The Study On The Effects And Mechanism Of Abdominal Surgery On The Rabbit’s Microvascular Albumin Leakage

Objective:This thesis explores the Effects and possible mechanism of the postoperative rabbit’s microvascular albumin leakage by observing the phenomenona of the early postoperative mesentery microvascular albumin leakage and the change of endothelial gaps in the lung, the mesentery, and the microvascular intestinal mucosa as well as testing the leakage rate of mesentery microvascular albumin and the concentration of serum albumin and the serum inflammation mediators on the rabbits with abdominal surgery.Methods:Thirty-six Japanese big-eared rabbits were randomly divided into the control group (six rabbits) and the surgery group (6h,12h,24h,48h,72h. six ones each group). The control group did not undergo the surgery while the treatment group received subtotal gastrectomy and distal pancreatectomy with splenectomy. All the postoperative rabbits were nourished by equal calorie and nitrogen. Glucose and fat offered70%and30%of the calories respectively. The ratio of nitrogen and calorie was1:130. The concentration of serum albumin. IL-6.TNF-α,IL-2.ICAM-1,VEGF and HIS were detected at each preoperative and postoperative checkpoint:with mainlining RBITC labeled BSA. mesentery microvascular albumin leakage of the rabbit was observed dynamicly by laser sacanning confocal microscope and its microvascular serum albumin leakage ratio was calculated; the change of endothelial gaps in microvascular of the lung, the mesentery, and the intestinal mucosa was detected through transmission electron microscope. Results:1. The change of serum albumin concentration:①Comparison within each surgery group:There was a signiicant difference between the preoperative and the postoperative (6h,12h,72h) concentration (P<0.05). A highly significant differencewas also found between the preoperative and the postoperative (24h.48h) concentration (P＜0.01).②Comparision between the groups:Before the surgery, there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). After the surgery, there was no significant differencebetween the6h group and the control group (P＞0.05);A significant differencewas found between the12h group and the non-operative group (P＜0.05):A higly significant differencewas also found between the24h,48h,72h group and the control group (P＜0.01).③A positive correlation was found between the variaties of preoperative and postoperative serum albumin concentration between postoperative albumin concentration.2. The comparison of the serum inflammation mediators:(1) Serum IL-6:①Comparison within each surgery group:There was a highly signiicant difference between the preoperative and the postoperative (6h.12h,24h,48h,72h) concentration(P＜0.01).②Comparision between the groups:Before the surgery. there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). After the surgery, a higly significant difference was found between the6h,12h,24h,48h,72h group and the control group (P＜0.01).(2) Serum TNF-α:①Comparison within each surgery group:There was a highly signiicant difference between the preoperative and the postoperative (6h,12h.24h,48h,72h) concentration(P＜0.01).②Comparision between the groups: Before the surgery, there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). After the surgery, a significant differencewas found between the6h group and the non-operative group(P＜0.05); A higly significant difference was also found between the12h,24h,48h,72h group and the control group (P＜0.01).(3) Serum IL-2:①Comparison within each surgen group:There was a highly signiicant difference between the preoperative and the postoperative (6h,12h,24h,48h) concentration(P<0.01); There was a signiicant difference between the preoperative and the postoperative (72h) concentration(P＜0.05).②Comparision between the groups:Before the surgery, there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). After the surgery, a significant differencewas found between the6h group and the non-operative group (P＜0.05):A higly significant difference was also found between the12h,24h,48h,72h group and the control group (P＜0.01).(4) Serum ICAM-1:①Comparison within each surgery group:There was a highly signiicant difference between the preoperative and the postoperative (6h,12h,24h,48h,72h) concentration(P<0.01).②Comparision between the groups:Before the surgery, there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). A higly significant difference was found between the6h,12h,24h,48h,72h group and the control group (P＜0.01).(5) Serum VEGF:①Comparison within each surgery group:There was a signiicant difference between the preoperative and the postoperative (6h.12h) concentration(P＜0.05):There was a highly signiicant difference between the preoperative and the postoperative (24h.48h.72h) concentration(P＜0.05).②Comparision between the groups: Before the surgery, there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). After the surgery, no significant differencewas found between the6h group and the non-operative group(P＞0.05); A higly significant difference was also found betweer the12h,24h,48h,72h group and the control group (P＜0.01).(6) Serum HIS:①Comparison within each surgery group:There was a highly signiicant difference between the preoperative and the postoperative (6h.12h,24h,48h,72h) concentration(P＜0.01).②Comparision between the groups:Before the surgery, there was no significant differencebetween the non-treatment group and the treatment group (P＞0.05). A higly significant difference was found between the6h.12h,24h,48h,72h group and the control group (P＜0.01)3. The comparison of the leakage rate of the rabbit’s mesentery microvascular:After the surgery, a significant difference (P＜0.05) was found between the6h group and the non-operative group; A higly significant difference (P＜0.01) was also found between the12h,24h,48h,72h group and the control group.4. The correlation between the leakage rate of microvascular albumin and the inflammation mediators IL-6、TNF-a.:A positive correlation (P＜0.01) was found between the variaties of the leakage rate of microvascular albumin and the concentration of IL-6、TNF-α.5. The change of microvascular endothelial gaps:In the control group, the membrane of endothelial cell was integrated and tightly jointed in microvascular of the lung, the mesentery, and the intestinal mucosa of the rabbit. In the treatment groups, there was an obvious cell swelling in microvascular of the lung, the mesentery, and the intestinal mucosa.0.2-0.5μm cell fissure appeared in normally tight junctions between the endothelial cells and some cell membranes were blebbing.Conclusion1. After the rabbit abdominal surgery, the concentration of serum albumin declined and came to the minimum in postoperative48h.2. Through laser sacanning confocal microscope, postoperative microvascular albumin leakage was observed and the leakage ratio peaked in48h. Under electron microscopy, the opening of the microvascular endothelial gap was found: It was inferred that the decrease in the concentration of albumin had relevance to the extravascular albumin leakage:3. After the rabbit abdominal surgery, the concentration of serum inflammation mediators (IL-6、TNF-α、IL-2、ICAM-1、VEGF、HIS) increase. A positive correlation was found between the variaties of the leakage rate of microvascular albumin and the concentration of inflammation mediators, whose leakage mechanism was possibly related to the activation of the postoperative inflammation mediators and the growing of the opening of microvascular endothelial gaps:4. A positive correlation was found between the variaties of preoperative and postoperative serum albumin concentration between postoperative albumin concentration, which illustrated that the higher the preoperative serum albumin concentration was, the wider differences between the albumin concentration were. Further research needs to be done to discuss whether serum albumin can be improved to an. ideal level before the surgery.