Effect of insulin-like growth factor I (IGF-I) administration on the healing of colonic anastomoses in rats

Cytoprotective gastric pentadecapeptide BPC 157 resolves major vessel occlusion disturbances, ischemia-reperfusion injury following Pringle maneuver, and Budd-Chiari syndrome

The stable gastric pentadecapeptide BPC 157 counteracts various venous occlusion-induced syndromes. Summarized are all these arguments, in the Robert’s cytoprotection concept, to substantiate the resolution of different major vessel occlusion disturbances, in particular ischemia-reperfusion injury following the Pringle maneuver and Budd-Chiari syndrome, which was obtained by BPC 157 therapy. Conceptually, there is a new point, namely, endothelium maintenance to epithelium maintenance (the recruitment of collateral blood vessels to compensate for vessel occlusion and reestablish blood flow or bypass the occluded or ruptured vessel). In this paper, we summarize the evidence of the native cytoprotective gastric pentadecapeptide BPC 157, which is stable in the human gastric juice, is a membrane stabilizer and counteracts gut-leaky syndrome. As a particular target, it is distinctive from the standard peptide growth factors, involving particular molecular pathways and controlling VEGF and NO pathways. In the early 1990s, BPC 157 appeared as a late outbreak of the Robert’s and Szabo’s cytoprotection-organoprotection concept, like the previous theoretical/practical breakthrough in the 1980s and the brain-gut axis and gut-brain axis. As the time went on, with its reported effects, it is likely most useful theory practical implementation and justification. Meantime, several reviews suggest that BPC 157, which does not have a lethal dose, has profound cytoprotective activity, used to be demonstrated in ulcerative colitis and multiple sclerosis trials. Likely, it may bring the theory to practical application, starting with the initial argument, no degradation in human gastric juice for more than 24 h, and thereby, the therapeutic effectiveness (including via a therapeutic per-oral regimen) and pleiotropic beneficial effects.

Glucagon-Like Peptide-2 Analogue ZP1849 Augments Colonic Anastomotic Wound Healing

Background

The enteroendocrine hormone glucagon-like peptide- (GLP-) 2 is a potent trophic factor in the gastrointestinal tract. The GLP-2 receptor (GLP-2R) is expressed in the stroma of the large bowel wall, which is the major therapeutic target area to prevent anastomotic leakage. We investigated the efficacy of the long-acting GLP-2 analogue ZP1849 on colonic anastomotic wound healing.

Methods

Eighty-seven male Wistar rats were stratified into four groups and received daily treatment with vehicle or ZP1849 starting one day before (day -1) end-to-end anastomosis was constructed in the left colon on day 0, and on days 0 (resected colon segment), 3, and 5, gene expressions of GLP-2R, Ki67, insulin-like growth factor- (IGF-) 1, type I (COL1A1) and type III (COL3A1) procollagens, cyclooxygenase- (COX-) 1, COX-2, and matrix metalloproteinase- (MMP-) 7 were quantified by RT-qPCR. Breaking strength, myeloperoxidase (MPO), transforming growth factor- (TGF-) β1, and soluble collagen proteins were measured on days 3 and 5.

Results

ZP1849 treatment increased Ki67 (P < 0.0001) and IGF-1 (P < 0.05) mRNA levels in noninjured colon day 0, and postoperatively in the anastomotic wounds compared to vehicle-treated rats. ZP1849-treated rats had increased (P = 0.042) anastomotic breaking strength at day 5 compared with vehicle. COL1A1 and COL3A1 mRNA levels (P < 0.0001) and soluble collagen proteins (P < 0.05) increased from day 3 to day 5 in ZP1849-treated rats, but not in vehicle-treated rats. COX-2 mRNA and MPO protein levels decreased from day 3 to day 5 (P < 0.001) in both groups. ZP1849 treatment reduced TGF-β1 protein levels on day 5 (P < 0.001) but did not impact MMP-7 transcription.

Conclusions

The GLP-2 analogue ZP1849 increased breaking strength, IGF-1 expression, and cell proliferation, which may be beneficial for colonic anastomotic wound healing.

Growth hormone abolishes the negative effects of everolimus on intestinal wound healing

AIM: To investigate whether the simultaneous treatment with human growth hormone (hGH) abolishes the negative effects of everolimus on anastomotic healing.

