Relationship between corpora lutea or fetal number and plasma concentrations of progesterone and testosterone in mice

E. M. Humphreys, R. Ghione, R. G. Gosden, B. M. Hobson, L. Wide
1985 Reproduction  
Blastocysts (1\p=n-\14) were transferred unilaterally into 63 pseudopregnant mice which were killed on Day 17. Plasma progesterone concentrations were significantly (P < 0\m=.\05) lower in animals with one fetus than in those with 2\p=n-\5or 9\p=n-\14fetuses. Plasma testosterone concentrations were correlated with fetal number in mice with 1\p=n-\13fetuses (P < 0\m=.\001). The total placental content of chorionic gonadotrophin in 13 litters varied directly with the number in the litter
more » ... the litter (1\p=n-\6), and was 1\m=.\67\ m=+-\ 0\m=.\15ng/ placenta. The number of corpora lutea per mouse was negatively correlated with mean CL volume per mouse (P < 0\m=.\001), and the number of conceptuses was positively correlated with mean CL volume per mouse (P < 0\m=.\001). The effect of conceptuses on the ovary was systemic. The relationship between plasma testosterone concentration and conceptus number may be due to gonadotrophins acting on the ovary, or androgens produced by the placenta or fetus.
doi:10.1530/jrf.0.0750007 pmid:4032378 fatcat:s6zd4frpwbhwda6efrqoyn54sy