Histological Study on the Possible Role of Bone Marrow Derived Mesenchymal Stem Cells Therapy in Experimentally Induced Acute Pancreatitis in Albino Rats

Abstract

Acute pancreatitis is a serious inflammatory disease associated with auto-digestion of the gland. This work was aimed to study the role of BM-MSCs as a therapeutic modality in acute pancreatitis induced by L-arginine in rats. It was also aimed to compare the efficacy of early versus late injection of BM-MSCs in restoration of normal exocrine pancreatic parenchyma. Sixty five adult male albino rats weighing 200-250 gm were used in this study. In addition 10 male albino rats weighing 80-100 gm and aging 3-6 weeks were used for preparation of BM-MSCs. The experimental animals were classified into three groups: Group I (control group): this group consisted of fifteen animals. It was further subdivided into three subgroups, 5 rats each: Subgroup ІA: It included 5 male albino rats that were sacrificed after 24 hours from injection of equivalent dose of saline. Subgroup ІB: It included 5 male albino rats that were sacrificed after 72 hours from injection of equivalent dose of saline. Subgroup ІC: It included 5 male albino rats that were sacrificed after 2 weeks from injection of equivalent dose of saline. Group ІІ: L-arginine induced pancreatitis group: It included 30 male albino rats in which acute pancreatitis was induced. It was further subdivided into three subgroups, 10 rats each. Subgroup ІІA: It consisted of 10 rats which were allowed to live for 24 hours after the last injection of L-arginine. Subgroup ІІB: It included 10 rats which were allowed to live for 72 hours after the last injection of L-arginine Subgroup ІІC: It included 10 rats which were left for 2weeks after the last injection of L-arginine for spontaneous healing of pancreatitis. Group ІІІ: Stem cells treated group: It included 20 male albino rats in which acute pancreatitis was induced followed by injection of cultured and labeled BM-MSCs in phosphate buffer saline in rat tail vein. It was further subdivided into two subgroups, 10 rats each. Subgroup ІІІA: It consisted of 10 rats which were injected with bone marrow derived mesenchymal stem cells 24 hours after the last injection of L-arginine. They were allowed to live for two weeks. Subgroup ІІІB: It included 10 rats which were injected with bone marrow derived mesenchymal stem cells 72 hours after the last injection of L-arginine. They were allowed to live for two weeks. One rat from each of subgroups IIIA and IIIB was sacrificed after one week to ensure homing of BM-MSCs into rat pancreas. Blood sample were collected for laboratory serum amylase then pancreatic specimens were obtained, fixed and processed for histological study. Other small pieces of pancreatic tissues (1mm³) were freshly cut and fixed immediately in buffered formol glutaraldehyde (pH 7.3). Semithin sections were prepared and stained with toluidine blue.