Abstract
To better understand the role of prostacyclin [prostaglandin (PG) I2] in oxygen mediation of vasomotor tone in the developing lung, we determined the ontogeny of the direct effects of acute changes in oxygen on in vitro PGI2 synthesis and adenosine 3',5'-cyclic monophosphate (cAMP) production in intrapulmonary arteries from fetal and newborn lambs. In the absence of varying oxygen, PGI2 synthesis increased 6.9-fold from early to late in the third trimester, and it rose an additional 3.2-fold from late gestation to 1 wk of age, and another 2.1-fold from 1 to 4 wk. PGE2 synthesis similarly rose 4.9-fold during the third trimester, but it then fell 69% from late gestation to 1 wk of age and remained unchanged postnatally. Paralleling the developmental increase in PGI2 synthesis, basal cAMP production rose 6.2- fold from the early third trimester to 4 wk of age. In contrast, PGI2- stimulated cAMP production was similar in all age groups. With an acute decline in PO2 in vitro from 680 to 40 mmHg, PGI2 and PGE2 synthesis in fetal arteries fell 33-46 and 39-55%, respectively. In contrast, they were increased by 9-145% and 44-130%, respectively, at lower PO2 in arteries from newborn lambs. Basal cAMP production was altered by decreased oxygen in a similar manner, falling by 35-39% in fetal arteries yet increasing by 21-47% in the newborn. PGI2-stimulated cAMP production, however, was not affected by oxygen at all ages except in the early third trimester. Thus there is a dramatic developmental increase in pulmonary arterial PGI2 synthesis that causes a marked maturational rise in cAMP production. In addition, decreased oxygen acutely attenuates PGI2 and PGE2 synthesis and cAMP production in fetal pulmonary arteries, whereas it enhances those processes in the newborn.
| Original language | English (US) |
|---|---|
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 265 |
| Issue number | 2 34-2 |
| State | Published - 1993 |
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Keywords
- adenylate cyclase
- cyclooxygenase
- hypoxic pulmonary hypertension
- prostaglandin E
ASJC Scopus subject areas
- Physiology
Cite this
Oxygen modulation of pulmonary arterial prostacyclin synthesis is developmentally regulated. / Shaul, P. W.; Farrar, M. A.; Magness, R. R.
In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 265, No. 2 34-2, 1993.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Oxygen modulation of pulmonary arterial prostacyclin synthesis is developmentally regulated
AU - Shaul, P. W.
AU - Farrar, M. A.
AU - Magness, R. R.
PY - 1993
Y1 - 1993
N2 - To better understand the role of prostacyclin [prostaglandin (PG) I2] in oxygen mediation of vasomotor tone in the developing lung, we determined the ontogeny of the direct effects of acute changes in oxygen on in vitro PGI2 synthesis and adenosine 3',5'-cyclic monophosphate (cAMP) production in intrapulmonary arteries from fetal and newborn lambs. In the absence of varying oxygen, PGI2 synthesis increased 6.9-fold from early to late in the third trimester, and it rose an additional 3.2-fold from late gestation to 1 wk of age, and another 2.1-fold from 1 to 4 wk. PGE2 synthesis similarly rose 4.9-fold during the third trimester, but it then fell 69% from late gestation to 1 wk of age and remained unchanged postnatally. Paralleling the developmental increase in PGI2 synthesis, basal cAMP production rose 6.2- fold from the early third trimester to 4 wk of age. In contrast, PGI2- stimulated cAMP production was similar in all age groups. With an acute decline in PO2 in vitro from 680 to 40 mmHg, PGI2 and PGE2 synthesis in fetal arteries fell 33-46 and 39-55%, respectively. In contrast, they were increased by 9-145% and 44-130%, respectively, at lower PO2 in arteries from newborn lambs. Basal cAMP production was altered by decreased oxygen in a similar manner, falling by 35-39% in fetal arteries yet increasing by 21-47% in the newborn. PGI2-stimulated cAMP production, however, was not affected by oxygen at all ages except in the early third trimester. Thus there is a dramatic developmental increase in pulmonary arterial PGI2 synthesis that causes a marked maturational rise in cAMP production. In addition, decreased oxygen acutely attenuates PGI2 and PGE2 synthesis and cAMP production in fetal pulmonary arteries, whereas it enhances those processes in the newborn.
AB - To better understand the role of prostacyclin [prostaglandin (PG) I2] in oxygen mediation of vasomotor tone in the developing lung, we determined the ontogeny of the direct effects of acute changes in oxygen on in vitro PGI2 synthesis and adenosine 3',5'-cyclic monophosphate (cAMP) production in intrapulmonary arteries from fetal and newborn lambs. In the absence of varying oxygen, PGI2 synthesis increased 6.9-fold from early to late in the third trimester, and it rose an additional 3.2-fold from late gestation to 1 wk of age, and another 2.1-fold from 1 to 4 wk. PGE2 synthesis similarly rose 4.9-fold during the third trimester, but it then fell 69% from late gestation to 1 wk of age and remained unchanged postnatally. Paralleling the developmental increase in PGI2 synthesis, basal cAMP production rose 6.2- fold from the early third trimester to 4 wk of age. In contrast, PGI2- stimulated cAMP production was similar in all age groups. With an acute decline in PO2 in vitro from 680 to 40 mmHg, PGI2 and PGE2 synthesis in fetal arteries fell 33-46 and 39-55%, respectively. In contrast, they were increased by 9-145% and 44-130%, respectively, at lower PO2 in arteries from newborn lambs. Basal cAMP production was altered by decreased oxygen in a similar manner, falling by 35-39% in fetal arteries yet increasing by 21-47% in the newborn. PGI2-stimulated cAMP production, however, was not affected by oxygen at all ages except in the early third trimester. Thus there is a dramatic developmental increase in pulmonary arterial PGI2 synthesis that causes a marked maturational rise in cAMP production. In addition, decreased oxygen acutely attenuates PGI2 and PGE2 synthesis and cAMP production in fetal pulmonary arteries, whereas it enhances those processes in the newborn.
KW - adenylate cyclase
KW - cyclooxygenase
KW - hypoxic pulmonary hypertension
KW - prostaglandin E
UR - http://www.scopus.com/inward/record.url?scp=0027178601&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027178601&partnerID=8YFLogxK
M3 - Article
VL - 265
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
SN - 0363-6135
IS - 2 34-2
ER -