Uemura S, Nakanishi T, Matsuoka S, Friedman W F, Jarmakani J M
Pediatr Res. 1984 Dec;18(12):1277-81. doi: 10.1203/00006450-198412000-00010.
This study determines the inotropic effects of prostaglandin D2 (PGD2) and prostaglandin E1 (PGE1) in the isolated, arterial perfused newborn (NB) and adult (A) rabbit heart. Significant positive inotropism of PGD2 was observed at all concentrations studied (1 X 10(-17) to 1 X 10(-7) M) in the two age groups; the effect in the NB was significantly greater (p less than 0.05) than that in the A at PGD2 concentrations higher than 1 X 10(-17) M. Significant positive inotropism of PGE1 was observed at PGE1 concentrations higher than 1 X 10(-8) M in the NB, and only at 1 X 10(-6) M in the A. In the NB, the relaxation parameters [1/2 RT and the ratio of +dT/dt (max) to -dT/dt (max)] decreased to 80% of control after PGE1 infusion, but not after PGD2 infusion. In contrast, relaxation parameters in the A were not different from control. Propranolol (1 X 10(-6) M) did not alter the positive inotropic action of PGD2 and PGE1 in the NB. These data indicate that: 1) the positive inotropic effects of PGD2 and PGE1 in NB are greater than that in the A, 2) PGE1 and not PGD2, enhances myocardial relaxation only in the NB, 3) the contractile effects of PGD2 and PGE1 are not mediated by beta-receptors.
本研究测定了前列腺素D2（PGD2）和前列腺素E1（PGE1）对离体、动脉灌注的新生（NB）和成年（A）兔心脏的变力作用。在两个年龄组中，在所研究的所有浓度（1×10⁻¹⁷至1×10⁻⁷M）下均观察到PGD2具有显著的正性变力作用；在PGD2浓度高于1×10⁻¹⁷M时，NB组的作用显著大于A组（p＜0.05）。在NB组中，当PGE1浓度高于1×10⁻⁸M时观察到显著的正性变力作用，而在A组中仅在1×10⁻⁶M时观察到。在NB组中，输注PGE1后舒张参数[1/2 RT以及 +dT/dt（max）与 -dT/dt（max）的比值]降至对照值的80%，而输注PGD2后则未下降。相比之下，A组的舒张参数与对照无差异。普萘洛尔（1×10⁻⁶M）未改变PGD2和PGE1对NB心脏的正性变力作用。这些数据表明：1）PGD2和PGE1对NB心脏的正性变力作用大于对A心脏的作用；2）仅在NB心脏中，PGE1而非PGD2可增强心肌舒张；3）PGD2和PGE1的收缩作用不是由β受体介导的。
