The Role of Nitric Oxide in the Exocrine Pancreatic Function in Chicken

Аннотация

The universal cell mediator nitric oxide (NO) mediating the physiological effects via so-called NO donor compounds prolonging its life time. The concentration of NO metabolites in the pancreatic juice of chicken was determined by the enzymatic sensor. It was found that pancreatic juice from starved birds contains nitrate and no other nitro- or nitroso compounds. After feeding, the NO donors appear in pancreatic juice in concentrations of a few tens of μM. These compounds were present in pancreatic juice for several hours after feeding. It is possible that NO donors promote relaxation of the smooth muscles in the walls of pancreatic ducts. Concentration of NO donors in blood serum also increased 2.5–3.0-fold after feeding and remained high during a few subsequent hours. The preliminary subcutaneous administration of atropine to the birds prevent this increase with no effects on the initial concentrations of NO donors in serum. This suggests that the increase is associated with cholinergic stimulation and, therefore, with the activity of the parasympathetic nervous system. The concentration of trypsin in serum also increased after feeding, and atropine also prevents this increase. It is known that serum trypsin acts as a regulator of pancreatic function. Intravenous administration of trypsin led to an insignificant increase of tryptic activity in serum but induced the increase of NO donor concentration twofold. Apparently, nitric oxide, represented by these compounds, can act as a humoral factor in the regulation of pancreatic function in pancreatic juice and possibly in the blood.