Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double-blind studies using 'inhibitory' or 'sensitizing', physiological test paradigms in healthy human ...

A number of clinical studies in which early adversities were defined retrospectively, demonstrated that early adverse experiences increased the morbidity rate of post-traumatic stress disorder (PTSD) in later life. However, no prospective studies have yet been conducted to elucidate whether early adversity affects the risk or severity of PTSD. Thus, we examined whether early adversity would str...

BACKGROUND An acupuncture treatment can reduce pain sensitivity in patients with chronic whiplash associated disorders (WAD). But it has been hypothesized that many of the experimental results in acupuncture research could be interpreted as stress-induced analgesia. OBJECTIVE The present study aimed at examining whether acupuncture has an effect on the autonomic nervous system response in pat...

Stress induced analgesia (SIA) is well known, but the reverse phenomenon, hyperalgesia is poorly documented. This study investigated the role of the histaminergic system in restraint stress hyperalgesia in rats, using thermal stimulation method (hot plate and tail flick tests). Paw licking and tail withdrawal latencies were taken before and after restraint for about one hour. Significant decrea...

background: morphine and lidocaine are known to influence the perception of pain. the present study sought to determine the influence of local administration of morphine on lidocaine-induced analgesia in morphine non-dependent (mnd), morphine dependent (md) and morphine withdrawal (mw) animals. methods: adult male wistar rats were divided into four groups: control, mnd, md and mw rats. lidocain...

The exposure of animals to a variety of stressful events can induce behavioral and physiological responses, which can be modulated by anxiety levels. It is well recognized that genetic factors play a substantial role in both anxiety and stress reactivity. The present study examined the effect of exposure to 2,4,5-trimethylthiazoline (TMT), a component of fox feces, on nociception and corticoste...

asthma is one of the fastest growing syndromes in many countries and is adding a huge cost to the health care system. increasing reports have linked airway infectious diseases to asthma. influenza is one of the most serious airway infectious diseases and in recent years there have been some serious influenza virus pandemics which caused increased fatality in numerous different populations. dive...

Growing evidence suggests that parasite-infected prey is more vulnerable to predation. However, the mechanism underlying this phenomenon obscure. In small mammals, analgesia induced by environmental stressors a fundamental component of defensive repertoire, promoting responses. Thus, reduced may impair ability and increase their predation risk. This study aimed determine whether coccidia infect...