Morphologic observation and classification criteria of atretic follicles in guinea pigs

Abstract

Abstract:There is a lack of appropriate classification criteria for the determination of atretic follicles in guinea pigs. In the present study, new criteria were established based on the latest morphologic criteria for cell death proposed by the Nomenclature Committee on Cell Death (NCCD) in 2009. Ovaries of guinea pigs were sampled on different stages of estrous cycle, and the morphologic observations of atretic follicles were investigated in serial sections. The results showed that the process of follicular atresia could be classified into four continuous stages: (1) the granulosa layer became loose, and some apoptotic bodies began to appear; (2) the granulosa cells were massively eliminated; (3) the theca interna cells differentiated; and (4) the residual follicular cells degenerated. In addition, the examination revealed that these morphologic criteria were accurate and feasible. In conclusion, this study provides new criteria for the classification of atretic follicles in guinea pigs, and this knowledge can inform future research in the area.

Expression characteristics of MMP-2 and MMP-9 in guinea pig ovaries during the estrous cycle

“…A normal estrous cycle is divided into four stages: proestrus, estrous, metestrus, and diestrus (Wang et al, 2010). The four stages are obviously affected by estrogen periodicity (Bland, 1980).…”

Induction of follicular luteinization by equine chorionic gonadotropin in cyclic guinea pigs

“…A similar conclusion was reported in guinea pigs by Rawson et al (1979): the conversion of normal follicles to atretic ones reflected the LH activity of the eCG. Previous works suggested that follicular luteinization and atresia in guinea pigs might be complex and differ from the processes in other mammals (Wang et al, 2010a;2010b). Certainly, the dependence on the selection of antral follicles in guinea pigs warrants further studies, which should allow this system to become a more informative model.…”

“…6) were significantly different among the groups (P<0.05) and were in the following sequence: 50 IU group>20 IU group>control group. According to relevant revised classification criteria (Wang et al, 2010b), the follicular atresia and oocyte degeneration in the control group were at the latter Stage III (Fig. 7a) or Stage I (Fig.…”

“…Guinea pigs, only ovulate a few oocytes (3.6±0.1) in one typical estrous cycle (Suzuki et al, 1993), and the majority of follicles are lost by atresia (Hermreck and Greenwald, 1964) in the four continuous stages (Wang et al, 2010b). Gonadotropins do not always reliably induce superovulation in guinea pigs (Suzuki et al, 2003), and the mechanism of ovulation remains poorly understood.…”

Effects of exogenous 17β‐estradiol on follicular development in the neonatal and immature mouse in vivo

“…The specific protein immunoreactivity was visualized with 0.05% DAB in 10 mM PBS containing 0.01% (V/V) H 2 O 2 for 30 min, and counterstained with hematoxylin. The negative control was normal rabbit serum (NRS) instead of primary antibody, and relative levels of immunostaining were evaluated and repeated at least four times [28][29][30][31]. The images were captured under the microscope.…”