Airway responses to capsaicin in guinea pigs: role of NK-1 and NK-2 neurokinin receptors.

The role of NK-1 and NK-2 receptors on the pulmonary response to capsaicin in guinea pigs was evaluated using intravenous infusion of selective nonpeptide antagonists of NK 1 (CP 96345, 300 nmol/kg, and SR 140333, 300 nmol/kg) and NK-2 (SR 48968, 100 nmol/kg) neurokinin receptors. Maximal values of pulmonary dynamic elastance (Edyn) and pulmonary resistance (RL) after capsaicin infusion were significantly lower in the presence of SR 48968 (p < .005). Morphometric analysis of lungs obtained by quick-freezing showed significant attenuation of airway contraction and peribronchiolar edema formation in the presence of NK-2 antagonist (p < .001). When compared to guinea pigs that received only capsaicin, animals that received SR 140333 or CP 96345 showed lower values of Edyn, RL, airway contraction, and peribronchiolar edema, but only the difference in Edyn values was significant. The combination of NK-1 and NK-2 antagonists was not more effective than NK-2 antagonist alone in attenuating capsaicin effects. The results suggest that airway effects of capsaicin are mainly mediated by activation of NK-2 receptors although NK-1 receptors may also play a role.

Capsaicin-induced release of VIP-like immunoreactivity: modulation by enzyme inhibitors.

Vasoactive intestinal peptide (VIP) is a potent bronchial smooth muscle relaxant. In the present study we measured the release of VIP-like immunoreactivity (VIP-LI) after tracheal infusion of capsaicin, histamine, and methacholine in isolated guinea pig lungs superfused through the trachea. We also studied if inhibition of VIP enzymatic cleavage using a combination of an inhibitor of neutral endopeptidase [thiorphan (Thio)] and an inhibitor of serine proteases [soybean trypsin inhibitor (STI)] influenced the airway effects of capsaicin. Infusion of capsaicin resulted in a significant increase in VIP-LI in the perfusate (12.32 +/- 4.80 to 33.52 +/- 8.46 fmol/5 min fraction; P < 0.001). There was no increase in VIP-LI after infusion of methacholine or histamine. Maximal changes in airway opening pressure (Pao) observed 0-10 min after tracheal infusion of capsaicin were significantly greater in the Thio group than the control group and the groups of lungs that received STI or STI + Thio (P < 0.005). In addition, recovery of VIP-LI in the superfusate after infusion of capsaicin was significantly greater in the group of lungs that was superfused with Thio + STI compared with STI, Thio, and control groups. Our results suggest that a bronchodilator peptide with the profile of enzymatic cleavage of VIP also modulates capsaicin effects, since the increase in Pao in the presence of Thio + STI was significantly lower than Thio alone.

Neurokinin depletion attenuates pulmonary changes induced by antigen challenge in sensitized guinea pigs.

The role of neurokinins in the acute pulmonary response to antigen was studied in guinea pigs that received ovalbumin (50 mg/kg ip) on days 1 and 3 and capsaicin (50 mg/kg sc) on day 21 (OAC); ovalbumin on days 1 and 3 (OA1); capsaicin on day 1 and OA on days 8 and 10 (COA); and ovalbumin on days 8 and 10 (OA2). On day 28, guinea pigs were submitted to ovalbumin aerosol challenge. Maximal values of pulmonary dynamic elastance (Edyn) and pulmonary resistance (RL) were significantly lower in OAC and COA groups compared with OA1 and OA2 groups (P < 0.001). There was no difference between maximal Edyn and RL values obtained in OAC and COA groups. Morphometric analysis of lungs showed significantly (P < 0.05) lower values of contraction index of airways, peribronchial edema, and alveoli over inflation in guinea pigs that received capsaicin compared with intact guinea pigs. Capsaicin treatment did not influence the formation of specific IgG1 anaphylactic antibodies. We conclude that neurokinin depletion results in a decrease in the pulmonary mechanical and inflammatory responses to antigen challenge in sensitized guinea pigs. These effects are observed when capsaicin is given either before or after sensitization.

[Two cases of severe cutaneous vasculitis with thrombocytopenia associated with hepatic cirrhosis: autoimmune and infective-inflammatory component with endothelial lesion and restrictive pulmonary pattern in one case]. / Dois casos de vasculite cutânea grave com plaquetopenia associada à cirrose hepática: componente autoimune e infecto-inflamatório com lesão endotelial e padrão restritivo pulmonar em um caso.

Two clinical cases of female patients with hepatic cirrhosis and autoimmune multisystemic involvement with infectious intercurrent are reported. Case 1 presented infective endocarditis and erysipelas on the left thigh. In the course of the clinical picture a cutaneous vasculitis developed in the same place together with autoimmune thrombocytopenia, leukopenia and pulmonary restrictive picture with inflammatory pattern. There are also elevate immune complexes and complement consumption. Case 2 presented erysipelas on the left thigh cutaneous vasculitis and complement consumption. In Case 1 the infective endocarditis was treated with antibiotic therapy during 4 weeks followed by 1 mg/kg corticoid (Prednisone) with thrombocytopenia and leukopenia reversion. Case 2 presented an improvement with antibiotic only. The relation between chronic liver diseases and systemic autoimmune phenomena is commented, special attention being paid to the cutaneous, hematological and pulmonary affection.

Massive infestation by Ascaris lumbricoides of the biliary tract: report of a successfully treated case.

This is a report of a 25 years old black woman from the city of São Paulo, Brazil, who developed acute obstructive cholangitis of Ascaris lumbricoides with septicemia and multiple hepatic abscesses. The patient had sickle cell trait and normal delivery 3 months ago. Massive infestation of the biliary tract by Ascaris lumbricoides was diagnosed by abdominal ultrasonography and endoscopic retrograde cholangiography. Sixty worms were removed from the common bile duct and hepatic abscesses were drained by surgery. The infectious process was polymicrobial. The patient's recovery was complete after a long evolution with a wide spectrum antibiotic therapy. New surgeries were needed to remove residual worms in the biliary tract. The diagnostic methods, clinical-biochemical features and also the clinical and surgical management are presented. The biliary ascariasis pathophysiology is commented.

[Lethal pulmonary involvement in neurofibromatosis]. / Comprometimento pulmonar letal na neurofibromatose.

A unusual case of a 61-year-old man who presented dyspnea and cough associated to skin and subcutaneous lesions typical of neurofibromatosis type 1 is reported. Chest roentgenograms and CT-scan showed emphysematous bullae. The patient underwent drainage of the greatest bulla, but death eventually ensured as a consequence of upper digestive bleeding. It can be expected that with the longer survival of neurofibromatosis patients with respiratory troubles, that are generally considered unusual will be recognized more frequently.