Skip to main content
. Author manuscript; available in PMC: 2009 Nov 1.
Published in final edited form as: Pediatr Res. 2008 Nov;64(5):477–481. doi: 10.1203/PDR.0b013e3181827c2c

Figure 3.

Figure 3

Higher concentrations of PDE1, 3 and 4 inhibitors are required to inhibit isometric tension in the mature ductus arteriosus (■) than in the immature ductus (○). Ductus rings were precontracted with 30% oxygen, indomethacin and L-NAME (see Methods). Dose responses for 8-MM-IBMX, cilostamide, milrinone, rolipram, and MY5445 were studied. Tension is expressed as a percentage of baseline Net Tension (see Methods). (*): p<0.05, EC50 (immature) < EC50 (mature). n= number of separate animals used. 8-MM -IBMX: EC50 (immature) = 0.4±0.4 × 10−4M (n= 6); EC50 (mature) = 1.5±0.7 × 10−4M (n= 5), p<0.05. Cilostamide: EC50 (immature) = 2.9±0.8 × 10−7M (n= 4); EC50 (mature) = 8.4±1.5 × 10−7M (n= 4), p<0.05. Milrinone: EC50 (immature) = 0.7±0.1 × 10−6M (n= 6); EC50 (mature) = 9.4±2.2 × 10−6M (n= 7), p<0.05. Rolipram: EC50 (immature) = 0.7±0.1 × 10−4M (n= 6); EC50 (mature) = 1.3±0.1 × 10−4M (n= 7), p<0.05. MY5445: EC50 (immature) = not measurable (n= 4); EC50 (mature) = not measurable (n= 4).