Abstract: 【Objective】 To explore the interacting effect of NT3 and LIF on the survival and initiation of primordial follicles

and investigate the possible mechanism underlying NT3 contributes to follicular development. 【Methods】 Ovaries from 4 day-old rats were cultured for 14 days in the basic medium supplemented with NT3

LIF alone or combined. Fresh (fresh control

FC) and basic medium cultured (cultured control

CC) ovaries were set as controls. The developmental stages and viability of follicles were assessed using histomorphology and TUNEL labeling. Immunohistochemistry for PCNA was performed to evaluate the mitotic activity of granulosa cells. Measurement of androstenedione and estradiol in the medium was performed and the expression of KL mRNA in the ovary was examined. 【Results】 After culture

follicles sustained healthy and less apoptotic cells were found in the presence of NT3 or LIF. Furthermore

the proportion of developmental follicles increased and the percentage of granulose cells that stained for PCNA was significantly higher. However

when combined NT3 with LIF

no obvious additional effect was found. The expression of KL mRNA in the NT3

LIF

NT3+LIF group is 3.38±0.43

2.02±0.20

2.07±0.21 times higher than in the CC group. 【Conclusion】 NT3

LIF alone or combined had a stimulative effect on the survival and development of primordial follicles. However

there was no obvious synergistic or additional effect between LIF and NT3. One of the mechanisms of NT3 underlying the initiation of primordial follicles might activate c-kit/KL interactions.