Hemorrhagic shock is accompanied by an increase in endogenous opioid peptides release, both in the central nervous system and in the peripheral tissues. Complex central opioid mechanisms play an essential role in regulation
of cardiovascular centre function since activation of µ and blockade of δ1 central opioid receptors inhibit the initiation of the sympathoinhibitory phase of regulation, while activation of κ receptors blocks the compensatory
cardiovascular responses to hemorrhage. The paper reviews the significance of peripherally released opioid peptides in haemorrhagic shock.
Peripheral opioid receptor blockade in hypovolemic shock results in the pressor effect due to the increase in total peripheral resistance and positive inotropic action. Moreover, abolition of endogenous opioid peptides action
reduces the disturbances in acid-base balance through the influence on hormone secretion and prevents microcirculatory dysfunction.

Keywords: haemorrhagic shock, Opioid Peptides, peripheral regulatory mechanisms