| Abstract
| - The localization of Ca2+-ATPase activity was ultracytochemically investigated in the rat saphenous artery and nerve terminals innervating the saphenous artery using a lead citrate method devised by Ando et al. (1981). Intense reaction products in the saphenous arterial endothelial cells were observed inside the caveolae and vesicles along the luminal and abluminal sides. In addition, Ca2+-ATPase activity was observed on the external side of the luminal, abluminal and lateral plasma membrane, and the outer membrane of mitochondria. In the smooth muscle cells, intense Ca2+-ATPase activity on the inside of caveolae and vesicles was observed, comparing in intensity with that on the plasma membrane of smooth muscle cells. In the nerve terminals innervating the saphenous artery, Ca2+ -ATPase activity was demonstrated on the plasma membrane of the nerve terminal-Schwann cell interface, the axolemma of unmyelinated axons and the plasma membrane of Schwann cells. It is suggested from the above ultracytochemical results that Ca2+ +-ATPase activity plays an important role in the contraction and relaxation of the saphenous artery, and in the neurotransmitter release.
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