Gender differences in paclitaxel-induced neuropathic pain behavior and analgesic response in rats.
10.4097/kjae.2012.62.1.66
- Author:
Boo Young HWANG
1
;
Eun Soo KIM
;
Chul Hong KIM
;
Jae Young KWON
;
Hae Kyu KIM
Author Information
1. Department of Anesthesia and Pain Medicine, Pusan National University School of Medicine, Busan, Korea. hakykim@pusan.ac.kr
- Publication Type:Original Article
- Keywords:
Ketamine;
Mechanical allodynia;
Morphine;
Paclitaxel;
Rat;
Sex differences
- MeSH:
Analgesics;
Animals;
Female;
Humans;
Hyperalgesia;
Injections, Intraperitoneal;
Ketamine;
Male;
Morphine;
Neuralgia;
Paclitaxel;
Rats;
Rats, Sprague-Dawley;
Sex Characteristics
- From:Korean Journal of Anesthesiology
2012;62(1):66-72
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Females show greater sensitivity than males to several modalities of experimental pain. However, the gender differences in paclitaxel-induced neuropathic pain have not been studied. The current study examined the gender differences in neuropathic pain behavior and the effect of analgesics in a paclitaxel-induced neuropathic pain model in rats. METHODS: Neuropathic pain was induced by intraperitoneal injection of paclitaxel (2 mg/kg) on 4 alternate days in Sprague-Dawley rats of both genders. Mechanical allodynia was measured using a von Frey filament. The gender differences in analgesic responses were determined after administration of morphine (2 or 5 mg/kg), ketamine (2 or 5 mg/kg), or combined morphine (2 mg/kg) and ketamine (2 mg/kg). RESULTS: Paclitaxel induced mechanical allodynia, which began to manifest on day 4, peaked within 10 days, and plateaued for at least 2 months after the first paclitaxel injection. No gender difference in the manifestation of mechanical allodynia was observed. A 2 mg/kg dose of ketamine increased the mechanical threshold only in males. The 5 mg/kg dose of ketamine significantly increased the mechanical threshold in both genders. Morphine (2 and 5 mg/kg) dose-dependently increased the mechanical thresholds in both genders. The 2 mg/kg dose of ketamine enhanced the antinociceptive effect of 2 mg/kg morphine only in females. CONCLUSIONS: No gender difference in paclitaxel-induced neuropathic pain or analgesic response to ketamine or morphine was observed in Sprague-Dawley rats. Low dose ketamine enhanced the analgesic effect of morphine on paclitaxel-induced mechanical allodynia but only in female rats.
