A methoxyindole; synthesized in rat pineal gland, retina, and harderian gland; following conversion to a peroxyl radical by HRP, increases the rate of formation of TBARS in liposomes and is cytotoxic to V79 hamster cells; prolongs the estrous cycle and increases diestrous smears, uterine weight, the number of uterine follicles, and plasma levels of 17β-estradiol in female rats