2-2--(hydroxynitrosohydrazono)bis-ethanamine and Hypertension--Pulmonary

To determine the selective vasodilatory effects of two inhaled "NONOate" aerosols in a closed chest pig model of acute pulmonary hypertension (APH).. APH was induced by IV infusion of the prostaglandin H(2)/thromboxane A(2) receptor agonist (U46619). Aerosolized diethylenetriamine nitric oxide (NO) adduct (DETA/NO, n = 4), dipropylenetriamine NO adduct (DPTA/NO, n = 4) [60 micro mol each], or placebo (n = 4) was delivered via the trachea. Hemodynamic parameters and blood samples were measured before and after inhalation therapy.. Compared to control animals, pulmonary vascular resistance and pulmonary arterial pressure were significantly reduced from 10 to 105 min after DETA/NO administration and from 10 to 45 min after DPTA/NO aerosol administration (p < 0.05). Both aerosols had no significant effect on systemic vascular resistance or systemic BP. Serum nitrite significantly increased after the inhalation of both NONOates (p < 0.01). There was a tendency for reduced intrapulmonary shunting, particularly after treatment with DETA/NO.. Both DETA/NO and DPTA/NO administered as aerosols selectively reduced pulmonary hypertension induced by U46619.

Topics: Aerosols; Alkenes; Analysis of Variance; Animals; Female; Hemodynamics; Hypertension, Pulmonary; Nitric Oxide Donors; Nitroso Compounds; Pulmonary Gas Exchange; Respiratory Distress Syndrome; Swine; Vasodilator Agents

Inhaled nitric oxide (NO) has been administered to animals to selectively reduce pulmonary hypertension via NO donors such as the NONOates. However, vectorial Na(+) transport across confluent monolayers of alveolar type II (ATII) pneumocytes has been decreased by NO. We tested the hypothesis that administration of the NO donor, DETANONOate, would decrease alveolar fluid clearance (AFC) in the rabbit in vivo. We instilled a solution of 5% albumin in 0.9% NaCl with 3 mM DETANONOate into anesthetized rabbits. Two hours later, similar AFC values were measured in the presence and absence of 3 mM DETANONOate (38 +/- 12% versus 43 +/- 13%; mean +/- SD). However, animals coadministered 1 mM amiloride with one of three doses of DETANONOate (100 microM, 300 microM, or 3 mM) had significantly (p < 0.05) greater AFC values (23 +/- 8, 20 +/- 14, 28 +/- 12%, respectively) than those administered amiloride alone (10 +/- 7%). When 5% albumin in a Cl(-)-free solution was administered in the presence or absence of 100 microM DETANONOate, neither AFC values nor alveolar Cl(-) concentrations were different. DETANONOate decreases the amiloride-sensitive fraction of AFC but does not decrease total AFC. DETANONOate does not influence total AFC secondary to an increase in the amiloride-insensitive fraction of AFC that is not associated with a decrease in alveolar Cl(-) secretion.

Topics: Amiloride; Animals; Diuretics; Hypertension, Pulmonary; Male; Nitric Oxide; Nitric Oxide Donors; Nitroso Compounds; Pulmonary Alveoli; Rabbits

Nitric oxide (NO) is an important endogenous regulatory molecule implicated in both proinflammatory and antiinflammatory processes in the lung. Previously, we demonstrated that in human alveolar macrophages (AM), NO decreased inflammatory cytokine production, including that of interleukin-1beta, tumor necrosis factor-alpha and macrophage inflammatory protein-1alpha. One mechanism by which NO could regulate such diverse cytokine production is through effects on the transcription factor nuclear factor-kappaB (NF-kappaB), which controls the expression of the genes for these inflammatory cytokines and growth factors. We therefore investigated whether NO affects NF-kappaB activation in AM in vitro and in vivo. In vitro studies with AM showed that NF-kappaB activation by lipopolysaccharide (LPS) is decreased by NO in a dose-dependent manner. NO prevented an LPS-mediated decrease in the NF-kappaB inhibitory protein IkappaB-alpha. In asthma, airway NO levels are increased, whereas in primary pulmonary hypertension (PPH), airway NO levels are lower than in healthy lungs. In vivo investigations were conducted with freshly isolated AM from healthy controls, asthmatic individuals, and PPH patients. Healthy individuals had airway NO levels of 8 +/- 2 ppb (mean +/- SEM), which is associated with low NF-kappaB activation. Asthma patients with airway NO levels > 17 ppb showed minimal NF-kappaB activation, whereas asthmatic individuals with NO levels

Topics: Asthma; Bronchoalveolar Lavage Fluid; Case-Control Studies; Dose-Response Relationship, Drug; Down-Regulation; Humans; Hypertension, Pulmonary; Lipopolysaccharides; Macrophages, Alveolar; NF-kappa B; Nitric Oxide; Nitroso Compounds; Tumor Necrosis Factor-alpha