Abstract ID: A8

Abstract Title: Effect of sympathectomy on streptozotocin induced neuropathic pain in rats

Poster Type: Either


ABSTRACT BODY

Introduction:
Pain and peripheral neuropathy are significant complications of diabetes in patients and streptozotocin induced diabetic rats (STZ). The association between the sympathetic nervous system and the underlying mechanism of this type of pain is not clear, even though the pain that occurs in patients with diabetic neuropathy may be similar to sympathetically mediated pain. Thus, the purpose of the present study was to investigate if lumbar sympathectomy prevents or reduces the mechanical allodynia induced by streptotozocin in rats.

Methods:
This protocol was approved by our institutional animal care committee. After collecting baseline pain threshold data using von Frey filaments were collected, N=23 Male Sprague-Dawley rats were divided into two groups. Under general anesthesia with Phenobarbital. Group I (N=12) rats underwent transabdominal surgical bilateral lumbar sympathectomy. Eight days later, they received 55 mg/kg intraperitoneal injection of streptozotocin (STZ). Group II (N=11) rats received the same dose of STZ without undergoing surgery. Then pain threshold measurements were repeated at 4, 7, 10, 14 and 28 days after STZ injection. Data were analyzed with Students t- test after ANOVA. * indicates P<0.05 compared to baseline.

Results:
The results of our study are summarized in the figure (table 1) below. All the animals developed the typical neuropathic pain behavior within 10 days after STZ injection and 3 days after rats developed hyperglycemia. The decrease in pain threshold remained decreased in both groups through out the experimental period.

Conclusions:
Our finding clearly demonstrates reduction in pain threshold, which is frequently seen in diabetic patients. However, surgical lumbar sympathectomy before inducing diabetes in rats did not alter mechanical allodynia.

ATTACHED FILES

A8_ABS ASRA Table 1 Effect of sympathectomy on streptozotocin induced neuropathic pain in rats.doc





Reg Anesth Pain Med 2004; 29(2):A8