Abstract Progesterone plays an important role in the reproductive function and follicular development in mammals. The aim of the present study was to examine the localization of progesterone receptor alpha (PRA) in ovary of pseudopregnant rabbit by immunohistochemical methods. Samples were collected from 14 h. to 18 days of pseudopregnancy. At the first stage of pseudopregnancy (14 h.), the rabbit ovary showed moderate immunostaining of PRA in the granulosa cells and theca interna cells of preovulatory follicle and in the stroma cells. At the middle stage of pseudopregnancy (3-7 days), the rabbit ovary showed strong immunostaining of PRA in ovarian surface epithelial cells, follicular cells of the primary follicle, granulosa cells and theca interna cells of the growing and antral follicles. Moderate immunoexpression of PRA were observed in the large lutein cells and endothelial cells of the corpus haemorrhagicum and corpus luteum and in the stroma cells. At the end of pseudopregnancy (18 days) strong PRA reactions were detected in the small lutein cells of the regressed corpus luteum. Moderate to strong PRA immuno-expression were observed in the proliferated theca interna cells of the atretic antral follicles. The atretic large lutein cells of the regressed corpus luteum showed negative immunostaining for PRA. This study showed that the PRA positive small lutein cells of the regressed corpus luteum and the PRA positive proliferated theca interna cells of the atretic antral follicles were transformed into PRA positive interstitial gland cells. In conclusion, the present study had described the distribution of PRA in the ovary of pseudopregnant rabbit, which is not discussed before in the available literature. It also gives more information about follicular dynamic, formation and origin of interstitial glands, mechanism of ovulation, formation and regression of the corpus luteum.

SUMMARY: Catha edulis Forsk leaves (Khat) is a flowering plant. A high proportion of the adult population in the Arabian Peninsula and the Horn of Africa chews it for its mild stimulant effect. The aim of the current study was to investigate the embryotoxic and teratogenic effects of the Khat extract using 60 female pregnant rats. These were divided to a Khat extract-treated group and a control group. Methanolic extract of Khat was orally given to the treated group 4 days before mating and up to day 16 of pregnancy with a dose of 100 mg/kg. Our results showed that significant number of embryos of the Khat-treated mothers were malformed and different in size and shape compared to embryos from the mothers of the control group. At day 8 of pregnancy, malformed embryos had ill developed primitive layers. By day 10 of pregnancy, neural tube and the somite were not formed compared to the control embryos. At later stages of pregnancy, embryos of the Khat-treated mothers appeared severely abnormal with opened neural groove and visceral pouches. Disrupted normal neural tube development, undifferentiated brain vesicles, incomplete closure of the brain flexures were also observed in these embryos. Highly significant increase in the number of the resorbed embryos of the Khat-treated mothers were observed (P < 0.01). The resorbed embryos appeared as a cellular collection in their placenta with some of their decidua had no visible embryonic tissues. In conclusions, Khat induced embryotoxic effects as well as severely affected the early normal embryonic development in rat.

RESUMEN: Catha edulis (Khat) es una planta floreciente. Una alta proporción de la población adulta en la Península Arábiga y el Cuerno de África la mastica por su efecto estimulante. El objetivo del presente estudio fue investigar los efectos embriotóxicos y teratogénicos del extracto de Khat utilizando 60 ratas hembras preñadas. Estas se dividieron en un grupo tratado con extracto de Khat y un grupo control. El extracto metanólico de Khat se administró por vía oral al grupo tratado 4 días antes del apareamiento y hasta el día 16 de preñez con una dosis de 100 mg / kg. Los resultados mostraron que una cantidad significativa de embriones de las madres tratadas con Khat tenían malformaciones y eran diferentes en tamaño y forma en comparación con los embriones de las madres del grupo control. En el día 8 de preñez, los embriones malformados tenían capas primitivas mal desarrolladas. Para el día 10 de preñez, el tubo neural y el somito no se formaron en comparación con los embriones del grupo control. En etapas posteriores de la preñez, los embriones de las madres tratadas con Khat parecían severamente anormales con surcos neurales abiertos y bolsas viscerales. También se observaron alteraciones en el desarrollo normal del tubo neural, vesículas cerebrales indiferenciadas y el cierre incompleto de las flexiones cerebrales en estos embriones. Se observó un aumento altamente significativo en el número de embriones reabsorbidos de las madres tratadas con Khat (P <0,01). Los embriones reabsorbidos aparecieron como una colección celular en su placenta con algunas de sus deciduas sin tejidos embrionarios visibles. Khat indujo efectos embriotóxicos y afectó severamente el desarrollo embrionario normal temprano en la rata.