METHODS: Forty-eight male Sprague-Dawley-rats were randomized to three groups of 16 animals each (I: vehicle; II: everolimus 3 mg/kg po; III: everolimus 3 mg/kg po + hGH 2.5 mg/kg sc). Animals were pre-treated with hGH and/or everolimus daily for seven days. Then a standard anastomosis was created in the descending colon and treatment was continued for another seven days. The anastomosis was resected in toto and the bursting pressure was assessed as a mechanical parameter of intestinal healing. Moreover, biochemical (Hydroxyproline, PCNA, MPO, MMP-2 and MMP-9) and histological (cell density, angiogenesis, amount of granulation tissue) parameters of intestinal healing were assessed.

RESULTS: Anastomotic bursting pressure was significantly reduced by everolimus and a simultaneous treatment with hGH resulted in considerably higher values (I: 134 ± 19 mmHg, II: 85 ± 25 mmHg, III: 114 ± 25 mmHg; P < 0.05, I vs II; P = 0.09, I vs III and II vs III) Hydroxyproline concentration was significantly increased by hGH compared to everolimus alone (I: 14.9 ± 2.5 μg/mg, II: 8.9 ± 3.6 μg/mg, III: 11.9 ± 2.8 μg/mg; P < 0.05, I vs II/III and II vs III). The number of MPO-positive cells was reduced significantly by hGH compared to everolimus alone (I: 10 ± 1 n/mm², II: 15 ± 3 n/mm², III: 9 ± 2 n/mm²; P < 0.05, I vs II and II vs III), while the number of PCNA-positive cells were increased by hGH (I: 28 ± 3 /mm², II: 12 ± 3 /mm², III: 26 ± 12 /mm²; P < 0.05, I vs II and II vs III). Corresponding to these biochemical findings, HE-histology revealed significantly increased amount of granulation tissue in hGH-treated animals.

CONCLUSION: Inhibition of intestinal wound healing by everolimus is partially neutralized by simultaeous treatment with hGH. Both inflammation as well as collagen deposition is influenced by hGH.

Pharmacological interventions for improved colonic anastomotic healing: A meta-analysis

AIM: To identify pharmaceuticals for the prophylaxis of anastomotic leakage (AL), we systematically reviewed studies on anastomosis repair after colorectal surgery.

METHODS: We searched PubMed and EMBASE for articles published between January 1975 and December 2012. We included studies in English with the primary purpose of promoting healing of anastomoses made in the colon or rectum under uncomplicated conditions. We excluded studies on adverse events from interventions, nutritional interventions or in situ physical supporting biomaterials. The primary outcome was biomechanical strength or AL. We performed meta-analyses on therapeutic agents investigated by three or more independent research groups using the same outcome. The DerSimonian-Laird method for random effects was applied with P < 0.05.

RESULTS: Of the 56 different therapeutic agents assessed, 7 met our inclusion criteria for the meta-analysis. The prostacyclin analog iloprost increased the weighted mean of the early bursting pressure of colonic anastomoses in male rats by 60 mmHg (95%CI: 30-89) vs the controls, and the immunosuppressant tacrolimus increased this value by 29 mmHg (95%CI: 4-53) vs the controls. Erythropoietin showed an enhancement of bursting pressure by 45 mmHg (95%CI: 14-76). The anabolic compound growth hormone augmented the anastomotic strength by 21 mmHg (95%CI: 7-35), possibly via the up-regulation of insulin-like growth factor-1, as this growth factor increased the bursting pressure by 61 mmHg (95%CI: 43-79) via increased collagen deposition. Hyperbaric oxygen therapy increased the bursting pressure by 24 mmHg (95%CI: 13-34). Broad-spectrum matrix metalloproteinase inhibitors increased the bursting pressure by 48 mmHg (95%CI: 31-66) on postoperative days 3-4. In the only human study, the AL incidence was not significantly reduced in the 103 colorectal patients treated with aprotinin (11.7%) compared with the 113 placebo-treated patients (9.7%).

CONCLUSION: This systematic review identified only one randomized clinical trial and seven therapeutic agents from pre-clinical models that could be explored further for the prophylaxis of AL after colorectal surgery.

Growth factors and gastrointestinal anastomotic healing

BACKGROUND

Failure of anastomotic healing in the gastrointestinal tract is a major source of surgery-related morbidity, repeated surgical procedures, and impaired quality of life. Growth factors have been shown to be involved in healing processes in various tissues including the gastrointestinal tract. This opens the perspective to use growth factors therapeutically to support impaired anastomotic healing. The aim of the present study was to review the particular role of several growth factors in different phases of anastomotic healing, experimental approaches of growth factor application, and to discuss possibilities and limitations of growth factor-directed interventions in gastrointestinal surgery.

