At the Tone, Your Body-Clock Time Will Be ...
At the Tone, Your Body-Clock Time Will Be ...
June 28, 2001 -- Researchers at the University of Pennsylvania have identified a possible way that the body's master "clock" tells other timekeepers throughout the body when to synchronize their watches. The finding suggests possible new strategies for treating high blood pressure, jet lag, and other conditions linked to disturbances in the body's normal daily rhythms.
The master clock, which helps control the 24-hour sleep-wake cycle known as the circadian rhythm, is located deep in the brain. But researchers previously discovered that other organs such as the heart, liver and kidneys contain their own so-called peripheral clocks that tick away in a coordinated rhythm related to time signals from the master clock, which is itself controlled by several key genes.
"Not only does this clock mechanism occur in the brain, but all of these genes are expressed in a number of other tissues throughout the body, so we know that there are a number of other clock-like structures throughout the body that require input from the central clock, but are probably very important for the local control of daily variations in metabolism," explains Steven M. Reppert, MD professor and chair in the department of neurobiology at the University of Massachusetts School of Medicine in Worcester.
Heart and blood vessel researchers also know that blood pressure is subject to daily fluctuations linked to the circadian rhythm, and that heart attacks, sudden cardiac death, and strokes occur more frequently at specific times of the cycle.
A key piece of this biological puzzle must still be found, though, to show how circadian regulation of blood pressure occurs, and how the other clocks manage to keep time with the master clock. Now, Garret FitzGerald, MD and colleagues at Penn, reporting in the June 29 issue of the journal Cell, think they may have found that missing piece of the puzzle.
In a study using mice, the authors found that levels of a protein labeled MOP4 maintain a 28-hour cycle in the hearts and major blood vessels of animals that were kept in the dark (to remove all time cues), implicating the protein as an important timekeeper in blood vessels.
At the Tone, Your Body-Clock Time Will Be ...
June 28, 2001 -- Researchers at the University of Pennsylvania have identified a possible way that the body's master "clock" tells other timekeepers throughout the body when to synchronize their watches. The finding suggests possible new strategies for treating high blood pressure, jet lag, and other conditions linked to disturbances in the body's normal daily rhythms.
The master clock, which helps control the 24-hour sleep-wake cycle known as the circadian rhythm, is located deep in the brain. But researchers previously discovered that other organs such as the heart, liver and kidneys contain their own so-called peripheral clocks that tick away in a coordinated rhythm related to time signals from the master clock, which is itself controlled by several key genes.
"Not only does this clock mechanism occur in the brain, but all of these genes are expressed in a number of other tissues throughout the body, so we know that there are a number of other clock-like structures throughout the body that require input from the central clock, but are probably very important for the local control of daily variations in metabolism," explains Steven M. Reppert, MD professor and chair in the department of neurobiology at the University of Massachusetts School of Medicine in Worcester.
Heart and blood vessel researchers also know that blood pressure is subject to daily fluctuations linked to the circadian rhythm, and that heart attacks, sudden cardiac death, and strokes occur more frequently at specific times of the cycle.
A key piece of this biological puzzle must still be found, though, to show how circadian regulation of blood pressure occurs, and how the other clocks manage to keep time with the master clock. Now, Garret FitzGerald, MD and colleagues at Penn, reporting in the June 29 issue of the journal Cell, think they may have found that missing piece of the puzzle.
In a study using mice, the authors found that levels of a protein labeled MOP4 maintain a 28-hour cycle in the hearts and major blood vessels of animals that were kept in the dark (to remove all time cues), implicating the protein as an important timekeeper in blood vessels.
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