Ptitsegradskaya, Sergiev Posad, Moscow Province, 141300 Russia, e-mail Vertiprakhov63@mail.ru, alena_fisinina@mail.ru, anna.dolg@mail.ru Received February 2, 2016 A b s t r a c t The pancreas is one of the most important digestive organs releasing the enzymes which hydrolyze all main nutrients to monomers capable of absorption into blood and lymph. <...> The production of hydrolytic enzymes within the cells of digestive glands is submitted to general principles of protein synthesis, and the mechanisms involved have been studied in detail (R.M. Case, 1998). <...> It is not a case, however, for urgent transportation of these enzymes by specialized secretory cells (glandulocytes), a recretory process including the absorption of endogenous secrets from blood stream by glandulocytes with subsequent release of the immutable forms of these secrets within digestive juices. <...> Exocrine secrets of digestive glands, therefore, contain two enzymatic pools: those synthesized de novo and recreted. <...> Analysis of enteropancreatic circulation of pancreatic enzymes (S.S. Rotman et al., 2002) supported the conclusion that under certain conditions only 25-50 % of total circulating pancreatic enzymes are synthesized de novo by the pancreas. <...> Output of digestive enzymes into blood stream depends on the pancreas secretion. <...> In this context the circulation of pancreatic enzymes in human and animals recently has drawn an attention, since these enzymes perform not only digestive but also regulatory function (R. Ramachandran et al., 2008; G.F. Korot’ko, 2011; R. Gružauskas et al., 2015). <...> In the article the experimental data on the activities of pancreatic enzymes in pancreatic juice, duodenal chymus, blood serum, and feces in broiler chicks (Cobb 500, n = 6) are presented. <...> The chicks were operated to collect the pancreatic juice according to unique poultry fistulation method (Ts. <...> Batoev and S.Ts. Batoeva, 1970) allowing the sampling of pancreatic juice during the trial and redirection of the juice into the intestine thereafter without any detrimental effect on health and welfare of poultry. <...> Blood pancreatic enzyme activity and activity in litter were also assayed. <...> The results of our physiological investigation showed that complex-reflex regulatory phase of pancreatic secretion continues during 120 min after feeding with the subsequent transition to neurohumoral phase (mediated by secretion of hormones <...>