Expression of the platelet-activating factor receptor in human spermatozoa: differences in messenger ribonucleic acid content and protein distribution between normal and abnormal spermatozoa

Objective: To determine the expression and distribution of the platelet-activating factor (PAF) receptor in normal and abnormal specimens of human spermatozoa. Design: Prospective analysis of membrane-bound PAF receptors by immunofluorescence and PAF receptor messenger RNA by quantitated reverse transcription–polymerase chain reaction in normal and abnormal spermatozoa. Setting: University-based reproductive genetics laboratory. Patient(s): Men undergoing routine semen analysis. Intervention(s): Normal and abnormal spermatozoa were exposed to rabbit anti–PAF receptor antibody, fluorescein isothiocyanate–conjugated goat anti-rabbit antibody, and fluorescent microscopy or subjected to RNA isolation by acid-phenol extraction and quantitated (MIMIC Construction Kit [Clontech Laboratories, Inc., Palo Alto, CA]) reverse transcription–polymerase chain reaction. Main Outcome Measure(s): Fluorescent intensities at six locations along spermatozoa (end piece, principal tail, midpiece, neck, proximal head, and acrosomal region) and PAF receptor expression (messenger RNA) levels. Result(s): Immunofluorescence demonstrated a significant difference in PAF receptor distribution between normal and abnormal human spermatozoa, specifically at the neck region. Additionally, abnormal spermatozoa were found to have statistically significantly more PAF receptor messenger RNA than normal spermatozoa. Conclusion(s): Platelet-activating factor receptor expression and distribution are significantly altered in abnormal spermatozoa and this may be the result of some defect in gene transcription.