Long-term culture of capillary endothelial cells.

TLDR

Capillary endothelial cells from rats, calves, and humans can be cultured long‑term, and unlike aortic endothelial cells, they require conditioned medium for growth. The study aims to develop a method for producing pure capillary endothelial cells to facilitate research on tumor angiogenesis, metastasis, and other pathological roles of capillary endothelium. The authors achieved long‑term culture by employing tumor‑conditioned medium, gelatin‑coated plates, and a primary culture enrichment strategy. Bovine capillary endothelial cells were successfully cloned and maintained for over eight months, producing Factor VIII antigen and angiotensin‑converting enzyme but lacking Weibel‑Palade bodies, whereas human cells contain these organelles; bovine cells grow slowly and die in regular medium but proliferate rapidly and indefinitely in tumor‑conditioned medium, unlike bovine aortic endothelial cells which grow similarly in both media.

Abstract

Capillary endothelial cells from rats, calves, and humans, have been carried in long-term culture. Bovine capillary endothelial cells have been cloned and maintained by serial passage for longer than 8 months. This prolonged culture was accomplished by using tumor-conditioned medium, gelatin-coated plates, and a method of enriching cells in primary culture. Cultured bovine capillary endothelial cells produce Factor VIII antigen and angiotensin-converting enzyme, but do not have Weibel-Palade bodies. Human cells do contain Weibel-Palade bodies. Capillary endothelial cells are distinguished from aortic endothelial cells by their requirement for conditioned medium. Bovine capillary endothelial cells in regular medium grow slowly with a mean doubling time of 67 hr and eventually die. In tumor-conditioned medium, these cells grow rapidly with a doubling time of 28 hr and continue to proliferate for as long as the tumor-conditioned medium is present. In contrast, bovine aortic endothelial cells grow as rapidly in regular medium as in tumor-conditioned medium. This method allows the production of pure capillary endothelial cells that may prove useful for studies of tumor angiogenesis, metastatic mechanisms, and the role of capillary endothelium in other pathologic states.