Fig. 5.

Effects of bafilomycin A1 on luteal cell size and P4 secretory function. (A) On PRG15, mother rats were administered with a single dose of bafilomycin A1 (Baf A1, 125 or 625 pg/rat) or vehicle intraovarian-bursally and were examined for luteal cell size in the ovarian tissue sampled on PRG18. Other rats were done with vehicle or Baf A1 (125 pg/rat) on PRG19 and were examined as well on PRG21. Cell size of luteal cells randomly selected (30 cells/CL, 3 CL/rat, ≥ 3 rats in each group) were quantitatively analyzed using Image J software and expressed as mean ± SEM. * P < 0.05, ** P < 0.01. (B) Rats treated with vehicle or Baf A1 (625 pg/rat) on PRG15 had blood taken at 0, 24, and 72 h after the drug challenge and were measured for their timing of parturition. Baf A1-treated dams were divided into three groups of delivery timing (advanced, before and in the evening of PRG22; normal, in the morning of PRG23; delayed, in and after the evening of PRG23). P4 levels in their circulating blood, relative to each on PRG15, are expressed as mean ± SEM (n = 9, the control group; n = 3–5, experimental groups). * P < 0.05.