Abstract: Objective To establish a stable cyclophosphamide(CTX) induced ovarian insufficiency rat model and to explore the mechanisms. Methods The survival curve of rats after intraperitoneal injection of different dosage of CTX was drawn and the optimal dose was determined. Sex hormone level, estrous cycle and ovarian histological change were further observed. The underlying mechanisms were explored by transcriptome sequencing. Results The mortality rate of medium and high dose in CTX group was high, so low dose CTX was chosen. After CTX exposure, E2 and AMH decreased(both P＜0.05),while FSH increased(P＜0.01). About half of the model rats showed irregular estrous cycles(P＜0.05). The preantral and antral follicles decreased(P＜0.01, P＜0.05), while atresia follicles increased (P＜0.01). Transcriptome sequencing analysis showed that differentially expressed genes (DEGs) between two groups functioned in channel activity and in transmembrane transporter activity. DEGs mainly enriched in neuroactive ligand-receptor interaction pathway, cAMP signal pathway and calcium signaling pathway, axon guidance. According to the protein-protein interaction network of DEGs,we screened out 14 hub genes. Among them, Leptin, Shh,Ntrk2,GRIN2A,CAMK2A,CaSR and Pvalb have been revealed to be closely related to ovarian function. Conclusions A POI rat model induced by CTX was successfully constructed; the neuroactive ligand-receptor interaction pathway, cAMP signal pathway, calcium signaling pathway and axon guidance pathway are enriched pathways. Lep, Shh, Ntrk2, GRIN2A, CAMK2A, CaSR and Pvalb are potentially key genes.

Key words: POI, cyclophosphamide, mechanisms