Diazinon interrupts ovarian steroidogenic acute regulatory (StAR) gene transcription in gonadotropin-stimulated rat model

Organophosphate pesticides are considered as endocrine disruptors that interfere with reproductive functions. The corpus luteum (CL) is a transient endocrine gland that produces progesterone, a crucial hormone for a successful beginning and maintenance of pregnancy. Steroidogenic acute regulatory protein (StAR) facilitates the rate-limiting transfer of cholesterol from the outer mitochondrial membrane to the inner organelle membranes. We investigated the effect of Diazinon (DZN), an organophosphate, on StAR mRNA expression by Sybergreen Real Time-PCR in a time-dependent manner in luteal phase. Fifty immature female Wistar rats (24-day-old) were injected with a single injection of Pregnant mare’s Serum Gonadotropin (PMSG) followed by a single injection of human Chorionic Gonadotropin (hCG), 48 hr later. Then, DZN was administered in a single dose (70 mg/kg bw, I.P); controls received only the vehicle, 12 hr post-hCG injection. Ovaries were collected in 4-hr intervals from 8 to 24 hr post-hCG injection. After, hCG stimulation transcript level of StAR gene were significantly altered in the hormone-stimulated rats following DZN treatment. In addition, histological study showed that the CL diameter in DZN-treated group was smaller than control group (p = 0.000). Our findings suggest that the critical step in the function of CL is disrupted by DZN and may correlates with female reproductive damage.