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Biomedical subjects

B J Undem

Publications and source records attributed to B J Undem.

113 records · Page 7Linked to original sources
PubMed1983

Inhibition by vasoactive intestinal peptide of antigen-induced histamine release from guinea-pig minced lung.

Vasoactive intestinal peptide (VIP) was found to inhibit ovalbumin-induced histamine release from guinea-pig minced lung. Maximum inhibition occurred with a 10-20 min time of preincubation with VIP. Spontaneous histamine release was not altered by VIP. With 2 x 10(-6) M VIP, the dose-response curve to ovalbumin was shifted about 3-fold to the right, but the maximum histamine release was unaltered. Respiratory tract infection with parainfluenza 3 virus did not influence the inhibitory effect of VIP on histamine release.

Animals↗
PubMedDate not supplied

Allergen-induced sensory neuroplasticity in airways.

This study investigates the influence of allergic inflammation in airway sensory innervation. We conclude that allergic inflammation in the guinea pig leads to both an increase in excitability, as manifested by an increase in the mechanical sensitivity of the airway nerve endings, and an induction of substance P production in airway sensory neurons. The data are consistent with the hypothesis that the induction of substance P occurs in fast conducting nodose sensory neurons that were previously devoid of this neuropeptide. Thus, allergen challenge is associated with a phenotypic change in the airway tachykinergic innervation. We also provide evidence that nerve growth factor is a potentially important mediator for these effects, and that it is elevated in the bronchoalveolar lavage of asthmatic subjects.

Allergens↗
PubMedDate not supplied

Neurophysiology of mast cell-nerve interactions in the airways.

The sensitized guinea pig was employed as a model to study the effect of immunological activation of resident mast cells on neuronal activity in the airways. The trachea was isolated with the vagus nerves and vagal sensory ganglia intact. Using conventional electrophysiological recording techniques, we noted that antigenic stimulation led to an increase in the sensitivity of sensory nerve endings located in the airway wall. Moreover, previous work has revealed that antigen challenge potentiates action-potential-driven tachykinin release from afferent fibers in the guinea pig isolated airway. Anatomical and electrophysiological studies indicate that tachykinin-containing sensory fibers directly innervate the local parasympathetic ganglion neurons in the airway. Therefore, antigen-induced increases in the excitability of sensory fibers in the airways can increase parasympathetic tone in the airway by increasing central and peripheral reflex arcs. In addition, we have found that antigen stimulation has direct effects on the excitability of the parasympathetic ganglion neurons. Considered together, the data demonstrate that increased vagal sensory and parasympathetic activity may be a consequence of the allergic reaction in the airways.

Action Potentials↗