Developmental change in isoproterenol-mediated relaxation of pulmonary veins of fetal and newborn lambs
| Autor: | Michael Botello, Jean-Francois Tolsa, Yuansheng Gao, J. Usha Raj |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Agonist
medicine.medical_specialty Vascular smooth muscle Physiology medicine.drug_class Muscle Relaxation 8-Bromo Cyclic Adenosine Monophosphate Vasodilation Biology Developmental change Muscle Smooth Vascular Pulmonary vein Fetus Physiology (medical) Internal medicine medicine Cyclic AMP Animals Sheep Colforsin Isoproterenol Propranolol β adrenergic agonist medicine.anatomical_structure Endocrinology Animals Newborn Pulmonary Veins 15-Hydroxy-11 alpha 9 alpha-(epoxymethano)prosta-5 13-dienoic Acid cardiovascular system Blood vessel Adenylyl Cyclases |
| Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 84(5) |
| ISSN: | 8750-7587 |
| Popis: | β-Adrenergic agonists are important regulators of perinatal pulmonary circulation. They cause vasodilation primarily via the adenyl cyclase-adenosine 3′,5′-cyclic monophosphate (cAMP) pathway. We examined the responses of isolated fourth-generation pulmonary veins of term fetal (145 ± 2 days gestation) and newborn (10 ± 1 days) lambs to isoproterenol, a β-adrenergic agonist. In vessels preconstricted with U-46619 (a thromboxane A2analog), isoproterenol induced greater relaxation in pulmonary veins of newborn lambs than in those of fetal lambs. The relaxation was eliminated by propranolol, a β-adrenergic antagonist. Forskolin, an activator of adenyl cyclase, also caused greater relaxation of veins of newborn than those of fetal lambs. 8-Bromoadenosine 3′,5′-cyclic monophosphate, a cell membrane-permeable analog of cAMP, induced a similar relaxation of all vessels. Biochemical studies show that isoproterenol and forskolin induced a greater increase in cAMP content and in adenyl cyclase activity of pulmonary veins in the newborn than in the fetal lamb. These results demonstrate that β-adrenergic-agonist-mediated relaxation of pulmonary veins increases with maturation. An increase in the activity of adenyl cyclase may contribute to the change. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|