Local administration of 2% trimecaine affects the content of fucosylated glycoconjugates in goblet cells in rabbit tracheal epithelium

Abstract

The proportion of fucosylated glycoconjugate-containing rabbit tracheal goblet cells after intratracheal application of trimecaine was studied to evaluate its possible unfavourable effects. This lapine model is comparable with diagnostic findings in humans because airway epithelia in humans and rabbits are similar; tracheal epithelium is also practically identical to bronchial epithelium in both species. Local trimecaine anaesthesia caused a proportional decrease in percentage of the tracheal goblet cells containing both alpha(1-2)- and alpha(1-6)-, alpha(1-3)- and alpha(1-4)-fucosylated glycoconjugates as revealed 10 min postexposure using lectin histochemistry. In previous studies, only mild ultrastructural damage to the airway's epithelium was revealed, but a conspicuous decrease in sialylated glycoconjugate-containing tracheal goblet cells and the dominance of acidic sulphated glycoconjugates were observed as after-effects of the same treatment. Glycoconjugate changes can influence the inner environment of airways (e.g. viscoelastic properties of the airways' mucus and mucosal barrier functions) and thus the patient's defence barriers in airways may be weakened. Concurrently, the histochemical properties of goblet cells can be altered in bronchoscopic specimens. Since trimecaine is widely used as local anaesthesia in airways in bronchoscopy, it is necessary to heed these aforementioned effects.

Figure 1

Goblet cells containing mucous granules with both acidic (violet; Alcian Blue-positive – black arrow) and neutral (magenta; PAS-positive – grey arrow) glycoconjugates in a control rabbit.

Figure 2

Goblet cell (black arrow) containing ULE-I-positive mucous granules 10 min after administration of trimecaine. Grey arrows indicate ULE-I-positive surfaces of some goblet cells.

Figure 3

Goblet cell (black arrow) containing ULE-I-negative mucous granules 10 min after administration of trimecaine. Grey arrows indicate ULE-I-positive surfaces of some goblet cells.

Figure 4

Goblet cell (black arrow) releasing its AAL-positive mucous granules 10 min after administration of trimecaine. Note the intense staining of the ciliary border.

Figure 5

Proportions of goblet cells containing AAL-positive granules only, ULE-I-positive granules only, and both lectin-positive granules. Venn's diagram. Sum = the sum of percentages of goblet cells detected individually; sim = the percentage of goblet cells detected simultaneously. Means ± SD; *Values differ (α = 0.05) from controls.