Impact of chronic nicotine on sciatic nerve injury in the rat

Abstract

Chronic nicotine exposure and the immune response to peripheral nerve injury has not been investigated thoroughly. Rats were exposed to chronic nicotine or saline followed by chronic constriction injury (CCI) of the sciatic nerve. Mechanical sensitivity was measured at various time points and the immune response was investigated at 21 days post-CCI. Chronic nicotine increased mechanical hypersensitivity, microglia activation, and the production of IL-1β, but not the number of immune cells at the site of injury. These results suggest that chronic nicotine increases mechanical hypersensitivity following peripheral nerve injury through a mechanism that may involve an increased production and release of central and peripheral cytokines.

Smoking and Pain

“…67,75,77,78 Compared with nicotine-naïve rats, nicotine-tolerant rats develop greater mechanical hyperalgesia after spinal nerve ligation or sciatic nerve injury. 79,80 The increased mechanical hyperalgesia was associated with increased spinal dynorphin levels 81 as well as increased production of cytokines centrally and peripherally. 79 Thus, when evaluating the behavioral effects of chronic nicotine exposure a complex interplay among receptor desensitization, overexpression, and neural plasticity in associated nociceptive pathways must be considered.…”

“…79,80 The increased mechanical hyperalgesia was associated with increased spinal dynorphin levels 81 as well as increased production of cytokines centrally and peripherally. 79 Thus, when evaluating the behavioral effects of chronic nicotine exposure a complex interplay among receptor desensitization, overexpression, and neural plasticity in associated nociceptive pathways must be considered. Furthermore, nicotine withdrawal was associated with hyperalgesia in nicotine-tolerant rodents, 57,82,83 which was reversible by morphine administration.…”

Effect of Combined Nicotine and Shrapnel Exposure on Pain Measures and Gait After Nerve Injury

“…12 One study conducted by Josiah and Vincler 13 suggest that chronic nicotine exposure increases the sensitivity of normal rats to mechanical pressure and compounds nerve injury-induced mechanical hypersensitivity following peripheral nerve injury . Also, in an additional study conducted by Brett et al, 14 it was reconfi rmed that the presence of chronic nicotine further increased nerve injury-induced mechanical hypersensitivity in the periphery. Thus, studies have shown that tobacco possess many negative effects on the healing of many types of tissues and this is of major concern because of the increasing use of tobacco products among the American population.…”

Cigarette Smoking Is Associated With Cubital Tunnel Syndrome

“…The reason why cigarette smoking is associated with CubTS is unclear. Numerous studies have suggested that cigarette smoking is associated with peripheral nerve dysfunction . Nicotine has been shown to worsen the effects of ischemia in various tissues through its toxic effects, and it may impair recovery following peripheral nerve injury .…”