Primo Vessel Stressed by Lipopolysaccharide in Rabbits

For tracking the primo vascular system, we observed the primo vessels in vivo in situ using the lipopolysaccharide (LPS) response in the lymphatic vessels of a rabbit. Injection of LPS (200 μg/kg) into the lymph nodes resulted in greatly stained primo vessels, which were swollen in some cases. We were able to obtain comparative images through alcian blue and diaminobenzidine staining, which clearly showed different morphologies of the primo vessels. The mechanism causing the response of the primo vessels to the injected LPS is still unclear; however, these results might be a first attempt at giving an explanation of the function of the primo vascular system and identifying the changes in the structure and function of the primo vascular system in response to an external stimulus such as an injection of LPS.