Effect of dexamethasone on pulmonary and renal angiotensin-converting enzyme concentration in fetal sheep during late gestation

Zimmermann, Heiner; Gardner, David S.; Jellyman, Juanita K.; Fowden, Abigail L.; Giussani, Dino A.; Forhead, Alison J.

Abstract

OBJECTIVES:
The effect of dexamethasone on tissue angiotensin-converting enzyme (ACE) was investigated in fetal sheep.

STUDY DESIGN:
Pulmonary and renal ACE concentrations were measured in 16 sheep fetuses at between 127 and 131 days of gestation (term 145 ± 2 days): 6 were untreated, whereas 10 were chronically catheterized and infused intravenously with either saline solution (0.9%, n = 4) or dexamethasone (45-60 μg · kg-1 · d-1, n = 6) for the previous 2 days. The dexamethasone dose increased plasma dexamethasone to around one fifth of that measured in newborn human infants delivered after maternal dexamethasone treatment.

RESULTS:
Over the period of infusion, arterial blood pressure increased significantly in the dexamethasone (+6.8 ± 1.5 mm Hg, P < .05) but not saline-treated fetuses (+1.6 ± 0.6 mm Hg). At delivery, pulmonary ACE in the dexamethasone-infused fetuses (1.24 ± 0.26 nmoles hippurate · min-1 · mg protein-1) was significantly greater than in the control fetuses (0.50 ± 0.07 nmoles · min -1 · mg protein-1, P < .005); renal ACE was unchanged by dexamethasone treatment. Overall, pulmonary ACE and blood pressure were correlated on the last day of infusion (r = 0.70, P < .05).

CONCLUSION:
The rise in pulmonary ACE seen in dexamethasone-treated sheep fetuses may contribute, in part, to the glucocorticoid-induced increase in blood pressure.

Citation

Zimmermann, H., Gardner, D. S., Jellyman, J. K., Fowden, A. L., Giussani, D. A., & Forhead, A. J. (2003). Effect of dexamethasone on pulmonary and renal angiotensin-converting enzyme concentration in fetal sheep during late gestation. American Journal of Obstetrics and Gynecology, 189(5), 1467-1471. https://doi.org/10.1067/S0002-9378%2803%2900627-6

• Journal Article Type: Article
• Acceptance Date: May 14, 2003
• Publication Date: 2003-11
• Deposit Date: Mar 5, 2025
• Journal: American Journal of Obstetrics and Gynecology
• Print ISSN: 0002-9378
• Electronic ISSN: 1097-6868
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 189
• Issue: 5
• Pages: 1467-1471
• DOI: https://doi.org/10.1067/S0002-9378%2803%2900627-6
• Keywords: Glucocorticoids, lung, kidney, blood pressure, fetus, sheep
• Public URL: https://nottingham-repository.worktribe.com/output/3085428
• Publisher URL: https://www.ajog.org/article/S0002-9378(03)00627-6/abstract