Proteinase-activated receptor-2 (PAR-2): regulation of salivary and pancreatic exocrine secretion in vivo in rats and mice.
Proteinase-activated receptor-2 (PAR-2) is expressed throughout the gastrointestinal tract including the pancreas, and may be involved in digestive functions. The aim of our study was to evaluate a potential role for PAR-2 in regulating salivary and pancreatic exocrine secretion in vivo. PAR-2-activating peptides (PAR-2-APs), but not selective PAR-1-APs, administered intravenously, increased salivary secretion in the mouse or rat; this effect of the PAR-2-APs was unaffected by atropine, phentolamine, propranolol or indomethacin. Secretion (amylase) by rat parotid gland slices in vitro was also stimulated by PAR-2-APs and trypsin, but not by activation of other PARs. PAR-2-APs, administered to rats in vivo, caused a prompt effect on pancreatic exocrine secretion. PAR-2 mRNA, known to be present in pancreatic tissue, was also detected in parotid tissue. Our results indicate that in addition to a potential role in regulating cardiovascular and respiratory functions, PAR-2 may also play a general role in vivo for the direct regulation of glandular exocrine secretion.
Kawabata
A
A
Department of Pathophysiology & Therapeutics, Faculty of Pharmaceutical Sciences, Kinki University, Higashi-Osaka 577-8502, Japan. kawabata@phar.kindai.ac.jp
Nishikawa
H
H
Kuroda
R
R
Kawai
K
K
Hollenberg
M D
MD
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology; D010306:Parotid Gland / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012469:Salivary Glands / Q000378:metabolism*
D018679:Cholinergic Agonists; D009842:Oligopeptides; D010455:Peptides; D012333:RNA, Messenger; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin; C112356:seryl-leucyl-isoleucyl-glycyl--arginyl-leucinamide; D002217:Carbachol