Notes: 15(S)-15-methyl Prostaglandin E1 (15(S)-15-methyl PGE1) is a metabolically stable synthetic analog of PGE1 (Item No. 13010). In sharp contrast to the bronchodilatory effects of PGE1, 15(S)-15-methyl PGE1 is a weak constrictor of human respiratory tract smooth muscle.{2218}