Background & Objective: It is reported that acute forced swimming stress induces analgesia immediately, and chronic stress induces hyperalgesia. Whereas in response to nociceptive stimulation, small-diameter C-fibers of the excitatory system in the dorsal horn of the spinal cord are activated, therefore, in the present study, the effects of C-fiber lesion in stress and dexamethasone-induced ana...

Inbred mouse lines selectively bred for divergent levels of swim induced analgesia were differed in the ability to escape electric footshock. Mice displaying a high analgesia on a hot plate, after swimming for 3 min at 20 degrees centigrade terminated electric current applied at ascending intensity to the grid floor at a higher value compared to the low analgesia line. The difference was partic...

Stress is known to produce analgesia. The pain threshold is altered in diabetes. We studied the effect of 1 hr of immobilisation stress on pain threshold in male Wistar rats. The same effect was tested in streptozotocin induced diabetic rats. The pain threshold of tail flick, vocalisation and vocalisation after discharge increased in the control group after the stress procedure. Significant ana...

Postoperative nitrogen balance was monitored in twelve patients undergoing hysterectomy under either epidural analgesia or general anaesthesia. The mean cumulative five-day nitrogen losses were significantly lower after epidural analgesia than after general anaesthesia. Nitrogen sparing presumably results from inhibiting the stress-induced release of catabolic hormones, since epidural analgesia...

Rat pups become immobile and analgesic when exposed to an adult male rat. The aim of this study was to determine whether these reactions are under the control of endogenous opioids and to determine the role of the midbrain periaqueductal gray (PAG), which mediates stress-induced immobility and analgesia in adult animals. In Experiment 1, 14-day-old rats were injected systemically with the gener...

Stress induced analgesia has been shown to utilise both non-opioidergic and opioidergic mechanisms. Earlier studies indicate that opiodergic analgesics exhibit corollary changes in blood glucose level. In this study, the changes in blood glucose level by swim induced stress and the influence of exogenous glucose administration on the stress induced antinociception were studied. Stress per se (b...

The neuropeptide orphanin FQ (also known as nociceptin; OFQ/N) has been implicated in modulating stress-related behavior. OFQ/N was demonstrated to reverse stress-induced analgesia and possess anxiolytic-like activity after central administration. To further study physiological functions of OFQ/N, we have generated OFQ/N-deficient mice by targeted disruption of the OFQ/N gene. Homozygous mice d...

It has been reported that morphine tolerance does not develop in the presence of chronic pain. Therefore, this study was conducted to find out whether chronic inflammatory pain is able to eliminate or attenuate the developed tolerance to analgesic effect of morphine and also to investigate the role of lumbar spinal cord as a candidate site for this interaction. Tolerance was induced in adult ma...