonads, adipose tissue,
brain and in the skin (by an autocrine mechanism). DHEA is the
precursor of androstenedione which can undergo further conversion
to produce testosterone and estrogens.