Biomaterial Database

Differential effects of manganese and magnesium on two types of slowly adapting cutaneous mechanoreceptor afferent units in frogs. 1986

Y Yamashita, and H Ogawa, and K Taniguchi

While perfusing a frog leg with various solutions, the mechanical responsiveness of slowly adapting (SA) cutaneous mechanoreceptor afferent units innervating the plantar surface of the hindfoot was examined. Perfusion with normal Ringer solutions enhanced the mechanical responsiveness of two types of the SA units, irregularly discharging Frog type I units and regularly discharging Frog type II units, in comparison with that by normal blood supply. On the other hand, when the perfusion was made with Ringer solutions containing Ca blockers, i.e., Mn and Mg, the response magnitudes of both units were reversibly and dose-dependently decreased. Ringer solutions containing 3 mM Mn or 20 mM Mg almost abolished the maintained responses of the Frog type I units to ramp stimulation of the skin, while Ringer solutions of 10 mM Mn significantly decreased those of the Frog type II units. It is suggested that Ca in the medium is a prerequisite to mechanoelectric transduction and the spike generation process at the terminal regions of these slowly adapting cutaneous mechanoreceptor afferent units. Findings that the Frog type I units were quantitatively more sensitive to these Ca blockers than the Frog type II units suggest that an additional process of higher Ca-sensitivity, e.g., chemical synaptic transmission, may be involved on the way from mechanoelectric transduction to the spike generation of the Frog type I units.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008297	Male		Males
D008345	Manganese	A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
D008465	Mechanoreceptors	Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.	Golgi Tendon Organ,Golgi Tendon Organs,Krause's End Bulb,Krause's End Bulbs,Mechanoreceptor,Mechanoreceptor Cell,Meissner's Corpuscle,Neurotendinous Spindle,Neurotendinous Spindles,Receptors, Stretch,Ruffini's Corpuscle,Ruffini's Corpuscles,Stretch Receptor,Stretch Receptors,Mechanoreceptor Cells,Bulb, Krause's End,Bulbs, Krause's End,Cell, Mechanoreceptor,Cells, Mechanoreceptor,Corpuscle, Meissner's,Corpuscle, Ruffini's,Corpuscles, Ruffini's,End Bulb, Krause's,End Bulbs, Krause's,Krause End Bulb,Krause End Bulbs,Krauses End Bulb,Krauses End Bulbs,Meissner Corpuscle,Meissners Corpuscle,Organ, Golgi Tendon,Organs, Golgi Tendon,Receptor, Stretch,Ruffini Corpuscle,Ruffini Corpuscles,Ruffinis Corpuscle,Ruffinis Corpuscles,Spindle, Neurotendinous,Spindles, Neurotendinous,Tendon Organ, Golgi,Tendon Organs, Golgi
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
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
D004553	Electric Conductivity	The ability of a substrate to allow the passage of ELECTRONS.	Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D005260	Female		Females
D006614	Hindlimb	Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)	Hindlimbs