THE PARTICIPATION OF CERTITUDE, ANALOGOUS TO CHOLECYSTOKININ-PEPTIDE, IN THE REGULATORY MECHANISM OF SALIVARY SECRETION IN MICE

1992 Fiscal Year Final Research Report Summary

• Project/Area Number: 03670870
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Functional basic dentistry
• Research Institution: IWATE MEDICAL UNIVERSITY
• Principal Investigator: ITO Tadanobu IWATE MEDICAL UNIVERSITY, SCHOOL OF DENTISTRY, DENTAL PHARMACOLOGY, PROFESSOR, 歯学部・歯科薬理学, 教授 (00048274)
• Co-Investigator(Kenkyū-buntansha): SAITO Hiroko IWATE MEDICAL UNIVERSITY, SCHOOL OF DENTISTRY, DENTAL PHARMACOLOGY, ASSISTANT, 歯学部・歯科薬理学, 助手 (30124902) ; MURAI Shigeo IWATE MEDIDAL UNIVERSITY, SCHOOL OF DENTISTRY, DENTAL PHARMACOLOGY, ASSOCIATE PR, 歯学部・歯科薬理学, 助教授 (70005057)
• Project Period (FY): 1991 – 1992
• Keywords: Ceruletide / CCK-8 / Peptide / Salivary gland / Salivation / Regulation of salivary secretion / Autonomic agents / Mouse

Research Abstract

It is suggested that cholechystokinin-octapeptide(CCK-8), related to the gut hormone, is widely distributed in mammalian brains and may play a role as neurotramsmitters and/or neuromodulators. However, the physiological effects of CCK-8 are not entirely clear. It is reported that ceruletide (CER) analogous to CCK-8 produces an inhibition of locomotor activity in mice, and an inhibition of salivary flow in human. In this study, we explored whether CER (0.4-40 mug/kg, S.C.) has an influence on the response to the salivary secretion in mice. this was investigated using autonomic drugs, comparing the results to that of CCK-8 (5-500mu/kg, S.C.). In this experimental manner using the modified Richter's method, the CER stimulated the salivary secretion in mice treated with beta-adrenergic, especially beta_1-receptors acting drug dobutamine(10mg/kg, S.C.), but it did not stimulate in mice treated with *-adrenergic (phenylephrine 5 mg/kg, S.C. and clonidine 5 mg/kg, S.C.) and cholinergic (pilocarpine 0.8mg/kg, S.C.) drugs. On the other hand, the CCK-8 stimulated the salivary secretion in mice treated with cholinergic agent (pilocarpine 0.8mg/kg, S.C.), but it did not stimulate in mice treated with *-adrenergic (phenylephrine 5mg/kg, S.C. and clonidine 5mg/kg, S.C.) and beta-adrenergic (dobutamine 10 mg/kg, S.C. and salubutamide 40 mg/kg, S.C.) drugs. These results suggest that for the response to the salivary secretion in mice CER has pharmacological properties different from those of CCK-8, as well as different effects between CER and CCK-8 on the locomotor activities of mice. Furthermore, for the participation of the GABAergic, dopaminergic and serotonergic nervous systems in the response of CER to the salivary secretion of mice, it remains a problem to be resolved.