Pulmonary passage of canine adipose tissue-derived mesenchymal stem cells through intravenous transplantation in mouse model

Importance: The intravenous administration of adipose tissue -derived mesenchymal stem cells (AdMSCs) in veterinary medicine is an attractive treatment option. On the other hand, it can result in severe complications, including pulmonary thromboembolism (PTE). Objective: The present study assessed the occurrence of PTE after the intravenous infusion of canine AdMSCs (cAdMSCs) into experimental animals. Methods: Five -week-old male BALB/c hairless mice were categorized into groups labeled A to G. In the control group (A), fluorescently stained 2 x 10 6 cAdMSCs were diluted in 200 mu L of suspension and injected into the tail vein as a single bolus. The remaining groups included the following: group B with 5 x 10 6 cells, group C with 3 x 10 6 cells, group D with 1 x 10 6 cells, group E with 1 x 10 6 cells injected twice with a one -day interval, group F with 2 x 10 6 cells in 100 mu L of suspension, and group G with 2 x 10 6 cells in 300 mu L of suspension. Results: Group D achieved a 100% survival rate, while none of the subjects in groups B and C survived ( p = 0.002). Blood tests revealed a tendency for the D-dimer levels to increase as the cell dose increased ( p = 0.006). The platelet count was higher in the low cell concentration groups and lower in the high cell concentration groups ( p = 0.028). A histological examination revealed PTE in most deceased subjects (96.30%). Conclusions and Relevance: PTE was verified, and various variables were identified as potential contributing factors, including the cell dose, injection frequency, and suspension volume.