Effects of RN-1734 injection into hypothalamus PO/AH region on increase of rat body temperature induced by progesterone / 中国药理学通报

ABSTRACT

Aim: To verify the involvement of transient receptor potential vanilloid 4 (TRPV4) in the process of progesterone induced body temperature rise in female rats during their sexual cycle. Methods: The body temperature and progesterone concentration at different stages of the normal female rats' sexual cycle were measured. The ovariectomized rats were given different doses of progesterone and their body temperature were measured. Female rats were administered with RN-1734, a specific antagonist of TRPV4 in the preoptic-anterior hypothalamus area (PO/AH) at the metestrus to observe the change of rats body temperature. Furthermore, RN 1734 was injected into the PO/AH area of ovariectomized rats which were preinjected with progesterone. The effect of progesterone on the body temperature of rats and the fluctuation of body temperature after blocking TRPV4 were observed. Results: There was a positive correlation between body temperature and progesterone doses in female rats at different stages of estrus cycle. In ovariectomized rats, different doses of progesterone were administered, indicating a dose-dependent increase in body temperature. RN- 1734 was injected to PO/AH 2 hours before the maximum body temperature on normal metestrus rats. It was observed that the increase range of body temperature decreased significantly after RN-1734 injection. This study also showed that RN-1734 significantly reduced the increase range of body temperature in ovariectomized rats administered with progesterone. Conclusions: The specific antagonist TRPV4 injected into the thermoregulation center could reduce the increase of body temperature in metestrus of normal rats, suggesting that TRPV4 may be involved in the process of the increase of rat body temperature induced by progesterone.