Effect of Pelvic Endometrial Implants on Overall Reproductive Functions of Female Rats

Abstract

The effects of pelvic endometrial implants on the overall reproductive potential of female rats were investigated. After homologous transplantation in the peritoneum, the ectopic endometrium developed into highly vascularized nodes that gradually increased in mass until the 9th week postsurgery and then plateaued. In the presence of these implants, overall reproductive function was adversely affected. The effect was of greatest magnitude during 50-70 days posttransplantation. As compared with values in corresponding controls, ovulation was reduced by 43% (6 of 14) (p < 0.05), mating rate was reduced by 44% (12 of 27) (p < 0.025), and premature termination of pregnancy occurred in 34% (5 of 15) of rats. Wastage of pregnancy, which included complete termination or reduction of fetal number, occurred during the postimplantation course of gestation. Furthermore, 100% of the rats with transplants failed to respond to the copulomimetic stimulation for the induction of pseudopregnancy (p < 0.01, compared with corresponding controls). However, on exposure to vasectomized males, 46% (6 of 13) of these rats exhibited development of pseudopregnancy (p < 0.05, compared with corresponding group receiving copulomimetic stimulation). Increased rate of mating failure and differential pseudopregnancy rates after copulomimetic and natural cervical stimulation suggest that the rats with endometrial explants possibly had an absence or a short appearance of behavioral estrus. Hormonal assessment during the preovulatory phase showed a tendency toward lower mean levels of preovulatory estradiol and significantly lower LH (p < 0.01) and progesterone (p < 0.01) concentrations. The adversely affected reproductive functions may be a secondary consequence of these altered endocrine milieus.

Cellular and molecular basis for endometriosis-associated infertility

“…Rats with endometriosis have also been shown to experience more spontaneous abortions and to have a decreased litter size (Pal et al 1999), an increased incidence of LUFS (Moon et al 1993) and increased early embryonic mortality when compared with sham-operated controls (Stilley et al 2009). This similarity to subfertility seen in human endometriosis makes the rat model a suitable alternative for studying the effects of endometriosis.…”

Reduced Fecundity in Female Rats with Surgically Induced Endometriosis and in Their Daughters: A Potential Role for Tissue Inhibitors of Metalloproteinase 11

“…Beyond the mere growth of endometrial implants in ectopic locations, rats with surgically-induced endometriosis (Endo) display pathophysiologies similar to those of primates and humans with the disease, including pain and infertility [26-28]. An association between the presence of ectopic endometriotic implants in rats and reduced fecundity has been described [27, 29, 30]. However, the causative mechanisms for these phenomena were not investigated.…”

Proteasomes and Proteasome Activator 200 kDa (PA200) Accumulate on Chromatin in Response to Ionizing Radiation

“…Rats with surgically induced endometriosis (Endo) display pathophysiologies similar to those of primates and humans with the disease, including pain and infertility [12][13][14]. An association between the presence of ectopic endometriotic implants and reduced fecundity in rats has been described [13,[15][16][17].…”