Fig. 2.

Effect of high-altitude hypoxia on phorbol 12,13-dibutyrate (PDBu)-induced contractions in UAs. Cumulative concentration-response curves to PDBu were determined in UAs obtained from nonpregnant and pregnant ewes with normoxia and long-term high-altitude hypoxia treatment in the absence or presence of PD-98059 (PD; 30 μM, pretreatment for 20 min). Data are expressed as percentages of contraction generated by 120 mM KCl, and each point represents the mean ± SE of tissues from 4–10 animals.