Characterisation of chloride currents in the jejunum and colon of pigs

Chloride secretion in the intestines of pigs of different age (32 days and 4 months) was examined using the Ussing chamber technique. After stimulating chloride secretion by carbachol and forskolin, alternative chloride channels and finally Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) channels were blocked. While basal short-circuit currents (I_sc) were higher in the jejunum than in the colon of the piglets of 32 days, it was inverse for the 4-month-old fatteners. In the jejunum responses to stimulation and final levels of I_sc were higher in the piglets than in the fatteners. The decrease in I_sc after blocking CFTR channels was smaller in the fatteners than in the piglets in both intestinal segments. In conclusion, 32-day-old piglets show a higher basal chloride secretion as well as a higher response to stimulation in the jejunum than 4-month-old pigs.