MATERIALS AND METHODS

A PubMed search was performed to examine the potential role of fibroblast growth factor, epidermal growth factor, heparin binding EGF-like growth factor, transforming growth factor β, insulin-like growth factor I, vascular endothelial growth factor, and platelet-derived growth factor during anastomotic healing.

RESULTS

Growth factors show beneficial effects on a broad range of cell types and regulate various processes during all phases of tissue healing. Despite extensive research in the field of growth factors, additional evidence is needed before translating into a clinical setting.

CONCLUSIONS

Future research should focus on adequate sustained but limited drug delivery. Undesired side effects, such as formation of strictures, development of peritoneal adhesions, and potential induction of malignancies, have to be reflected. Although growth factor application is currently far from clinical routine in gastrointestinal surgery, it might find application in selected patients at risk for impaired anastomotic healing, such as patients with long-time steroid therapy, immunosuppressives, inflammatory disorders, sepsis, hemodynamic shock, malnutrition, or neoadjuvant radiochemotherapy.

The effect of glucagon-like Peptide-2 receptor agonists on colonic anastomotic wound healing

Background. Glucagon-like peptide 2 (GLP-2) is an intestinal specific trophic hormone, with therapeutic potential; the effects on intestinal healing are unknown. We used a rat model of colonic healing, under normoxic, and stress (hypoxic) conditions to examine the effect of GLP-2 on intestinal healing. Methods. Following colonic transection and reanastomosis, animals were randomized to one of six groups (n = 8/group): controls, native GLP-2, long-acting GLP-2 (GLP-2- MIMETIBODY, GLP-2-MMB), animals were housed under normoxic or hypoxic (11%  O₂) conditions. Animals were studied five days post-operation for anastomotic strength and wound characteristics. Results. Anastomotic bursting pressure was unchanged by GLP-2 or GLP-2-MMB in normoxic or hypoxic animals; both treatments increased crypt cell proliferation. Wound IL-1β increased with GLP-2; IFNγ with GLP-2 and GLP-2-MMB. IL-10 and TGF-β were decreased; Type I collagen mRNA expression increased in hypoxic animals while Type III collagen was reduced with both GLP-2 agonists. GLP-2 MMB, but not native GLP-2 increased TIMP 1-3 mRNA levels in hypoxia. Conclusions. The effects on CCP, cytokines and wound healing were similar for both GLP-2 agonists under normoxic and hypoxic conditions; anastomotic strength was not affected. This suggests that GLP-2 (or agonists) could be safely used peri-operatively; direct studies will be required.

Insulin-like growth factor 1-coated sutures improve anastomotic healing in an experimental model of colitis

BACKGROUND

: Exogenously applied insulin-like growth factor (rhIGF-1) may improve normal intestinal healing. This study examined the effect of rhIGF-1-coated sutures on anastomotic healing in experimental colitis.

METHODS

: Acute colitis was induced in rats by dextran sodium sulphate (DSS). Inflammation was assessed by clinical Disease Activity Index (DAI), myeloperoxidase (MPO) measurement and histological examination. A distal colonic anastomosis was performed using sutures coated with rhIGF-1 dissolved in poly(D,L-lactide) (PDLLA) under general anaesthetic. Anastomotic healing was evaluated histologically, and by hydroxyproline measurement and bursting parameters after 1, 3 and 7 days, and compared with healthy, DSS and DSS + PDLLA controls.

RESULTS

: DAI, MPO and histological inflammation scores were significantly increased in all animals treated with DSS. Bursting occurred less often within the anastomotic line on day 3 in the IGF group than in DSS controls (three versus eight of ten). On day 7, the IGF group had significantly increased histological healing scores (mean(s.e.m.) 12.5(0.7) versus 9.2(0.8) (P < 0.050)) and hydroxyproline content (4.6(0.3) versus 3.6(0.1) mg/g tissue; P < 0.050) compared with DSS controls.

CONCLUSION

: IGF-1-coated sutures improve important aspects of anastomotic healing in rats with experimental colitis.

