• 1 January 1981
    • journal article
    • research article
    • Vol. 105 (3), 212-222
Abstract
In normal rats, the media of small arteries (0.4-0.2 mm diameter) contained intracellular vacuoles, identified ultrastructurally as herniations of 1 smooth muscle cell into another. The hypothesis that intense vasoconstriction would increase the number of such vacuoles was tested. In the media of the saphenous artery and its distal branch, vasoconstriction induced by L-norepinephrine produced many cell-to-cell hernias within 15 min. At 1 day their number was reduced to .apprx. 1/10 of the original number. By 7 days the vessel was almost restored to normal. Triple stimulation over 1 day induced more severe changes in the media. Smooth muscle cells were susceptible to damage in the course of their specific function. Data were discussed in relation to medial changes observed in other instances of arterial spasm.