| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2001: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
The cell bodies of the sympathetic preganglionic nerve are found in the intermediolateral nucleus of the rat spinal cord. Sympathetic preganglionic nerves are known as a major passage of the autonomic nerve sysrem.
We have already reported that 20 % of the cell bodies of the rat sympathetic preganglionic nerve fibers have monoamine oxidase B(Mao-B) and the others have neither monoamine oxidase A (Mao-A) nor Mao-B. In 2001, we reported that dopaminergic nerve endings made contact with the cell bodies of Mao-B-positive sympathetic preganglionic neurons, but not with those of the Mao-B-negative neurons. Our result suggests that Mao-B in the sympathetic perganglionic nerve fiber are involved in the degradation of dopamine released from the dopaminergic nerve endings. In 2002, we studied about noradrenergic nerve terminals in the intermediolateral nucleus. Unexpectedly, the noradrenergic nerve endings made contact with the cell bodies of the Mao-B negative neurons, but not with positive ones. Thus, noradrenergic efferent fibers originated from brainstem were unlikely a passage to sympathetic preganglionic neurons. Besides, in the peripheral nervous system, we found Mao-B in mitochondria of mast cells, fibroblast, endothelial cell and Schwann cell, in the tongue connective tissue. Mast cells are known to synthesize histamine and release it. We also founbed histamine transmethylase in the epithelium of the tongue. The histamine transmethylase methylates histamine and then methyl histamine is thought to be degragated with Mao B. Taken together, it is suggested that the Mao B of mast cells in the tongue is involved in the metabolism of endogenous histamine.,
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