Gastric pentadecapeptide BPC 157 and short bowel syndrome in rats

The gastric pentadecapeptide BPC 157, which was shown to be safe as an antiulcer peptide in trials for inflammatory bowel disease (PL14736, Pliva), successfully healed intestinal anastomosis and fistula in rat. Therefore, we studied for 4 weeks rats with escalating short bowel syndrome and progressive weight loss after small bowel resection from fourth ileal artery cranially of ileocecal valve to 5 cm beneath pylorus. BPC 157 (10 microg/kg or 10 ng/kg) was given perorally, in drinking water (12 ml/rat/day) or intraperitoneally (once daily, first application 30 min following surgery, last 24 h before sacrifice). Postoperatively, features of increasingly exhausted presentation were: weight loss appearing immediately regardless of villus height, twofold increase in crypt depth and fourfold increase in muscle thickness within the first week, jejunal and ileal overdilation, and disturbed jejunum/ileum relation. In contrast, constant weight gain above preoperative values was observed immediately with BPC 157 therapy, both perorally and parenterally, and villus height, crypt depth, and muscle thickness [inner (circular) muscular layer] also increased, at 7, 14, 21, and 28 days. Moreover, rats treated with pentadecapeptide BPC 157 showed not different jejunal and ileal diameters, constant jejunum-to-ileum ratio, and increased anastomosis breaking strength. In conclusion, pentadecapeptide BPC 157 could be helpful to cure short bowel syndrome.

Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia) heals ileoileal anastomosis in the rat

PURPOSE

Gastric pentadecapeptide BPC 157 (BPC 157), which has been shown to be safe in clinical trials for inflammatory bowel disease (PL-10, PLD-116, PL14736, Pliva, Croatia), may be able to cure intestinal anastomosis dehiscence. This antiulcer peptide shows no toxicity, is limit test negative, and a lethal dose is not achieved. It is stable in human gastric juice. In comparison with other standard treatments it is more effective for ulcers and various wounds, and can be used without a carrier needed for other peptides, both locally and systemically (i.e., perorally, parenterally). We studied the effectiveness of BPC 157 for ileoileal anastomosis healing in rats.

METHODS

We assessed ileoileal anastomosis dehiscence macroscopically, histologically, and biomechanically (volume [ml] infused through a syringe-perfusion pump system (1 ml/10 s), and pressure [mmHg] to leak induction [catheter connected to a chamber and a monitor, at 10 cm proximal to anastomosis]), at 1, 2, 3, 4, 5, 6, 7, and 14 days. BPC 157 (10 microg, 10 ng, 10 pg/kg i.p. (or saline [5 ml/kg]) was first administered after surgery, while it was last given 24 h before either assessment or sacrifice.

RESULTS

Throughout the experiment, both higher doses of BPC 157 were shown to improve all parameters of anastomotic wound healing. The formation of adhesions remained slight, the blood vessels were filled with blood, and a mild intestinal passage obstruction was only temporarily observed. Anastomosis without leakage induces markedly higher volume and pressure values, with a continuous increase toward healthy values. From day 1, edema was markedly attenuated and the number of granulocytes decreased, while from days 4 or 5 necrosis decreased and granulation tissue, reticulin, and collagen formation substantially increased, thus resulting in increased epithelization.

CONCLUSION

This study showed BPC 157 to have a beneficial effect on ileoileal anastomosis healing in the rat.

Effect of IGF-I on healing of colonic anastomoses in rats under 5-FU treatment

BACKGROUND

The aim of this experimental study was to investigate whether insulin-like growth factor I (IGF-I) can protect the colonic healing from the adverse effects of intraperitoneal administration of 5-fluorouracil (5-FU).

MATERIALS AND METHODS

Eighty male Wistar rats were randomized into four groups of 20 rats each. Immediately after anastomoses were performed, rats in the control group were injected with 1 mL/100 gr of intraperitoneal saline solution, which was repeated daily until killed. Rats in the 5-FU and IGF-I +5-FU groups received 5-FU in a dose of 20 mg/kg body weight intraperitoneally, from the day of operation until killed. Rats in the IGF-I and IGF-I +5-FU groups received IGF-I in a dose of 2 mg/kg body weight intraperitoneally, immediately after the colonic anastomosis was performed and on 2nd, 4th, and 6th postoperative day. Rats were sacrificed on the 7th postoperative day.

