Effects of a new indole derivative on guinea pig reproduction

The effect of a new indole derivative, (1,1,3-trimethyl-3-(3'-indolyl)-1,2,3,4-tetra-hydrocyclopent[b]-in dole) denoted 1 related to indomethacin and yeuhchukene 2 were tested on guinea pig reproduction. In mating experiments ten females were given compound 1 p.o. from cycle day 14 and onwards throughout pregnancy. Two groups of ten females each were used as controls. Conception occurred significantly (p less than 0.001) faster in the treatment group. The litter size was significantly (p less than 0.001) smaller after treatment with the indole derivative. Dams and pups did not seem to have been adversely affected by the treatment as judged by their exterior, behavior and survival. The results are suggested to be due to a reduction in the number of ova available for conception (litter size) in combination with improved conditions for ovum implantation and/or a facilitated sperm migration in the female genital tract. These effects are discussed in relation to known effects of arachidonic acid metabolites on reproduction.