環境豐富化對大鼠傷口癒合之影響

實驗鼠之飼養環境系統及社交方面，會影響動物的生理、情緒及行為，豐富化的飼養環境可以改善大鼠的身心健康。本研究目的是評估環境豐富化（EE）在大鼠疼痛壓力下，其下視丘 – 腦下垂體 – 腎上腺軸對傷口癒合、生理和賀爾蒙變化之影響。本研究中，將3週齡雄性大鼠（Sprague-Dawley）圈養在IVC籠中，每籠2隻動物，並分成一般組（對照）和EE飼養組，飼養至11–12週齡且體重達400克時，開始進行傷口癒合測定。實驗分為測試實驗及驗證實驗二種階段，測試實驗：手術期間用4 – 5％的Isoflurane麻醉大鼠，並將背部皮膚切除至1 × 1 cm2正方形，每天記錄傷口範圍連續7天，並在第7天進行組織學檢查，在傷口切除後0、1.5、3、24和72小時時，量測血液中促腎上腺皮質激素(ACTH）和皮質酮（CORT）的濃度；驗證實驗則用5％的Sevoflurane麻醉大鼠並用Biopsy punch 取0.8 × 0.8 cm2之傷口，每天記錄傷口範圍至傷口完全癒合(連續18天)，並在第18天進行組織學檢查，Hormone濃度量測時間與測試實驗相同。本實驗也通過RGS（Rat Grimace Scale）系統測量實驗大鼠的疼痛指數。結果顯示，在4次的實驗中，EE組及CTL組之ACTH和CORT激素濃度的倍率變化、傷口癒合速率及病理組織方面，並沒有如預期飼養在環境豐富化的大鼠之傷口癒合速度優於飼養在一般標準環境裡的大鼠，實驗組與對照組之間沒有呈現顯著性差異。從影像監視紀錄系統觀察到一個現象：實驗期大鼠，在CTL組大鼠之互動、社交行為(互舔傷口行為)較EE組之大鼠多；EE組的大鼠有較多的時間在探索環境物件上，彼此間互動、社交、互舔整理傷口之時間反而較少。本研究推論：環境豐富化對實驗動物的社交行為影響較大，對於病理生理變化的傷口癒合影響較小。

關鍵字

囓齒動物；環境豐富化；動物福祉； HPA軸； ACTH ； CORT ；傷口癒合；社交行為； RGS（Rat Grimace Scale）

並列摘要

Environment and social aspects of the feeding environment affect the physiology, mood and behavior of the animals. Rich feeding environment can improve the physical and mental health of the rats. The aim of this study was to evaluate the effect of environmental enrichment (EE) on wound healing, the physiological events, and hormone evolution of hypothalamic-pituitary -adrenal axis(HPA) during the pain stress in rats. In our study, 3 weeks old male rats (Sprague-Dawley) were housed in IVC cages, 2 animals per cage, and separated into the conventional (control) and EE feeding groups. When the rats were reared to 11-12 weeks old and weighing to 400 g, then introduced to wound healing assay. The experiment is divided into two types: test experiment and experimental verification. The rats were anesthetized with 4 - 5% Isoflurane during surgery of test experiment. The wound was excised into the 1 x 1 cm2. The wound area was recorded every day during 7 days, and histological examination was performed at the seventh day. The concentration of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) in blood was determinate at 0, 1.5, 3, 24, and 72 hours after wound excision. The rats were anesthetized with 5% Sevoflurane during surgery of experimental verification. And the wound was excised into the 0.8 x 0.8 cm2 that with a Biopsy punch. The wound area was recorded every day during 18 days, and histological examination was performed at the 18th day. The hormone concentration is the same as the test experiment. Moreover, the pain index of the experimental rats was measured by RGS (Rat Grimace Scale) system. In our results, there was no significant difference between the experimental and the control group, such as the body weight, fold change of ACTH and CORT in blood level, wound healing and histological examination. We observed the event that the social behavior of the CTL group (such as licking wounds) was more than the EE group, Because the EE group had more time to explore the environmental objects, therefore the social interaction and the behavior of licking each other were reduced. The social behavior of experimental animals maybe can affect the extent of wound healing more than environmental enrichment.

並列關鍵字

Rodent ； Environmental Enrichment ； Wound healing ； Animals Welfare ； Social interaction ； RGS (Rat Grimace Scale) ； ACTH ； CORT ； Hypothalamic–pituitary–adrenal axis