Chap 48 -Substance P and endorphin

B9902014 吳瑞當B9902050 郭柏彥

Substance P

endorphin

Introduction• Substance P(SP) 1.released from the terminals of sensory n

erve cells of skin and joints– a kind of neurotransmitter– transmits pain information to the CNS

2.the receptor is NK1(GPCR). 3.controlls emotion.

• Endorphins (endogenous morphine)–morphin produced naturally in the body

1.hypothalamic neurons generate and pituitary gland release– a cleavage product of pro-opiomelanocortin (POMC) – the precursor hormone for adrenocorticotrophic

hormone (ACTH)2. μ opioid receptors are the main receptor

3.modulating pain, cardiac, gastric, vascular function, panic and satiation– inhibit the release of the inhibitory neurotransmitter GABA– disinhibit the dopamine pathways– causing more dopamine to be released and cause inappropriate dopamine release, which

causes addiction

• Stimuli for Substance P secretion–mood disorders, anxiety, stress,

reinforcement, neurogenesis, respiratory rhythm, neurotoxicity, nausea/emesis, painand nociception.

• Stimuli for endorphins secretion–Strenuous exercise, Excitement,

Pain, DeathOrgasm, Over exposure to sun, Spicy food

Endorphins’Activity

• Relaxationprofound relaxation in a float tank triggers the production of endorphins, which explains the pain relief experienced during float sessions.

• Acupuncture– inserting acupuncture needles into

specific body points triggers the production of endorphins–higher levels of endorphins were

found in cerebrospinal fluid

Endorphins’ Activity

• PregnancyA placental tissue of foetal origin(the syncytiotrophoblast)excretes beta-endorphins into the maternal blood system from the 3rd month of pregnancy. Foetuses make their mothers endorphin-dependent then manipulate them to increase nutrient allocation to the placenta.