This paper reports a case of super pregnancy in a BALB/c mouse pregnant with 30 pups following induction of superovulation using a PMSG-hCG protocol. Superovulation was induced in 10 mice by injecting 5 IU PMSG followed by 5 IU hCG 48 hours later. Immediately after injection of hCG, animals were placed with males at a ratio of 1 to 1 for 24 hours. On day 14 after mating, animals were killed by cervical dislocation and the uterus was examined for pregnancy and the number of fetuses. The mean (±SEM) number of fetuses observed in ten mice was 5.4±3.18 with an unexpectedly super pregnant mouse bearing 30 fetuses on day 14 of pregnancy.
Animals ; Dislocations ; Fetus ; Humans ; Male ; Mice* ; Pregnancy* ; Superovulation ; Uterus

The following experiments were designed to examine the effect of serum of spayed dogs on superovulation response in mice and rats. In Experiment 1, female mice at diestrus (n=30) were divided into three equal groups and superovulated with either administration of 5 IU pregnant mare serum gonadotropin (PMSG) or recombinant follicle stimulating hormone (rFSH) (reducing dose from 2.5 to 0.5 IU) and 5 IU human chorionic gonadotropin (hCG) administered 48h later. Serum of spayed dogs was administered intraperitoneally at a reduced dose from 0.1 to 0.025 mL in a 48 h period. In Experiment 2, female rats (n=30) at diestrus stage were divided into three equal groups. Superovulation was induced using either 30 IU PMSG, or a dose reduced from 5 to 1 IU rFSH and 25 IU hCG administered 48h later. Serum of spayed dogs was administered in a reduced dose from 0.6 to 0.1 mL in a 48 hour period. Female mice and rats were mated 24 h following hCG administration. On day 14 after mating, animals were euthanized and ovarian sections were fixed for histopathological evaluation and corpus luteum (CL) counting. No significant difference observed in mean (±SEM) number of CLs between the PMSG group and the mice that received serum of spayed dog (10.4±1.3 vs 9.2±1.0). Mean (±SEM) number of CLs tended to be lower in rats that received serum of spayed dog than those of rats which received either PMSG or rFSH (15.1±1.9 vs 23.6±3.1 and 23.1±2.9, P=0.06, respectively). In conclusion, serum of spayed dogs is able to induce a superovulatory response in mice and rats.
Animals ; Chorionic Gonadotropin ; Corpus Luteum ; Diestrus ; Dogs* ; Female* ; Follicle Stimulating Hormone ; Gonadotropins ; Humans ; Mice* ; Rats* ; Superovulation*