The urethral or periurethral glands (also Littre glands after Alexis Littré)[1] are glands that branch off the wall of the urethra of male mammals. The glands secrete mucus[2] and are most numerous in the section of the urethra that runs through the penis. Urethral glands produce a colloid secretion containing glycosaminoglycans; this secretion protects the epithelium against urine.[3]