Classes of Catecholamines

1. Classes of Catecholamines By Tanya Mizani

2. Outline • A: Introduction • 1. What are catecholamines are what are the three different classes of catecholamines • 2. Catecholamines and Stress • 3. Locations of the three catecholamines • B: Dopamine • 1. Structure and chemical formula • 2. Function and importance of dopamine in the human body. • 3. Functions of dopamine cont… • 4. IR of Dopamine • C: norepinephrine • 1. structure and chemical formula. • 2. function and importance of norepinephrine on the body • 3. Synthesis of norepinephrine • 4. IR of norepinephrine • D: epinephrine • 1. structure and chemical formula • 2.function and importance of epinephrine in the body • 3. how epinephrine is synthesized • 4. IR of epinephrine • E: synthesis • 1.Synthesis of Dopamine, Epinephrine and Norepinephrine • F: Conclusion

3. What are catecholamines? • Catecholamines are : • chemical compounds derived from the amino acid tyrosine that act as hormones or neurotransmitters. • examples of phenethylamines. • soluble thus are able to circulate dissolved in blood. • There are three catecholamines that are more abundant than the rest: • dopamine • norepinephrine • epinephrine

4. Catecholamines and Stress • Catecholamines levels in blood are associated with stress. • Catecholamines cause general physiological changes that prepare the body for physical activity (e.g. exercise). • Some typical effects are increases in • heart rate • blood pressure • blood glucose levels • Some drugs, like selegiline, raise the levels of all the catecholamines.

5. Locations of the three catecholamines • Catecholamines are substances produced by nerve tissue (including the brain) and the inner part of the adrenal glands. • The adrenal glands produce large amounts of catecholamines as a reaction to stress.

6. Dopamine: structure and chemical formula • Dopamine has the chemical formula (C6H3(OH)2-CH2-CH2-NH2). • Its chemical name is 4-(2-aminoethyl)benzene-1,2-diol and it is abbreviated "DA • The melting point of dopamine is between 218 and 220 degrees.

7. Dopamine: function and importance of dopamine in body • Role in movement: • Dopamine is critical to the way the brain controls our movements • crucial part of the a motor basal ganglia loop. • Shortage of dopamine, particularly the death of dopamine neurons in the nigrostriatal pathway, causes Parkinson's disease, in which a person loses the ability to execute smooth, controlled movements. • Role in Cognition and Frontal Cortex Function: • In the frontal lobes, dopamine controls the flow of information from other areas of the brain. • Dopamine disorders in this region of the brain can cause a decline in neurocognitive function, particularly those linked to memory, attention and problem solving.

8. Functions of dopamine cont. • Role in pleasure and motivation: provides feelings of enjoyment to motivate us to do certain activities • Dopamine is known to be released when unpleasant or aversive stimuli are encountered, suggesting that it is not only associated with 'rewards' or pleasure. • The firing of dopamine neurons occur when a pleasurable activity is expected, regardless of whether it actually happens or not. This suggests that dopamine may be involved in desire rather than pleasure. • Drugs that are known to reduce dopamine activity (e.g. antipsychotics) have been shown to reduce people's desire for pleasurable stimuli. It seems that these drugs reduce the 'wanting' but not the 'liking', providing more evidence for the desire theory.

9. Norepinephrine: structure and chemical formula • The chemical formula is C8H11NO3.

10. Function and importance of norepinephrine in the body • The central functions of norepinephrine (NE) are: • regulation of alertness and of the wakefulness-sleep cycle, • maintenance of attention, memory and learning, • cerebral plasticity and neuro-protection. • It is one of the 'stress hormones' and affects parts of the human brain where attention and impulsivity are controlled. • This compound affects the fight-or-flight response, activating the sympathetic nervous system to • directly increase heart rate • release energy from fat • increase muscle readiness

11. Epinephrine: structure and chemical formula • The chemical formula of epinephrine is C9H13NO3. • Melting point of epinephrine is 215 degree celsius. • Water solubility is <0.01 g/100 mL at 18 C .

12. Function of Epinephrine • Plays a central role in the short-term stress reaction—the physiological response to conditions that threaten the physical integrity of the body. • Secreted by the adrenal medulla. • When released into the bloodstream, causes many diverse occurrences by binding to multiple receptors in the body. • Acts to increase heart rate and strength of contractions and dilate the pupils. Constriction of blood flow restricts blood flow in arterioles in the skin and gut. Vessels dialate in the arterioles of the leg muscle. • Breaks down glycogen and synthesizes glucose in the liver cells for energy and begins the breakdown of lipids in fat cells. • Elevates the blood sugar level (by increased hydrolysis of glycogen to glucose), and redistribute blood flow away from the skin and inner organs.

13. Synthesis of Dopamine, Epinephrine and Norepinephrine

14. Conclusion • The three catecholamines work together to: • Make sure the stress levels are right • Help with the hormonal levels. • Depriving the body of them could have dire results.

15. References • http://en.wikipedia.org/wiki/Catecholamine • http://www.neurosci.pharm.utoledo.edu/MBC3320/dopamine.htm • Mcmurry book. • Kaplan GRE biology • Van Gaalen MM, Brueggeman RJ, Bronius PF, Schoffelmeer AN, Vanderschuren LJ. “Behavioral disinhibition requires dopamine receptor activation”. Psychopharmacology (Berl). 2006 Apr 25