Doses of levonorgestrel comparable to that delivered by the levonorgestrel-releasing intrauterine system can modify the in vitro expression of zona binding sites of human spermatozoa

• Published in: Contraception (Stoneham) 2006, Vol.73 (1), p.97-101
• Main Authors: José Munuce, María, Nascimento, Josiane A.A., Rosano, Germán, Faundes, Anibal, Bahamondes, Luis
• Format: Article
• Language: English
• Subjects: Acrosome reaction; Acrosome Reaction - drug effects; Biological and medical sciences; Contraceptive Agents, Female - administration & dosage; D-Mannose binding site; Dose-Response Relationship, Drug; Female; Fluorescein-5-isothiocyanate - analogs & derivatives; Fluorescent Dyes; Genital system. Reproduction; Gynecology. Andrology. Obstetrics; Human spermatozoa; Humans; Lectins, C-Type - analysis; Lectins, C-Type - drug effects; Levonorgestrel; Levonorgestrel - administration & dosage; Levonorgestrel-releasing intrauterine system; Male; Mannose - metabolism; Mannose-Binding Lectins - analysis; Mannose-Binding Lectins - drug effects; Medical sciences; Pharmacology. Drug treatments; Receptors, Cell Surface - analysis; Receptors, Cell Surface - drug effects; Serum Albumin, Bovine; Sperm Capacitation; Spermatozoa - chemistry; Spermatozoa - drug effects; Spermatozoa - metabolism; Uterus - drug effects; Zona Pellucida - metabolism
• ISSN: 0010-7824; 1879-0518
• DOI: 10.1016/j.contraception.2005.06.072

The levonorgestrel-releasing intrauterine system (LNG-IUS) exerts its contraceptive effect by interfering with sperm transport through the female genital tract and with ovulation. However, the possibility cannot be discarded that the device exerts a direct effect on sperm function, thus, helping prevent fertilization. The purpose of this study is to evaluate whether LNG at doses comparable to that measured in the uterus during the use of the LNG-IUS affects the detection of D-mannose binding sites or zona pellucida (ZP) receptors on human spermatozoa. The association with acrosomal status was also investigated. Seventeen semen samples from fertile men were used, and spermatozoa were separated using a Percoll gradient and incubated for 22 h at 37°C under 5% CO 2 in air. Capacitated spermatozoa were exposed for 30 min to 1000 or 10,000 ng/mL of LNG or control medium. D-Mannose binding sites were detected using commercial D-mannosylated bovine serum albumin conjugated with fluorescein isothiocyanate, and the percentage of specific patterns (II and III) was recorded. The acrosome reaction was evaluated using the Pisum sativum technique. Levonorgestrel releasing significantly increased (p