Interleukin-5 modulates eosinophil accumulation in allergic guinea pig lung.

Based on its involvement in eosinophil biology, interleukin 5 (IL-5) may play a role in the pulmonary eosinophilia associated with allergic reactions. We have examined that hypothesis using a neutralizing antibody to IL-5 in ovalbumin-sensitized guinea pigs challenged with aerosolized antigen. The extent of eosinophilia has been quantitated in bronchoalveolar lavage (BAL) and by histologic evaluation of lung tissue sections.

Anaphylactic challenge causes eosinophil accumulation in bronchoalveolar lavage fluid of guinea pigs. Modulation by betamethasone, phenidone, indomethacin, WEB 2086, and a novel antiallergy agent, SCH 37224.

Eosinophil infiltration into bronchoalveolar areas of the lung has been assessed in guinea pigs sensitized to ovalbumin (OA) and then challenged with the aerosolized antigen. Cell content, histamine, and guinea pig albumin (GPA) have been measured in bronchoalveolar lavage (BAL) fluid from these animals. Extensive eosinophil accumulation resulted from sensitization followed by OA challenge; monocytes that initially accounted for greater than 80% of the BAL cells remained essentially constant, and neutrophils comprised less than 3% of the population throughout.

The role of a Ca2+/calmodulin dependent plasma membrane Ca2+ channel during concanavalin A activation of MC9 mast cells.

The effects of Con A on free cytoplasmic calcium concentrations in the cloned murine mast cell, MC9, have been measured using the fluorescent calcium indicator quin 2. Con A causes a rapid, small yet sustained rise in free cytosolic calcium (up to 245 nM) followed closely by increased 45calcium uptake and more slowly by histamine release. The increases in 45calcium uptake and histamine release require extracellular calcium.

Antiallergic activity of loratadine, a non-sedating antihistamine.

Loratadine is a new non-sedating antihistamine. The present studies compared loratadine and terfenadine, another non-sedating antihistamine, for their ability to inhibit the bronchial response to histamine and other autacoids which have been implicated as contributing to the symptoms of an allergic reaction. In addition, the two antihistamines were evaluated in models of immunologically mediated allergic reactions.