Biomaterial Database

Taste responses to electrolytes in the frog glossopharyngeal nerve: enhancement by Ni2+ ions. 1990

Y Kitada

Okayama University Dental School, Japan.

In studies of whole-nerve recordings from the frog glossopharyngeal nerve, Kashiwagura et al. reported that Ni2+ enhances responses to MgCl2 and NaCl and that such enhanced responses are suppressed by Ca2+. In the present study, it was found that the responses to electrolytes of single water fibers of the frog glossopharyngeal nerve are enhanced by Ni2+. Ni2+ enhances the responses to MgCl2, NaCl, and CaCl2. The enhancement of the response to CaCl2 suggests that inhibition of the enhanced response by Ca2+ is not caused by the relationship between Ca2+ and Ni2+ ions on the receptor membrane. Kitada reported that, in the absence of Ni2+, Ca2+ competitively inhibits the responses to Na+ and Mg2+; and Kitada and Shimada reported that the response to Ca2+ is competitively inhibited by Na+ and Mg2+. The possibility is discussed that inhibition of the enhanced response by Ca2+ is due to competition between Ca2+ and Na+ and between Ca2+ and Mg2+ for multiple specific receptor sites.

UI	MeSH Term	Description	Entries
D007477	Ions	An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
D009532	Nickel	A trace element with the atomic symbol Ni, atomic number 28, and atomic weight 58.69. It is a cofactor of the enzyme UREASE.
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D011898	Ranidae	The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.	Frogs, True,Rana,Frog, True,True Frog,True Frogs
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004573	Electrolytes	Substances that dissociate into two or more ions, to some extent, in water. Solutions of electrolytes thus conduct an electric current and can be decomposed by it (ELECTROLYSIS). (Grant & Hackh's Chemical Dictionary, 5th ed)	Electrolyte
D005930	Glossopharyngeal Nerve	The 9th cranial nerve. The glossopharyngeal nerve is a mixed motor and sensory nerve; it conveys somatic and autonomic efferents as well as general, special, and visceral afferents. Among the connections are motor fibers to the stylopharyngeus muscle, parasympathetic fibers to the parotid glands, general and taste afferents from the posterior third of the tongue, the nasopharynx, and the palate, and afferents from baroreceptors and CHEMORECEPTOR CELLS of the carotid sinus.	Cranial Nerve IX,Ninth Cranial Nerve,Cranial Nerve IXs,Cranial Nerve, Ninth,Cranial Nerves, Ninth,Glossopharyngeal Nerves,Nerve, Glossopharyngeal,Nerve, Ninth Cranial,Nerves, Glossopharyngeal,Nerves, Ninth Cranial,Ninth Cranial Nerves
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23