FIG. 1.

Experimental design. (A) MSCs were harvested through endometrial biopsy from 7 mares on day 14 of the cycle before intrauterine infusion and were expanded in culture and labeled with CFDA SE. MSCs were then infused autologously into the uterus on day 4 of the cycle, followed by collection of endometrial cytology samples at 1, 3, and 6 h, blood samples at 6, 12, and 24 h, and endometrial biopsies at 24 h and 7 and 14 days after cell infusion. (B) Control mares (n = 4) received intrauterine PBS on day 4 of the cycle. The same follow-up sampling protocol was used as for the MSC infusion group except that only two biopsies were collected. MSCs, mesenchymal stromal cells; PBS, phosphate-buffered saline.