Feeble bronchomotor responses in diabetic rats in association with decreased sensory neuropeptide release

Judith Szilvássy, István Sziklai, Peter Horvath, Maria Szilasi, József Németh, Péter Kovács, Zoltán Szilvássy

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Type I diabetes is associated with a low incidence of asthma. We tested whether a decrease in sensory neuropeptide release is associated with an attenuated bronchocon-strictive response to field stimulation (FS; 100 stimuli, 20 V, 0.1 ms, 20 Hz) in streptozotocin (STZ)-induced diabetes. The organ fluid of the preparations were also tested for substance P, calcitonin gene-related peptide (CGRP), and somatostatin concentrations by RIA. Preparations were from either normal rats or those pretreated with 50 mg/kg STZ iv 8 wk before experiment. A group of STZ-treated animals was supplied with insulin delivery (4 IU/day sc) implants between 4 and 8 wk. A subgroup was formed to study the effect of capsaicin desensitization. The atropine-resistant contraction was attenuated by diabetes without capsaicin-sensitive relaxation response. Exogenous CGRP and substance P potentiated, whereas somatostatin inhibited (1 nM-10 μM) the FS-induced contractions in rings from either group. FS released somatostatin, CGRP, and substance P from 0.17 ± 0.024, 0.15 ± 0.022, and 1.65 ± 0.093 to 0.58 ± 0.032, 0.74 ± 0.122, and 5.34 ± 0.295 in preparations from normal, and from 0.19 ± 0.016, 0.11 ± 0.019, and 0.98 ± 0.116 to 0.22 ± 0.076, 0.34 ± 0.099, and 1.84 ± 0.316 fmol/mg wet wt in preparations from diabetic rats. Insulin supplementation restored neuropeptide release in rings from STZ-treated rats. The results show that the decreased FS-induced contractions occurred with a decrease in sensory neuropeptide release in STZ-diabetic rats.

Original languageEnglish
Pages (from-to)L1023-L1030
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume282
Issue number5 26-5
DOIs
Publication statusPublished - 2002

Keywords

  • Bronchoconstriction
  • Capsaicin
  • Diabetes

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

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