Effect of ipratropium bromide abrupt withdrawal, after chronic treatment, in contractile response of isolated rat tracheas

Autor: Moraes, Isabelle Maciel de
Přispěvatelé: Capaz , Francisco Ruy
Jazyk: portugalština
Rok vydání: 2004
Předmět:
Zdroj: Repositório Institucional da Universidade Federal do Ceará (UFC)
Universidade Federal do Ceará (UFC)
instacron:UFC
Popis: In order to evaluate ipratropium bromide (IB) abrupt withdrawal effects after chronic treatment in isolated rat tracheas, male rats weighing 200-250g were placed in plastic chambers and submitted to inhalation of IB (600µM) during seven minutes. This protocol was repeated each four hours during 14 days. Two inhalation chambers were used, one with experimental group (IB inhalation) and the other with control group (CONT, saline). Another group was ovalbumin (OVA) actively sensitized (SZ) and submitted to the same protocol of inhalation. These animals were challenged 24hours before the beginning of the experiments by antigen inhalation (OVA: 1mg/ml; 5mg/ml; 15/15 minutes) (group DESF). At the end of IB treatment period the animals were killed and 0, 4, 8, 12 hours after the last inhalation the tracheas were quickly removed. After dissection the tracheal rings were transferred to a 8 ml organ bath containing Krebs-Henseleit solution mMol/l: NaCl 113.0; KCl 4.7; CaCl2.2H2O 1.2; KH2PO4 1.2; MgSO4.7H2O 1.2; NaHCO3 25.0; Glucose 11.0; 37º C; 95%O2/5%CO2). Concentration-effect curves (CEC) were constructed to carbachol (Cch), serotonin (5-HT), potassium (KCl), calcium (CaCl2) and electric stimulus. CEC to Cch obtained with tracheas isolated from rats submitted to only one IB inhalation showed shift to the right with an increase in the EC50 values [EC50x10-7M: CONT=1.78(1.32-2.32); IB=14.6(2.05-58.1) p
Databáze: OpenAIRE