Ragweed sensitization alters pulmonary vascular responses to bronchoprovocation in beagle dogs

Abstract

In ragweed (RW)-sensitized beagle dogs, we tested the hypothesis that reactivity of the pulmonary vasculature was enhanced with aerosolized histamine (Hist) and RW. Seven dogs were neonatally sensitized with repeated intraperitoneal RW injections, and 12 dogs were controls (Con). The dogs were anesthetized with intravenous chloralose, mechanically ventilated, and instrumented with femoral arterial and pulmonary artery catheters. Specific lung compliance (CLsp), specific lung conductance (Gsp), systemic vascular resistance index, and pulmonary vascular resistance index (PVRI) were measured before and after bronchoprovocation with Hist and RW. After Hist inhalation (5 breaths of 30 mg/ml), both Con and RW dogs had significant (P < 0.05) decreases in CLsp (-51 +/- 4 and -53 +/- 5%, respectively) and Gsp (-65 +/- 5 and -69 +/- 3%, respectively), but only RW-sensitized dogs had a significant increase in PVRI (38 +/- 10%). After RW inhalation (60 breaths of 0.8 mg/ml), only RW-sensitized dogs had significant increases (62 +/- 20%) in PVRI and decreases in Gsp (-77 +/- 4%) and CLsp (-65 +/- 7%). We conclude that, compared with Con, RW-sensitized beagle dogs have increased pulmonary vasoconstrictive responses with Hist or RW inhalation.

Pulmonary allergic reactions impair systemic vascular relaxation in ragweed sensitive mice

“…Inflammatory cells produce several pro-inflammatory cytokines, which in turn may have an effect on systemic vasculature. Although extensive evidence of altered smooth muscle reactivity exists in the pulmonary vasculature (Chetta, A. et al, 2007; Horvath, G. et al, 2007; Tazzeo, T. et al, 2003; Theodorou, A. et al, 1997; Wanner, A. et al, 2004; Wilson, J.W. et al, 2003; Witzenrath, M. et al, 2006), little is known about the impact on the systemic vasculature.…”

Bronchial, alveolar, and vascular-induced anaphylaxis and irritant-induced cardiovascular and pulmonary responses.

“…The decreases in BP induced by ragweed challenge in the alveoli appeared to occur proportionately in both systolic and diastolic pressure. Although a decrease in left ventricular function as observed by Chrusch and colleagues (16) cannot be ruled out, it is likely that this decrease was caused by a decrease in heart rate and peripheral and systemic vasodilation together with an increase in pulmonary vascular resistance (26,27). This decrease in heart rate may be mediated by H 3 receptors (16).…”

Local T‐cell activation after segmental allergen challenge in the lungs of allergic dogs

“…[1][2][3][4] Furthermore, the model allows longitudinal studies in individual animals. Our data show activation of local T lymphocytes in the lungs after ragweed deposition in a sub-segment of the lungs of allergic dogs sensitized to ragweed.…”

“…Some of the offspring of allergic beagle dogs develop immunoglobulin E (IgE) antibodies to allergens and immediate-type allergic reactions after exposure to allergens. [1][2][3] The intrapulmonary deposition of ragweed in sensitized allergic dogs results in pulmonary sensitization. The dogs develop bronchial hyper-reactivity, and upon re-exposure of the airways to ragweed, local inflammatory reactions occur that are characterized by histamine release and a rapid increase of neutrophilic granulocytes in the lungs, followed by a local increase of eosinophilic granulocytes and lymphocytes.…”