COX-2 Expression in Tissues of Pregnant Cows
Total RNA was prepared from myometrium, endometrium, caruncles, fetal cotyledons, and cervical mucosa (n = 3). Amnion and chorioallantoic membranes were examined only from term pregnant animals. It was necessary to use 20 ^g of total RNA for each hybridization reaction to obtain detectable signals from tissues other than cotyledons and caruncles. Autoradiography was performed on BioMax films with enhancing screens with 3- to 7-day exposure times. antibiotic levaquin
Figure 1 shows a representative gel for COX-2 mRNA and GAPDH mRNA measurements by RPA in tissues from the placentomes. On Day 150, distinct signals for COX-2 mRNA were detected in RNA from fetal cotyledons, whereas signals for COX-2 mRNA in caruncles were very weak. On Day 275, expression of COX-2 mRNA was clearly detectable also in caruncles. Concentrations of COX-2 mRNA in both the cotyledons and caruncles increased with advancing gestation and were greatest at term, but there was no demonstrable difference between samples from cows in labor (Day 280+) and those not in labor (Day 280-). COX-2 mRNA expression in caruncles declined rapidly after parturition; in samples taken at 6-12 h postpartum, the signals were considerably weaker than at parturition. Cotyledons from postpartum cows were not available for assay.
FIG. 1. RPA for COX-2 mRNA in samples of bovine caruncles and cotyledons obtained at Days 150, 275, 280- (term, no labor), and 280+ (term, labor) of gestation, and of caruncles at postpartum Day 1. Tissues from two animals are shown for each day. Length of protected fragment for COX-2 was 2 74 bases and for GAPDH was 198 bases. Messenger RNA from caruncles is in lanes 1-10; that from cotyledons is in lanes 11-18; stage of gestation is indicated on the figure. The remaining lanes show undigested and digested probes and molecular size marker.