Catecholamine levels in relation to number of spermatozoa inseminated "in vitro" in the human being.

We tried to understand and to explain why such a high number of sperm cells is necessary for human in vitro fertilization in relation to the possible role of catecholamines. Sperm cells, even washed several times, bring catecholamines (epinephrine, nor-epinephrine and dopamine). When incubated in a suitable medium, with Taurine and reducing agents, the catecholamine level remains constant for 5 hours. The origin of these amines and the positive vs negative effect of "in vitro" insemination with a high number of spermatozoa are discussed.