RESULTS

The dehiscence rate in the 5-FU group was 30% and it was significantly higher compared with the control and the IGF-I group (P = 0.020 for both comparisons). However, in the IGF-I +5-FU group, the dehiscence rate decreased to 10%. The administration of IGF-I resulted in a significant rise of bursting pressure in the IGF-I +5-FU group compared with the 5-FU group (P < 0.001). There was no statistical difference in bursting pressure between the IGF-I +5-FU and control groups (P = 1.000). The hydroxyproline levels were higher in the IGF-I and the IGF-I +5-FU groups as a result of the stimulating act of IGF-I.

CONCLUSION

IGF-I, when given intraperitoneally, seems to mediate some of the adverse effects of 5-FU on the colonic healing in rats.

Contribution of insulin-like growth factor I to the healing of colonic anastomoses in rats

The aim of this experimental study was to investigate the contribution of insulin-like growth factor I (IGF)-I in the colonic healing process when injected intraperitoneally after colon resection. Forty male Wistar rats were used. Rats in the control group were injected with 3 mL of a solution of 0.9% NaCl intraperitoneally after the operation and on postoperative day 2, 4, and 6. Rats in the IGF-I group received recombinant human IGF-I in a dose of 2 mg/kg body weight intraperitoneally, immediately after the colonic anastomosis was performed and on postoperative day 2, 4, and 6. All rats were killed on postoperative day 7. The hydroxyproline tissue content was significantly higher in the IGF-1 group than in the control group. The bursting pressures were also significantly higher in IGF-1 group than in the control group. The weight change between the groups differed significantly; in the control group the average weight decreased about 5% postoperatively, while in the IGF-1 group the average weight increased about 6%. The average inflammatory cell infiltration score was significantly higher in the control group. Neoagiogenesis did not differ significantly between the two groups. The fibroblast activity differed significantly between the two groups, as the control group had significantly less fibroblasts compared to the IGF-1 group. In conclusion, IGF-I when given intraperitoneally stimulates the healing of colonic anastomoses in the rats. Further studies are required in order to determine whether this effect is dose related.

Early glutamine-enriched enteral feeding facilitates colonic anastomosis healing: light microscopic and immunohistochemical evaluation

Problems related to colonic anastomosis healing constitute the major morbidity in colorectal surgery. Patients without appropriate nutritional support are at higher risk of postsurgical complications, mainly due to reduced wound healing. Therefore, we investigated the effect of early and late postoperative total enteral nutrition (TEN) and glutamine addition on colon anastomosis healing using light microscopy and immunohistochemistry (IGF-I immunolabelling). In this study, 40 Wistar-albino rats underwent distal left colonic transection and anastomosis. The rats were then divided into four groups given different diets: delayed total enteral nutrition (dTEN; beginning 3 days postoperatively), delayed TEN with added glutamine (dTEN+Glutamine), early TEN (eTEN; beginning within 6h postoperatively), and early TEN with added glutamine (eTEN+Glutamine). Colon segments, including the anastomosis, were excised 7 days postoperatively and evaluated histopathologically for inflammation, mucosal healing, submucosal-muscular layer repair, the amounts of necrosis and vascularisation and immunohistochemically for IGF-I labelling. The inflammation and necrosis scores in the dTEN and dTEN+Glutamine groups were significantly greater than in the eTEN and eTEN+Glutamine groups. The IGF-I immunoreactivity increased in the eTEN, eTEN+Glutamine, and dTEN+Glutamine groups compared to dTEN (p<0.05). We concluded that early TEN and glutamine enrichment in the postoperative period improve anastomosis healing via IGF-I.

The effect of insulin-like growth factor I on healing of colonic anastomoses in cortisone-treated rats

PURPOSE

This study was designed to investigate whether intraperitoneally injected insulin-like growth factor I is able to protect colonic healing from the adverse effects of hydrocortisone therapy.

METHODS

Eighty female Wistar rats were randomized into four groups (20 rats each). After resection of a segment of transverse colon, an end-to-end anastomosis was performed. Hydrocortisone (5 mg/kg body weight) was injected intramuscularly in rats of cortisone (Group B) and insulin-like growth factor I + cortisone (Group D) groups once daily for seven days before and after the operation. Insulin-like growth factor I (2 mg/kg body weight) was intraperitoneally injected in rats of the insulin-like growth factor I (Group C) and the insulin-like growth factor I + Cortisone (Group D) groups immediately after operation and on the second, fourth, and sixth postoperative days. Rats were killed on the seventh postoperative day. Anastomoses were graded macroscopically and histologically, and bursting pressures and anastomotic hydroxyproline levels were recorded. Statistical analyses were performed by using Fisher's exact test for the comparison of proportions and ANOVA for the comparison of means among groups with subsequent post-hoc analysis using Bonferroni correction.

