Study description:~Melatonin, a natural hormone of the pineal gland exclusively released during the dark phase, exhibits vasodilatatory effects in distal skin regions and reduces core body temperature. This study investigates whether exogenous melatonin (5mg p.o. at 2p.m.) in the afternoon, when no endogenous melatonin is secreted, increases not only distal skin blood flow, but also choroidal blood flow and changes oxygen consumption. Two subject groups were studied, women with vasospastic syndrome (VS) and controls. The main hypothesis is: melatonin normalizes distal vasoconstriction in VS.~Further questions will also be answered:~Does melatonin affect basal metabolic rate, increase choroidal blood flow and reduce the vasospastic syndrome (VS)?~Do women with VS exhibit:~a different basal metabolic rate~a reduced choroidal blood flow~a reduced increase of oxygen consumption after intake of ice-water~a different oxygen consumption after melatonin intake~a different choroidal blood flow after melatonin intake~a different oxygen consumption after melatonin intake and after intake of ice-water....?
Does melatonin affect basal metabolic rate, increase choroidal blood flow and reduce the vasospastic syndrome (VS)?~The main questions are:~Do women with VS exhibit...~a different basal metabolic rate~a reduced choroidal blood flow~a reduced increase of oxygen consumption after intake of ice-water~a different oxygen consumption after melatonin intake~a different choroidal blood flow after melatonin intake~a different oxygen consumption after melatonin intake and after intake of ice-water….?