Research in Dr. Bloomquist's laboratory centers on neuroimmune interactions which initiate and perpetuate inflamatory responses, such as edema and smooth muscle contraction, in the lung airways and in the gastrointestinal tract. The long-term goal is to define the specific role of sensory nerves in the development, amplification, dissemination, and maintenance of inflammatory processes important in the etiology of diseases such as asthma, chronic bronchitis, and inflammatory bowel disease. The laboratory was the first to show release of the tachykinin, substance P (SP), by a sulfidopeptide leukotriene (leukotriene D4 , LTD4) in intestinal smooth muscle. More recently we have shown the same interaction in guinea pig airways. Additionally we have demonstrated leukotriene dependent release of SP by another tachykinin, neurokinin A. These studies have thus identified a major role for sulfidopeptide leukotrienes not only as direct smooth muscle agonists but as relay mediators which disseminate the inflammatory reponse from the field of one sensory neuron to those of adjacent sensory neurons, causing a spreading and amplifying local release of sensory neuropeptides which are potent smooth muscle agonists and mediators of edema. Using in situ hybridization techniques, we have found that substance P is more highly expressed in guinea pig than in rat sensory ganglia, in that, in the guinea pig, SP, in addition to being expressed in small nociceptive neurons, is also expressed in many large sensory neurons of other sensory modalities.

We have recently shown expression of precursor forms of SP in vagal tracheal and lung tissues of the guinea pig. Localization of these precursor forms in axons within the peripheral tissues indicates that complete processing of SP from its larger peptide precursors occurs during transport into the lungs and trachea and further suggests a physiologic role for the precursors themselves.

Following sensitization with subcutaneous ovalbumin we have demonstrated marked up regulation of the NK1 class of tachykinin receptors especially in eosinophils associated with the airways.