[Expression of beta-endorphin and micro-opioid receptor during wound healing process in rat with deep partial-thickness scald].
OBJECTIVE
To observe the expression of beta-endorphin and micro-opioid receptor (MOR) during wound healing process in rat with deep partial-thickness scald.


METHODS
Thirty-six Wistar rats were randomly divided into control( n = 6, without treatment) , and scald ( n = 30, with 5% TBSA deep-partial thickness scald) groups. Skin specimens from wound were harvested immediately after scald and on 3, 7, 14, 21 post-scald days( PSD) for the determination of 1-endorphin and MOR expression with immunofluorescent staining.


RESULTS
beta-endorphin and MOR were mainly distributed in nerve terminal at the border of dermis and epidermis , keratinocyte in some epidermis , in the fibroblast in dermis , with a weak expression The expression of beta-endorphin peaked in whole layer of skin on 3 PSD( 196 +/-16, P <0. 01) ,while that of MOR was concentrated in keratinocytes in the basal layer and the basement membrane. The expression of MOR was strengthened on 7 PSD with disarrangement of collagen , and it peaked on 14 PSD (306 +/- 23, P < 0.01) with epithelization in some wounds. There was still strong expression of beta-endorphin on 7 and 14 PSD. Complete epithelization was observed in scald group on 21 PSD, with nerve terminal approaching the boundary between the dermis and epidermis, and collagen began to arrange in good order. The expression of P-endorphin in scald group (31 +/-24)was similar to that in control group(30 +/- 18) on 21 PSD, but the expression of MOR (56 +/- 16) was still higher than that in control group (28 +/- 15 ).


CONCLUSIONS
The expression of MOR and P-endorphin exhibits chronobiological nature during the process of wound healing,
Cheng
Biao
B
Department of Plastic Surgery, Guangzhou General Hospital of Guangzhou Military Command , Guangzhou 510010, PR China.
Liu
Hong-wei
HW
Fu
Xiao-bing
XB
Sheng
Zhi-yong
ZY
Qiu
Jian-yong
JY
Cao
Rong
R
D000818:Animals; D002056:Burns / Q000378:metabolism*; D004195:Disease Models, Animal; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D014945:Wound Healing; D001615:beta-Endorphin / Q000378:metabolism*
D017450:Receptors, Opioid, mu; D001615:beta-Endorphin