The research in my laboratory is directed towards the investigation of gastrointestinal functions of peptides such as substance P, neurokinins and endothelins; studies include the investigation of the control of release of these peptides, and the effects these peptides have on gastric and pancreatic endocrine secretion, gastric acid secretion, gastrointestinal motility and neurotransmitter release in the peripheral and enteric nervous system. The localization, distribution and classification of these peptide receptors are also studied using autoradiographic and radioligand binding techniques. The cholinergic and purinergic mechanism in the gastrointestinal tract are also studied. These include investigation of the actions of adenosine and its analogues, the regulation of the acetylcholine release and synthesis, as well as the distribution and localization of cholinergic and purinergic receptors. The peptidergic, cholinergic and purinergic mechanisms under pathophysio-logical states, such as diabetes and gastrointestinal ulcerative formations, are also studied.

Neurotrophic factors in the gastrointestinal tract and the urinary bladder (neurotrophins; receptor identification and localization; biological actions)

Mechanisms in neurodegenerative diseases (Parkinsonism; dyskinesia; regulatory peptides)

Kwok, Y.N. and B. Collier. The synthesis of acetylcholine from acetate in a sympathetic ganglion. J. Neurochem. 39:16-26, 1982.

Kwok, Y.N., C.H.S. McIntosh, R.A. Pederson, and J.C. Brown. Effect of substance P on somatostatin release from the isolated perfused rat stomach. Gastroenterology, 88:90-95, 1985.

Kwok, Y.N., A.M.J.Buchan, C.H.S. McIntosh and J.C. Brown. A study of Substance P in gastric tissues: receptor localization, effect on somatostatin release and its relationship to neurokinins. Can. J. Physiol. Pharmacol., Symp. on GI Hormones: pp. 174, July 1986.

Kwok, Y.N. Effect of Substance P and neurokinins on the endocrine secretion of the pancreas and stomach. In Substance P and Neurokinins (Eds. Henry, J., Conture, R., Cuello, A.C., Pelletier, G., Quirion, R. and Regoli, D.), Springer-Verlag, New York, pp. 214-216, 1987.

Kwok, Y.N., C.B. Verchere, C.H.S. McIntosh and J.C. Brown. Effect of galanin on endocrine secretions from the isolated perfused rat stomach and pancreas. Eur. J. Pharmacol. 145:49-54, 1988.

Kwok, Y.N., C.H.S. McIntosh, H. Sy and J.C. Brown. Inhibitory effect of tachykinins and neurokinin on somatostatin release from the isolated perfused rat stomach. J. Pharmacol. Exp. Ther. 246:726-731, 1988.

Buchan, A.M.J., M.D. MacLeod, R.M. Meloche and Y.N. Kwok. Muscarinic regulation of somatostatin release from primary cultures of human antral epithelial cells. Pharmacology 44: 33-40, 1992.

Kwok, Y.N., C. McIntosh, and J.C. Brown. Augmentation of release of gastric somatostatin-like immunoreactivity by adenosine, adenosine triphosphate and their analogs. J. Pharmacol. Exp. Ther. 255: 781-788, 1990.

Kwok, Y.N. and C.H.S. McIntosh. Release of substance P-like immunoreactivity from the vascularly perfused rat stomach. Europ. J. Pharmacol. 180: 201-207, 1990.

Kwok, Y.N. Purinergic control of release of somatostatin in the rat stomach. Pathophysiology 1 (Suppl.) 218, 1994.

Fujimiya, M. and Kwok, Y.N. Effect of capsaicin on release of substance P-like immunoreactivity from the vascularly perfused rat duodenum. Dig. Dis. Sci. 40:96-99, 1995.

Wakabayashi, Y., T. Maeda and Y.N. Kwok. Increase aof p75 immunoreactivity in rat urinary bladder following inflammation. NeuroReport 7: 1141-1144, 1996.

Yip L & Kwok Y.N. Role of adenosine A2A receptor in the regulation of gastric somatostatin release. J. Pharmacol. Exp. Ther. 309:804-815, 2004.

Yip L, Leung HCH & Kwok Y.N. Role of adenosine A1 receptor in the regulation of gastrin release. J. Pharmacol. Exp. Ther. 310:477-487, 2004. (Figure chosen for cover of Journal)

Yip L, Leung HCH & Kwok Y.N. Effect of omeprazole on gastric adenosine A1 and A2A receptor gene expression and function. J. Pharmacol. Exp. Ther. 311:180-189, 2004.