Endogenous opioid system
Opioidmotif
Tyr-Gly-Gly-Phe-(Met/Leu)
- DOR –  opioid receptor
- KOR –  opioid receptor
-MOR –  opioid receptor
-NOR – N/OFQ opioid receptor
Endorfins
- Alpha, beta, gamma and delta
- hypophysis / hypothalamus and elsewhere
- Strenuous exercise / physical activity, pain, orgasm
- Analgesia and feelings of "well-being„
- Immune system mobilization?
- Creating emotional connections
- Food intake
- The same effect for pain but different for stress
 / 
Enkephalins
- Met-/Leu-
CNS sites associated with pain perception, behavior, motor
control, and neuroendocrine function
- T cells, macrophages, mast cells
- Excitement, physical activity, sexual activity, fear
 / 
Dynorphins
- A and B
- Periaqueductal gray matter, medulla oblongata
- Parts of the spinal cord involved in pain transmission
- Hypothalamus, hippocampus, mesencephalon
- Mechanical and thermal hyperalgesia
 / 
Endomorphins
- 1 and 2
- Heterogeneous distribution in the CNS
- Antinociceptive function
- NO-mediated vasodilation

Nociceptin/orphanin FQ
- Hippocampus, cerebral cortex, spinal cord
- It triggers hyperalgesia and allodynia by reversing opioid-induced
analgesia
- Behavior, drug addiction
- Cardiovascular system - hypotension / bradycardia
NOP
Physiological functions
- Stress – connection between b-endorphin and
ACTH
- (+) food intake, effect on food "palatability"
- (-)/(+) concentration-dependent fluid intake
- GIT – inhibition of neurotransmitter release constipation
/ reduction of motility
- Renal functions (-) – inhibition of diuresis (), (-)resorption
of water()
- memory
- Emotions, mood (+) euphoric effect
- Sexual behaviour – rather (-), (-) socio-sexual
interactions BUT increase sexual arousal and
motivation
- Parturition?
Physiological functions
- Respiration
- Suppression of respiratory neuron activity - bradypnoea?
- Respiration in stress conditions, protective functions in hypoxia and
hypercapnia
- Cardiovascular functions
- inhibitory
- They reduce HF and BP BUT it depends on the situation!
- Immune functions
- Dual effect depending on a number of factors
- Possible protection against cancer?
Endocannabinoid system
Cell-based
model of
coagulation