Response of Granulosa Cell Gap Junctions to Human Chorionic Gonadotropin (hCG) at Ovulation

Abstract

Granulosa cell gap junctions in the mammalian follicle are dynamic bimembranous

Reduction of connexin 43 in human cumulus cells yields good embryo competence during ICSI

“…Previous studies demonstrated an increase in the amount of Cx43 in the large antral follicles in a stage at which serum concentrations of FSH are relatively elevated [16,17]. On the other hand, the preovulatory surge of serum concentrations of LH is followed by a drop at the level of Cx43 mRNA and reduction in the amount of its corresponding protein [3,[16][17][18][19]. In equine, porcine and rat cumulus cells, initiation of meiotic resumption is associated with reduction of Cx43 protein levels [7,20,21].…”

Expression of connexin 43 and gap junctional intercellular communication in the cumulus–oocyte complex in sheep

“…In addition, exposure of the follicle to LH or human chorionic gonadotropin (hCG) causes the interruption of ionic coupling between granulosa/cumulus cells and the oocyte (Larsen et al 1981(Larsen et al , 1986). In agreement with other researchers, we saw a decrease in GJIC of cumulus cells from large follicles following incubation with LH (Larsen et al 1981(Larsen et al , 1986. Several studies have indicated that in oocytes nearing ovulation, there is a decrease in junctional coupling (Larsen et al 1986, Chen et al 1990).…”

Enzyme cytochemical and morphometrical analyses of gap junctions in rabbit ovarian granulosa cells during follicle maturation and ovulatory process.

“…Larsen et al (18) reported that FSH modulates granulosa cell gap junctions during early follicle growth and hCG during the preovulatory stage of follicle growth. Merk et al (23) showed that estrogen stimulates the formation and internalization of gap junctions.…”

“…The other is the annular gap junction, which refers to the portion of junction isolated within individual granulosa cells. These two types of gap junctions are modulated by gonadotropins (18,23) or steroid hormones (7,23), and change in size and frequency during the follicle maturation and ovulatory process (4,9).…”