Postnatal changes in β-adrenoceptors in the lung and the effect of hypoxia induced pulmonary hypertension of the newborn
| Autor: | Peter J. Barnes, Jayne A Reader, Judith C.W. Mak, David A. Kelly, Alison A. Hislop, Sheila G. Haworth |
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| Rok vydání: | 2002 |
| Předmět: |
Pharmacology
medicine.medical_specialty Lung business.industry Respiratory disease Vasodilation Hypoxia (medical) medicine.disease Pulmonary hypertension medicine.anatomical_structure Endocrinology Internal medicine Circulatory system Vascular resistance Medicine medicine.symptom business Blood vessel |
| Zdroj: | British Journal of Pharmacology. 135:1415-1424 |
| ISSN: | 0007-1188 |
| DOI: | 10.1038/sj.bjp.0704597 |
| Popis: | 1. beta-adrenoceptor activation leads to pulmonary vasodilatation. The increase in circulating catecholamines at birth may assist the postnatal fall in vascular resistance by their activation. To study beta(1)- and beta(2)-adrenoceptors during postnatal adaptation, we used [(125)I]-iodocyanopindolol (ICYP) binding to lung membranes and sections to quantify and locate the binding sites in piglets from birth to 14 days of age and compared them with those in adult pigs. In addition, pulmonary hypertension was induced in newborn piglets by hypobaric hypoxia. 2. In lung membranes the equilibrium dissociation constant (K(d)) did not change with age for total beta-adrenoceptors or for beta(2)-adrenoceptors, but there was a significant increase in maximum binding sites (B(max)) between birth and 3 days of age. On tissue sections, B(max) increased between 3 days and adulthood with no change in K(d). 3. Binding sites of beta(1)- and beta(2)-adrenoceptors were localized to the bronchial epithelium, to endothelium of extra- and intra-pulmonary arteries and to lung parenchyma. Total beta-adrenoceptor density increased with age at all locations (P |
| Databáze: | OpenAIRE |
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