Fig. 2.

Correlation between immediate PRL release and the PRL secretory rhythm. A: OVX rats were injected with saline (n = 8) or OT (n = 9) iv at 1600 of day 0 (arrow). Blood samples were taken immediately before and 5 and 10 min following peripheral injection and, thereafter, during the next 2 days to observe the PRL diurnal and nocturnal surges. B: same experimental design was repeated injecting rats with saline (n = 8) or TRH (n = 9). Data are presented as means ± SE. #P < 0.05 and ##P < 0.01 vs. control group at the same time. *P < 0.05 vs. 1600 PRL in the same experimental group.