Final answer:
Endothelins are a family of peptides released by the endothelium that are powerful vasoconstrictors. They constrict blood vessels and increase blood pressure.
Step-by-step explanation:
Endothelins, a family of peptides, are released by the endothelium and are among the most potent vasoconstrictors known. They are 21-amino acid peptides produced by endothelial cells of the renal blood vessels, mesangial cells, and cells of the DCT. Hormones such as angiotensin II, bradykinin, and epinephrine stimulate the release of endothelins. They work by causing the constriction of blood vessels, which increases blood pressure.