02981naa a2200265 a 450000100080000000500110000800800410001902200140006002400380007410000190011224501550013126000090028650003060029552018470060165300110244865300100245965300230246965300130249270000210250570000200252670000190254670000190256570000170258477301140260110643622023-10-27       2023    bl uuuu     u00u1 u    #d  a1642-431X7 a10.1016/j.repbio.2023.1008132DOI1 aCAMOZZI, M.G.M  aCystic endometrial hyperplasia-pyometra syndrome impairs the preantral follicle reserve in domestic bitches (Canis familiaris).h[electronic resource]  c2023  aArticle history: Received 19 February 2023; Received in revised form 25 September 2023; Accepted 27 September 2023; Available online 11 October 2023. -- Corresponding author: Alves, B.G.; Postgraduate Program in Animal Bioscience, Federal University of Jataí, GO, Brazil; email:bennervet@gmail.com --  aCystic endometrial hyperplasia (CEH)-pyometra syndrome is the most common uterine pathological condition reported in breeding bitches, however, their described effects on fertility are limited to uterine disorders and conception rates. As the preantral follicle population represents the available reserve of gametes recruited during the lifespan, the aim of this study was to evaluate the effects of CEH-pyometra syndrome on the: (i) preantral follicle morphology, (ii) developing follicle rates, and (iii) preantral follicle and stromal cell densities. Ovarian fragments from bitches subjected to elective or therapeutic ovariohysterectomy were allocated according to uterine diagnosis as follows: control (n = 7, clinically healthy), CEH-mucometra (n = 8, uterine lumen filled with a sterile mucus), and pyometra (n = 17, presence of a purulent mucus) groups. Overall, the control group had 3.4 and 4.1-fold higher probability (P < 0.0001) of the presence of normal preantral follicles compared with CEH-mucometra and pyometra groups, respectively. Moreover, ovarian fragments from the pyometra group showed an increase in the percentage of developing follicles (P < 0.05) compared to the control. Both CEH-mucometra and pyometra groups showed lower (P < 0.05) preantral follicle and stromal cell densities (P < 0.05) compared to the control. In summary, the CEH-pyometra syndrome decreased the percentage of morphologically normal follicles and enhanced the developing follicle rates. Additionally, a reduction of preantral follicle and stromal cell densities suggests that the inappropriate uterine environment induced by CEH-pyometra syndrome can lead to premature depletion of ovarian reserve. © 2023 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn  aCanine  aOvary  aPreantral follicle  aPyometra1 aSATURNINO, K. C.1 aMACHADO, M.R.F.1 aGASTAL, G.D.A.1 aMOREIRA, C. N.1 aALVES, B. G.  tReproductive Biology, December 2023, Volume 23, Issue 4, 100813. https://doi.org/10.1016/j.repbio.2023.100813