Oxytocin-induced labor augments IL-1beta-stimulated lung fluid absorption in fetal guinea pig lungs.
*Labor; Absorption/drug effects; Amiloride/administration & dosage; Animals; Enzyme Activation/drug effects; Enzyme Inhibitors/administration & dosage; Epinephrine/metabolism; Extravascular Lung Water/*metabolism; Female; Fetal Organ Maturity/drug effects; Fetus/metabolism; Guinea Pigs; Hydrocortisone/metabolism; Induced; Interleukin-1/*administration & dosage/metabolism; Ion Transport/drug effects; Lung/*embryology; Maternal-Fetal Exchange/drug effects; Metyrapone/administration & dosage; Oxytocics/*administration & dosage; Oxytocin/*administration & dosage; Pregnancy; Propranolol/administration & dosage; Sodium Channel Blockers/administration & dosage; Sodium-Potassium-Chloride Symporters/metabolism; Vasodilator Agents/administration & dosage
We tested the hypothesis that oxytocin-induced labor augmented
Nair Prem K; Li Tianbo; Bhattacharjee Reshma; Ye Xin; Folkesson Hans G
American journal of physiology. Lung cellular and molecular physiology
2005
2005-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/ajplung.00256.2004" target="_blank" rel="noreferrer noopener">10.1152/ajplung.00256.2004</a>
IL-1beta stimulates alveolar fluid absorption in fetal guinea pig lungs via the hypothalamus-pituitary-adrenal gland axis.
Adrenocorticotropic Hormone/blood; Animals; Epinephrine/blood; Epithelial Sodium Channels; Extravascular Lung Water/*metabolism; Female; Guinea Pigs; Hydrocortisone/blood; Hypothalamo-Hypophyseal System/*physiology; Interleukin-1/blood/*pharmacology; Norepinephrine/blood; Pituitary-Adrenal System/*physiology; Pregnancy; Pulmonary Alveoli/*drug effects/embryology/*metabolism; Sodium Channels/metabolism; Sodium-Potassium-Exchanging ATPase/metabolism
We tested the hypothesis that interleukin (IL)-1beta-induced cortisol synthesis stimulates alveolar fluid clearance in preterm fetuses. IL-1beta was administered subcutaneously daily to timed-pregnant guinea pigs for 3 days with and without simultaneous cortisol synthesis inhibition by metyrapone. Fetuses were obtained by abdominal hysterotomy at 61 and 68 days gestation and instilled with isosmolar 5% albumin in the lungs, and alveolar fluid movement was measured over 1 h from the change in alveolar protein concentration. Alveolar fluid clearance was induced at 61 days gestation and stimulated at 68 days gestation by IL-1beta, which both were attenuated by cortisol synthesis inhibition. Plasma ACTH and cortisol concentrations were increased by IL-1beta at both gestational ages, and metyrapone reduced cortisol concentrations. IL-1beta was mostly low or undetectable in both fetal and maternal blood. Prenatal alveolar fluid clearance, when present as well as IL-1beta induced, was always propranolol and amiloride sensitive, suggesting that beta-adrenoceptor stimulation and amiloride-sensitive Na+ channels were critical for fluid absorption. IL-1beta increased lung beta-adrenoceptor density at gestation day 61, and cortisol synthesis inhibition attenuated the increased beta-adrenoceptor density. Epithelial Na+ channel and Na+-K+-ATPase subunit expressions were both increased by IL-1beta and attenuated by cortisol synthesis inhibition. These results may explain why babies delivered preterm after intrauterine inflammation have a reduced risk of developing severe respiratory distress.
Ye Xin; Acharya Reshma; Herbert Jonathan B; Hamilton Sarah E; Folkesson Hans G
American journal of physiology. Lung cellular and molecular physiology
2004
2004-04
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/ajplung.00214.2003" target="_blank" rel="noreferrer noopener">10.1152/ajplung.00214.2003</a>
Stimulation of distal airspace fluid clearance in guinea pigs involves bumetanide-sensitive ion transport.
*Ion Transport; Absorption; Adrenergic; Adrenergic beta-Antagonists/pharmacology; Animals; beta/physiology; Body Fluids/*metabolism; Bumetanide/*pharmacology; Diuretics/*pharmacology; Epinephrine/blood; Epithelium; Fetus/metabolism; Gestational Age; Guinea Pigs; Lung/*embryology/metabolism; Newborn; Propranolol/pharmacology; Receptors
OBJECTIVE: This study was undertaken to test the hypothesis that beta-adrenoceptor stimulation of fetal lung fluid absorption in near-term guinea pig fetuses involves bumetanide-sensitive ion transport. STUDY DESIGN: Fetuses were obtained from timed-pregnant guinea pigs at 61 to 69 days' gestation with and without oxytocin-induced preterm labor. The fetuses were placed on continuous positive airway pressure oxygenation, and an isosmolar 5% albumin solution was instilled into the lungs. Distal airspace fluid clearance was measured over 1 hour from the increase in distal airspace protein concentration as fluid was reabsorbed with and without the Cl(-) transport inhibitor bumetanide. RESULTS: Fetal lungs began to absorb distal airspace fluid at 64 to 66 days' gestation, and at birth, distal airspace fluid clearance rapidly quadrupled. Labor induction by oxytocin stimulated distal airspace fluid clearance. Distal airspace fluid clearance, when present, was sensitive to propranolol-inhibition and depended on beta-adrenoceptor stimulation. Fluid secretion at 61 days' gestation was reduced by bumetanide instillation. Bumetanide addition was only inhibitory when distal airspace fluid clearance was propranolol-sensitive. CONCLUSION: Beta-adrenoceptor stimulation from endogenous fetal epinephrine increased fetal distal airspace fluid clearance and involved bumetanide-sensitive ion transport.
Ye Xin; Norlin Andreas; Folkesson Hans G
American journal of obstetrics and gynecology
2004
2004-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.ajog.2003.09.074" target="_blank" rel="noreferrer noopener">10.1016/j.ajog.2003.09.074</a>