The urethra has epithelial cells, not endothelial cells. Epithelial cells line the lumenal surface of the gastrointestinal tract, as well as the kidney tubules and urinary tract, gall bladder etc. Endothelial cells are often described as specialized epithelia, but the line the entire lumenal surface of the cardiovascular system, I.e. all blood vessels and the heart. The two cells share some similarities, but essentially are completely different.

thanks for your answer David, i will research more.

The urethra surface consist of transitional epithelium cells which lined of proximal 2/3rds and  other 1/3rd - squamous epithelium cells. Epithelium cells, that line of cavities internal surfaces and vessels play a different role and have a different structure principally

Dear Larysa thanks for your answer, is very helpful.

Julio