Substance P contributes to rapidly adapting receptor responses to pulmonary venous congestion in rabbits
| Autor: | Ann C. Bonham, C. T. Kappagoda, K Ravi, Jesse P. Joad, Kayleen S. Kott |
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| Rok vydání: | 1996 |
| Předmět: |
Male
medicine.medical_specialty Physiology Left atrium Blood Pressure Receptors Cell Surface Substance P chemistry.chemical_compound Tachykinins Internal medicine Animals Medicine Pulmonary venous congestion Receptor Receptors Tachykinin Dose-Response Relationship Drug business.industry Microcirculation Respiration Anti-Inflammatory Agents Non-Steroidal Biphenyl Compounds Blockade Left atrial pressure Blood pressure medicine.anatomical_structure chemistry Pulmonary Veins Anesthesia Cardiology Rabbits Pulmonary congestion business Research Article |
| Zdroj: | The Journal of Physiology. 493:229-238 |
| ISSN: | 0022-3751 |
| DOI: | 10.1113/jphysiol.1996.sp021378 |
| Popis: | 1. This study tested the hypothesis that substance P stimulates rapidly adapting receptors (RARs), contributes to the increase in RAR activity produced by mild pulmonary congestion, and evokes an augmented response from RARs when combined with near-threshold levels of pulmonary congestion. 2. RAR activity, peak tracheal pressure, arterial blood pressure and left atrial pressure were measured in paralysed, anaesthetized and ventilated rabbits. Substance P was given i.v. in one-half log incremental doses to a maximum of 3 micrograms kg-1. Mild pulmonary congestion was produced by inflating a balloon in the left atrium to increase left atrial pressure by 5 mmHg. Near-threshold levels of pulmonary congestion were produced by increasing left atrial pressure by 2 mmHg. 3. Substance P produced dose-dependent increases in RAR activity. The highest dose given increased the activity from 1.3 +/- 0.5 to 11.0 +/- 3.1 impulses bin-1. Increases in left atrial pressure of 5 mmHg increased RAR activity from 3.8 +/- 1.4 to 14.7 +/- 3.9 impulses bin-1. Blockade of NK1 receptors with CP 96345 significantly attenuated RAR responses to substance P and to mild pulmonary congestion. 4. Doses of substance P, which alone had no effect, stimulated the RARs when delivered during near-threshold levels of pulmonary congestion. 5. The findings suggest that substance P augments the stimulatory effect of mild pulmonary congestion on RAR activity, most probably by enhancing hydraulically induced microvascular leak. |
| Databáze: | OpenAIRE |
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