Objective   Semaphorin 4D (Sema4D) acts as a regulator for axon guidance in central nervous system development.However, new evidence indicates that Sema4D has a previously unrecognized function, namely, compensatory angiogenic factor. Thisstudy aimed to investigate the effect of Sema4D on tumor growth and vascularity of colorectal carcinoma (CRC) in nude mice.

  Methods   A total of 70 adult male rats weighing about 200 g were selected and divided into seven groups. These groups were as follows: 1) normal control group (N): rats were injected with 1 ml of normal saline per day; 2) single medicine treatment group (D): rats were administered with 1 ml of Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection per day; 3) single irradiation group (Z): rats were exposed to 20 Gy single whole-chest irradiation and injected with 1 ml of normal saline per day; 4) irradiation with 10 Gy and medicine treatment group (Z10): rats were exposed to 10 Gy single whole-chest irradiation and administered with 1 ml of Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection per day; 5) irradiation with 15 Gy and medicine treatment group (Z15): rats were exposed to 15 Gy single whole-chest irradiation and administered with 1 ml of Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection per day; 6) irradiation with 20 Gy and medicine treatment group (Z20a): rats were exposed to 20 Gy single whole-chest irradiation for four weeks, and administered with 1 ml of Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection per day; and 7) irradiation with 20 Gy and medicine treatment group (Z20b): rats were exposed to 20 Gy single whole-chest irradiation and administered with 1 ml of Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection per day. Two rats were selected and sacrificed at the end of two, four, six, eight, and ten weeks of irradiation. Samples of blood and lung tissues in rats were obtained.

  Results   In the group with single irradiation, the tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) levels in plasma of rats were higher than those in the other groups. In the group with irradiation and medicine treatment, the TNF-α and TGF-β levels in plasma were higher than those in the normal control group and single medicine treatment group. In the group with single irradiation for four weeks some petechial hemorrhages on the surface of the lung were visible to the naked eye. In the groups with medicine treatment, the petechial hemorrhages on the surface of the lung visibly reduced. According to the pathological mechanism of lung tissues, the groups with Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection exhibited less inflammation than the single irradiation group. Irradiation at 20 Gy for four weeks followed by a daily abdominal injection was slightly better than single irradiation, but the effects were not obvious.

  Conclusion   Salviae Miltiorrhizae Liguspyragine Hydrochloride and Glucose Injection could prevent the occurrence of lung injury by reducing the TNF-α and TGF-β levels in plasma. After the occurrence of radiation-induced pneumonitis, the application of medicine could not decrease the symptoms.