Effect of growth hormone, hyperbaric oxygen and combined therapy on the gastric serosa

Abstract

Aim: To investigate the role of growth hormone (GH), hyperbaric oxygen therapy (HBOT) and combined therapy on the intestinal neomucosa formation of the gastric serosa.

Methods: Forty-eight male Wistar-albino rats, weighing 250-280 g, were used in this study. The rats were divided into four groups (n = 12): Group 1, control, gastric serosal patch; Group 2, gastric serosal patch + GH; Group 3, gastric serosal patch + HBOT; and Group 4, gastric serosal patch + GH + HBOT. Abdominal access was achieved through a midline incision, and after the 1-cm-long defect was created in the jejunum, a 1 cm × 1 cm patch of the gastric corpus was anastomosed to the jejunal defect. Venous blood samples were taken to determine the insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) basal levels. HBOT was performed in Groups 3 and 4. In Groups 2 and 4, human GH was given subcutaneously at a dose of 2 mg per kg/d for 28 d, beginning on the operation day. All animals were sacrificed 60 d after surgery. The jejunal segment and the gastric anastomotic area were excised for histological examination. The inflammatory process, granulation, collagen deposition and fibroblast activity at the neomucosa formation were studied and scored. Additionally, the villus density, villus height, and crypt depth were counted and recorded. The measurements of villus height and crypt depth were calculated with an ocular micrometer. New vessel growth was determined by calculatingeach new vessel in a 1 mm(2) area.

Results: In the histological comparison of groups, no significant differences were observed between the control group and Groups 2 and 3 with respect to epithelialization, granulation, fibroblastic activity and the inflammatory process, but significant differences were present between the control group and all others groups (Groups 2-4) with respect to angiogenesis (P < 0.01) and collagen deposition (P < 0.05, P < 0.01). Significant differences between the control group and Group 4 were also observed with respect to epithelialization and fibroblastic activity (P < 0.01 and P < 0.05, respectively). There were significant differences in villus density in all of groups compared with the control group (P < 0.05). Crypt depth was significantly greater in Group 4 than in the control group (P < 0.05), but no other groups had deeper crypts. However, villus height was significantly longer in Groups 2 and 4 than in the control group (P < 0.05). The comparison of groups revealed, significant difference between control group and Groups 2 and 4) with respect to the levels of IGF-1 and IGFBP-3 (P < 0.01) 3 wk after the operation.

Conclusion: HBOT or GH and combined therapy augmented on neomucosal formation. The use of combined therapy produced a synergistic effect on the histological, morphological and functional parameters.

Keywords: Growth hormone; Hyperbaric oxygen; Hypoxia; Neomucosa; Short bowel syndrome.

Figure 1

Surgical procedure and histopathological assessment. A, B: Anastomotic line is shown between the gastric surface and jejunum, C: Outer surface of the neomucosa formation is shown with the jejunal segment; D: Inner surface of the neomucosa is shown, and the neomucosa has a typical small intestinal phenotype.

Figure 2

Histological and morphologic evaluation. A: Unexpected neomucosal formation. The gastric corpus mucosa can be seen. The squamous epithelium and lamellar keratinization formed from the anastomosis [Hematoxylin and eosin (HE) × 100] (Group 3); B: Granulation tissue and newly formed neomucosa. The blue area is connective tissue (Masson Trichrome × 100) (Group 4); C: In the gastric mucosa of the large granulation tissue, newly formed goblet cells can be seen (HE × 100) (Group 4); D: The left side shows the gastric mucosa, and the right side shows newly formed neomucosa that contains mucin. The granulation tissue is reduced (HE × 100) (Group 4).

Figure 3

There were significant differences in the villus density in all of the groups compared with the control group. A: Gastric corpus mucosa on the left, newly formed thin neomucosa on the right. The muscularispropria has not yet formed. The granulation tissue regressed [Hematoxylin and eosin (HE) × 100] (Group 3); B: Neomucosa formation is observed at the bottom of the gastric mucosa (HE × 125) (Group 4); C: The granulation tissue is in the middle, with newly formed neomucosa on either side. At the bottom, the stomach tissue is visible (HE x 100) (Group 2); D: The early development of the mucosal layer and granulation tissue (HE x 125) (Group 1).