Objective

2

To investigate the effect of Ranae Oviductus (RO) on ovarian follicular development， phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway， and pregnancy function in rats

and the estrogen-like mechanism of OR.

Method

2

Seventy female Wistar rats were randomly divided into a normal group， a progynova+ luteohormone group (1 mg·kg

-1

+40 mg·kg

-1

)

a clomiphene group (10 mg·kg

-1

)

and high-dose(400 mg·kg

-1

) and low-dose(200 mg·kg

-1

) RO groups. Rats were administered correspondingly by gavage for eight weeks. After seven weeks of intragastric administration

the estrus cycle of all rats was measured. After eight weeks of intragastric administration， four rats from each group were selected to give birth. For other rats

blood was collected on the day of estrus， and the serum levels of estradiol (E

2

)，progesterone (P)， testosterone (T)， follicle-stimulating hormone (FSH)， and luteotropic hormone (LH) were detected. Uterus and ovaries were extracted and weighed to calculate organ index. One ovary was made into pathological sections

and the follicles at different developmental stages and corpus luteum were counted. Real-time fluorescence-based quantitative polymerase chain reaction（Real-time PCR）and Western blot were performed on the other ovary to detect mRNA and protein changes in the PI3K/Akt signaling pathway. Forty female Kunming mice were randomly divided into a normal group and RO groups (400 mg·kg

-1

) with 14 days， 28 days， and 56 days of intervention. Mice in the RO groups were raised with male mice in cages after intragastric administration of OR for 14， 28， and 56 days， respectively. After 18 days

the number of intrauterine fetuses on both sides and the number of stunted fetuses were counted.

Result

2

After eight weeks of intragastric administration of OR， the rats showed decreased uterine index (

P

<

0.05)， declining serum LH (

P

<

0.05)， reduced luteum (

P

<

0.01)， dwindled primary follicles (

P

<

0.05)， and increased rate of follicle atresia (

P

<

0.01). Additionally， more luteal or interstitial glands degenerated into interstitial structures in the ovarian cortex in a short time. The mRNA expression levels of PI3K and Akt in the ovary were elevated (

P

<

0.01)， while the mRNA expression levels of mTOR and PTEN were reduced (

P

<

0.01). The phosphorylation level of Akt protein showed a downward trend without significant difference. For the rats， the number of fetuses was decreased (

P

<

0.05). The pregnancy rate of mice was decreased to varying degrees after administration of RO for different durations， with the lowest in the 14 day RO group， as low as 30%. After 28 days of intragastric administration of RO， the difference in left and right uterine pregnancy increased (

P

<

0.05).

Conclusion

2

Long-term administration of RO can lead to premature ovarian failure by over-stimulating the ovary， which is similar to clomiphene. Short-term administration can result in decreased pregnancy rate， excessive ovulation on one side， and inhibition of ovulation on the other side. The influence on follicles needs further exploration.