Neuroprotective Effect of Naloxone in Inflammation-Mediated Dopaminergic Neurodegeneration - Drugs of Abuse: Neurological Reviews and Protocols - page 43

Fig. 1. Structures of morphine and naloxone stereoisomers. Numbers in parentheses
indicate the approximate affi nity to µ -type opioid receptor.

exclusively related to the opioid system. The notion of nonopioid actions
of naloxone are discussed further toward the end of this chapter. Closer
examination, at the molecular and cellular levels, of those disease conditions
seems to suggest the existence of a common theme: the involvement of immune
activities, in particular, the infl ammatory responses.

3. Role of the Infl ammatory Process in Ischemia, Brain
and Spinal Cord Injuries, and Sepsis
Recently, increasing evidence has implicated the involvement of the infl am-
matory process in the pathogenesis of a variety of diseases. For example, in
ischemic brain injury, the infl ammatory response can be induced by the initial
phase of neuronal death triggered by excitotoxicity. Cytotoxic factors produced
as a result of the infl ammatory response are thought to exacerbate the neuronal
damage in the later phase of disease progression (24-26) . Similarly, in the
case of myocardial tissue injury, a cell death induced infl ammatory response is
also suspected of playing a role in the fi nal outcome of the disease (27 , 28) . An
equally interesting issue is the realization of an infl ammatory response induced
by damage to the peripheral and central nervous systems. Again, it is thought