RESULTS

Leakage rate was significantly higher in the cortisone (Group B) group. Bursting pressures were significantly lower in the cortisone group, whereas they were significantly higher in the insulin-like growth factor I and insulin-like growth factor I + cortisone groups (Group C and D). Histology revealed a significant decrease of inflammatory cell infiltration, neoangiogenesis, and fibroblast activity in the cortisone group compared with the control group, whereas these parameters were significantly higher in the insulin-like growth factor I and insulin-like growth factor I + cortisone groups. Hydroxyproline levels were significantly higher in the insulin-like growth factor I and insulin-like growth factor I + cortisone groups.

CONCLUSIONS

Hydrocortisone inhibits the healing of colonic anastomoses. However, insulin-like growth factor I given intraperitoneally mediates the deleterious effects of cortisone and protects colonic healing in rats.

Suppressor of cytokine signaling-2 modulates the fibrogenic actions of GH and IGF-I in intestinal mesenchymal cells

Growth hormone (GH) and IGF-I play important roles in wound healing during intestinal injury and inflammation, but there is also indirect evidence that locally expressed IGF-I may act to induce excessive collagen deposition, which can lead to intestinal fibrosis. Factors that dictate the balance between normal wound healing and excessive healing responses are unknown. Using RNase protection assay and in situ hybridization, we determined whether GH and/or IGF-I increase type I collagen deposition in the intestine of rats fed by total parenteral nutrition (TPN), a feeding modality used for many patients following intestinal surgery and resection. We also used an in vitro model system to confirm our in vivo effects and to directly evaluate the relative potency of GH and IGF-I on DNA synthesis and collagen deposition in intestinal myofibroblasts. Both GH and IGF-I stimulated collagen production in vivo and in vitro, and IGF-I, but not GH, stimulated DNA synthesis in vitro. In collagen production, GH was less potent than IGF-I. Suppressors of cytokine signaling (SOC) are cytokine-inducible proteins that negatively feedback to inhibit the actions of cytokines and we recently found that GH selectively upregulates SOC-2 in the intestine of TPN-fed rats. We examined whether SOC-2 may be responsible for the difference in magnitude of action of GH and IGF-I on collagen accumulation. GH, but not IGF-I, induced SOC-2 in isolated myofibroblasts, and overexpression of SOC-2 led to a suppression of GH- and IGF-I-induced collagen accumulation. SOC-2 null mice infused with IGF-I showed greater collagen gene expression compared with wild-type (WT) mice. Myofibroblasts isolated from SOC-2 null mice showed increased IGF-I-stimulated DNA synthesis compared with WT cells. Taken together, these findings suggest that SOC-2 induced by GH may play an important role in suppressing collagen accumulation and mesenchymal cell proliferation induced by GH or GH-induced IGF-I, providing a mechanism for the differing potencies of GH and IGF-I on intestinal mesenchyme and collagen synthesis.

The effect of recombinant human growth hormone (rhGH) on trinitrobenzene sulfonic acid-induced colitis in rats: an experimental study

The limited efficacy of standard medical therapies for inflammatory bowel diseases has resulted in a continuing search for alternative treatments. Growth hormone (GH) has shown to have mutagenic and proliferative effects on intestinal cells. This study was designed to identify the effect of growth hormone on trinitrobenzene slfonic acid-induced colitis (TNBSIC) in rats. This study was carried out on 30 rats, divided in 3 groups: group 1: TNBSIC+ GH, group 2: TNBSIC, group 3: saline enema. Colitis was induced in male Sprague-Dawley rats (200 g-250 g) by intracolonic installation of 2, 4, 6-trinitrobenzene sulphonic acid in 50% ethanol. GH treatment has been started and continued throughout the study after inducing colitis. All rats were killed after 5 weeks and colonic segments were examined histopathologically. Microscopic and macroscopic damage scores were caulculated. Intestinal damage scores were found higher in Goups II when compared with treatment group (P < 0.05). There was no damage in group 3 as expected. Both macroscopic and microscopic scores were highest in group 2 (P < 0.05). The myloperoxidase activity was found lower comparing to group 2 (P < 0.05). In conclusion, growth hormone replacement had protective effects against colonic inflammation while reducing intestinal damage on TNB-induced colitis.

