Concentrations of pregnancy-associated glycoproteins in Water buffaloes females (Bubalus bubalis) during pregnancy and postpartum periods

The concentrations of pregnancy-associated glycoproteins (PAG) were determined in buffalo cows (Bubalus bubalis) using three different radioimmunoassay (RIA) systems (RIA-497, RIA-706, and RIA-708). Samples (10 mL) were collected by jugular venipuncture from Week 0 until Week 28 of pregnancy (9 females), and from parturition until Week 10 postpartum (13 females). During pregnancy, PAG molecules were detectable at Week 6 using the three aforementioned RIA systems (3.9 ± 1.3 ng/mL, 9.7 ± 1.3 ng/mL, and 9.9 ± 0.7 ng/mL for RIA-497, RIA-706, and RIA-708, respectively). These concentrations increased gradually until Week 28, reaching values of 39.6 ± 4.0 ng/mL (RIA-497), 50.5 ± 11.9 ng/mL (RIA-706), and 68.2 ± 20.8 ng/mL (RIA-708). PAG concentrations determined by RIA-497, RIA-706, and RIA-708 were strongly correlated throughout the entire gestation period, RIA-708 giving the higher concentrations. At parturition, the mean concentrations ranged from 34.9 ± 4.0 (RIA-497) to 84.7 ± 10.6 ng/mL (RIA-708). Thereafter, the concentrations decreased steadily, reaching very low levels (< 1.0 ng/mL) at Week 8 postpartum. In conclusion, PAG concentrations measured by the above three RIA systems showed a profile similar to those previously described in bovine species, with higher concentrations being detected by RIA-706 and RIA-708. However, the patterns of PAG concentrations, studied using the three aforementioned PAG-RIA systems, differed around parturition, with very low levels being observed in the female buffaloes