Exhaled Oral and Nasal Nitric Oxide during L-Arginine Infusion in Preeclampsia

• Published in: Gynecologic and obstetric investigation Vol. 46; no. 4; pp. 232 - 237
• Main Authors: Grunewald, Charlotta, Carlström, Kjell, Kumlien, Gunilla, Ringqvist, Åsa, Lundberg, Jon
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Karger 01.01.1998; S. Karger AG
• Subjects: Adult; Arginine - metabolism; Biological and medical sciences; Blood Pressure; Breath Tests; Cyclic GMP - blood; Female; Genital system. Reproduction; Heart Rate; Humans; Luminescent Measurements; Medical sciences; Medicin och hälsovetenskap; Mouth; Nitrates - blood; Nitric Oxide - analysis; Nitric Oxide - biosynthesis; Nose; Original Paper; Pharmacology. Drug treatments; Pre-Eclampsia - metabolism; Pregnancy; L-Arginine; Exhaled air; Platelets; Nitric oxide; Cyclic guanosine monophosphate; Human; Hypertension; Measurement; Expired air; Pregnancy disorders; Cardiovascular disease; 3',5'-GMP; Chemiluminescence; Precursor; Pregnancy toxemia; Blood plasma; Oral cavity; Arginine; Perfusion; Nose; Preeclampsia; Female; Influence; Arterial pressure
• ISSN: 0378-7346; 1423-002X
• DOI: 10.1159/000010040

Objective: To determine the effects of the nitric oxide (NO) precursor L-arginine on the airway NO concentration in patients with preeclampsia. Methods: NO was measured by a noninvasive chemiluminescence technique in air sampled directly from nasal and oral cavities during expiration before and during L-arginine infusion in 9 preeclamptic and 10 control pregnancies. Maternal blood pressure and heart rate were simultaneously recorded, and blood was sampled for analyses of cyclic guanosine monophosphate (cGMP) and nitrate. Results: Basal nasal and orally exhaled NO and the increment in nasal NO concentration during L-arginine infusion were similar in both groups. Basal plasma and platelet cGMP concentrations were similar in both groups. Following L-arginine infusion, plasma cGMP levels were significantly higher in preeclamptics (p < 0.01), while platelet cGMP was unaffected in both groups. Basal plasma nitrate was significantly higher in preeclamptics (p < 0.01), and this difference was not altered following infusion. Blood pressure and heart rate remained unaffected by the procedure in both groups. Conclusions: Blood pressure did not decrease in the preeclamptics following L-arginine infusion, despite a significant increase in nasal NO sampled during breathhold and a concomitant increase in plasma cGMP, possibly reflecting an endogenous NO production. These results do not support the idea of a generalized decrease in NO production being a major cause of hypertension in preeclampsia.