BOURGEONAL OLFACTORY TRHESHOLD AND HUMAN CAPACITY OF REPRODUCTION: A PROSPECTIVE STUDY

Introduction. The reproductive success requires the release of millions of spermatozoa and eggs and is made more efficient by attractans that guide sperm to the eggs. For mammals the number of eggs is quite small. The question of what determines which one of the many candidate spermatozoa will fertilize the egg remains still without answer. Recent investigations have focused on the sperm Bourgeonal receptor which seems to be involved in the human sperm chemotaxis and seems to be a critical component in the fertilization process1. Human olfactory sensitivity to the sperm attractant odorant Burgeonal is still debated2. Aims: The present prospective case control study has the purpose to investigate the olfactory sensitivity to Butanol and Burgeonal comparing a group of patients not able to have children despite no alteration of the sperm and a normal fertility of the mate against a control group. Methods. The present prospective study investigated a group of 7 aldult males (mean age of 40±3,8) not able to have children in the last 5 years despite no alteration of the sperm and a normal fertility of the mate against a control group of 15 adult males (mean age of 27,5±4,8) without sperm alterations and history of fertility problems. The spermatozoa number and vitality were evaluated; the effect of buorgeonal on sperm chemotaxis, the odor threshold both for butanol and for bourgeonal were compared between the two groups. Preliminary results. The mean total number of spermatozoa did non differ in the two groups (p=0,105), as well as the sperm motility and vitality (p=0,832 and p=0,595, respectively). In both groups, spermatozoa clearly migrated towards bourgeonal (p=0,004 in the control group and p=0,001 in the study group). Nevertheless olfactory threshold for Butanol did not differ between the two groups (p=0,089), the mean olfactory threshold for Burgeonal was 12,6 in the control group and 10,2 in the study group (p=0,01). Conclusions. If confirmed by an invastigation based on a larger series, odor threshold for burgeonal could be of great value in studying the male capacity of reproduction. References 1Spehr M, Gisselmann G, Poplawski A, Riffel JA, Wetzel CH, Zimmer RK, Hatt H. Identification of a testicular odorant receptor mediating human sperm chemotaxis. Science 2003;299:2054-2058. 2Olsson P, Laska M. Human Male Superiority in Olfactory Sensitivity to the Sperm Attractant Odorant Bourgeonal. Chem. Senses 2010;35:427-432