[Effect of intrathecal pumping morphine on immunological function in rats with formalin pain].
OBJECTIVE
To evaluate the immunological function in rats with formalin inflammatory pain through intrathecal pumping different dosages of morphine.


METHODS
Thirty-two Sprague-Dawley rats were randomly divided into 4 groups (n = 8 in each group): saline group (NS) and morphine group included M1 group (10 microg/h) , M2 group (5 microg/h), and M3 group (2.5 microg/h). Chronic intrathecal catheterization was performed under anesthesia with 10% chloral hydrate (300-350) mg/kg according to M2 group (5 microg/h) and M3 group (2. 5 microg/h). Chronic intrathecal catheterization was modified Yaksh's. After 7 days, pain intensity scoring (PIS) was utilized to assess antinociceptive effect of morphine. And spleens were aseptically removed to obtain splenic cells. T lymphocyte function was evaluated based on Concanavalin-A induced splenocyte proliferation. A modified lactic acid dehydrogenase release assay was used to assess NK cell activity. Phenotypic expression of cell surface markers of T lymphocyte subsets (CD3+, CD3+ CD4+, CD3+ CD8+, and CD4+ / CD8+ ) and NK cell ( CD161+) in the spleen were analyzed by flow cytometry.


RESULTS
Compared with the NS group, PIS of morphine group decreased obviously (P < 0.01) and was dose-dependent in the early and late phase of formalin pain, but there were no significant differences among morphine groups. Spleen index, splenocyte proliferation and NK cell activity were significantly suppressed by intrathecal pumping morphine. Phenotypic expression of T lymphocyte subsets and NK cell assessed by flow cytometry were different from the control group in all morphine groups.


CONCLUSIONS
There was significant antinociception of intrathecal pumping morphine. After intrathecal pumping different dosages of morphine (10 microg/h,5 microg/h, and 2.5 microg/h), the function of cellular immunity was suppressed and was dose-dependent.
Zou
Wang-yuan
WY
Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha 410008, China. zwyfeng@163.com
Guo
Qu-lian
QL
Wang
E
E
Cai
Jin
J
D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D007278:Injections, Spinal; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D010146:Pain / Q000139:chemically induced / Q000276:immunology*; D010147:Pain Measurement; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D016176:T-Lymphocyte Subsets / Q000276:immunology
D000701:Analgesics, Opioid; D007166:Immunosuppressive Agents; D005557:Formaldehyde; D009020:Morphine