Effects of recombinant human growth hormone and nandrolone phenylpropionate on the healing of ischemic colon anastomosis in rats

PURPOSE

Recombinant human growth hormone and nandrolone phenylpropionate are two different anabolic agents. This study was designed to investigate the effects of these anabolic agents on the healing of ischemic colon anastomosis in rats.

METHODS

Seventy adult male Wistar rats were divided into five groups (n = 14). Group I was the sham laparotomy group. In the other groups, surgical procedures consisting of transsection and anastomosis were made at a distance 3 cm from the peritoneal reflection. Group II was the nonischemic control group. Ischemic colon model was produced in the remaining groups. Group III was the untreated control group. Groups IV and V received recombinant human growth hormone and nandrolone phenylpropionate, respectively. Bursting pressure and hydroxyproline levels were measured on the third and seventh postoperative days to evaluate anastomotic healing.

RESULTS

Recombinant human growth hormone increased both collagen deposition and bursting pressure significantly at postoperative Days 3 and 7 compared with the sham and untreated control groups (P < 0.005). When compared with the untreated control, nandrolone phenylpropionate significantly increased collagen deposition at postoperative Days 3 and 7 (P < 0.005) and bursting pressure only at postoperative Day 3 (P < 0.005).

CONCLUSIONS

Recombinant human growth hormone has more favorable therapeutic effects on the healing of ischemic colonic anastomoses than nandrolone phenylpropionate. Recombinant human growth hormone also improves healing of nonischemic colonic anastomosis.

Repair of full-thickness bowel injury

OBJECTIVE

Colon surgery is more and more often performed in complex situations such as after trauma, under immunosuppression, or in the elderly. Even under optimal conditions, anastomosis fails in certain situations. The objective of this study was to demonstrate the normal phases of bowel healing and to review the local and systemic factors affecting healing with special attention to critical care variables such as major surgery, acute hemorrhage, and infections.

DATA SOURCE

MEDLINE cited and/or published articles.

DESIGN

Review analysis.

RESULTS

Colon healing is a structured cascade of different phases that can be affected by a multitude of local (infection, ischemia) and systemic (diabetes, malnutrition, anemia, hypothermia, trauma) factors. The normal phases of repair, the resulting bursting pressure as an experimental index of healing, and the available published data on local and systemic factors affecting healing are summarized.

CONCLUSION

Several local and systemic factors negatively affect bowel healing; there is still a small portion of patients who fail to heal, suggesting that intrinsic factors need to be analyzed.

Insulin-like growth factor I and truncated keratinocyte growth factor accelerate healing of left-sided colonic anastomoses

BACKGROUND

Human full-length keratinocyte growth factor (KGF) promotes healing of colon anastomoses in rats through mechanisms other than enhancement of collagen synthesis. Since insulin-like growth factor (IGF) I increases matrix synthesis, the aim of this study was to evaluate the effect of systemic truncated KGF (tKGF), IGF-I and combined tKGF-IGF-I administration on the healing of colonic anastomoses in rats.

METHODS

Rats underwent laparotomy, division of the left colon, and sigmoidosigmoidostomy. tKGF (1 mg/kg), IGF-I (1 mg/kg), tKGF-IGF-I (both 1 mg/kg) or vehicle was administered intraperitoneally in four groups (n = 18 per group) 12 h before surgical intervention, and then once daily until killing (six animals per group; 2, 4 and 6 days after surgery). Bursting pressure measurements, histological evaluation, morphometric analysis, mucin and collagen staining, and 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry of the anastomotic site were undertaken.

RESULTS

Administration of tKGF, IGF-I and the combination of both growth factors significantly increased anastomotic bursting pressure at postoperative day 2 (63, 71 and 113 per cent respectively), day 4 (68, 83 and 80 per cent) and day 6 (48, 43 and 43 per cent) compared with the control group. No intergroup differences were found. Histological examination, mucin and BrdU staining, and measurement of colonic crypt depth indicated less inflammation, increased acidic mucin content, a higher crypt cell proliferation rate and thickened mucosal layer in the growth factor-treated animals than in controls. Enhanced collagen staining was observed only in IGF-treated animals.

CONCLUSION

tKGF and IGF-I markedly accelerate the healing of colonic anastomoses in rats. However, combined administration of the two growth factors does not show additional benefit. Both growth factors may be acting to accelerate host reparative processes as well as to enhance protection of the anastomotic wound bed.