Rats fed with choline-deficient diets are known as a model of aging and learning impairments due to acetylcholine (ACh) deficiency in the brain which may be associated with a decrease in acetylcholinesterase (AChE; EC 22.214.171.124). To determined the role of AChE in bronchial responsiveness, we examined the contractile response of isolated lung parenchymal strips to ACh in control rats and rats fed with choline-deficient diets. Concentration-response curves to ACh shifted to the lower concentrations and the maximum respose to ACh was greater in rats fed with choline-deficient diets than in control rats (P<0.01). Physostigmine (10-6 M) mimicked effects of choline-deficient diets on the contractile response to ACh. However, concentration response curves to carbachol and 5-hydroxytryptamine did not differ between control rats and rats fed with choline-deficient diets. Choline-deficient diets significantly decreased the AChE activity from homogenates of lung parenchymal tissues (P<0.01). These results suggest that a decrease in AChE activity of lung tissues may relate to airway hyperresponsiveness to ACh.
- acetylcholinesterase deficiency
- bronchial responsiveness
- bronchial smooth muscle
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine