Melatonin, the major hormone secreted by the pineal gland, is a key modulator of seasonal and circadian biorhythms. The synthesis and secretion of melatonin is controlled by a circadian clock in the hypothalamus and is synchronized by the light-dark cycle. NovoLytiX provides the gold standard in immunological determination of melatonin with ELISA and RIA.
The production of melatonin is inhibited by daylight and occurs during darkness. Thus, melatonin levels are very low during day and rise in the evening. Melatonin is a conservative Molecule and as such is ubiquitous. Not only has it been described in humans and animals, but also in plants and even in microorganisms.
In humans circadian melatonin profiles in body fluids (saliva, serum, plasma) provides an excellent marker for the setting of the endogenous clock. Night-time levels peak at around 3:00 am (acrophase) in most healthy individuals. As a general modulator of human and other vertebrate biorhythm, melatonin is involved in the timing of functions such as sleep, mood, reproduction and immune system activities.
Both, the intra-individual Melatonin onset and acrophase are very stable. Therefore, it will be sufficient to measure the onset of melatonin production, only, once a whole melatonin profile has been established. The onset of melatonin production may be defined as the DLMO (Dim Light Melatonin Onset) for monitoring shifts of the profile.
NovoLytiX offers most sensitive Immunoassays to measure any kind of biological sample by ELISA technique. An accurate ELISA to determine the main metabolite in urine, 6-sulfatoxymelatonin, is also available.
The principal metabolite of melatonin is 6-sulfatoxymelatonin. The particular advantage of measuring 6-sulfatoxy-melatonin is the ability to assess pineal function by urine sampling, since urine contains only traces (approx. 1%) of non-metabolized melatonin. The measurement of 6-sulfatoxymelatonin in urine provides a non-invasive, integrated parameter by which circadian rhythms can be assessed over a period of time.
NovoLytiX has an variety of products to determine melatonin levels in order to find individual shifts in sleep-wake cycles.
Human vasopressin, also called antidiuretic hormone (ADH), is a hormone that has two primary functions. First, it increases the amount of solute-free water reabsorbed back into the circulation from the filtrate in the kidney tubules of the nephrons. Second, AVP constricts arterioles, which increases peripheral vascular resistance and raises arterial blood pressure. Vasopressin regulates the tonicity of body fluids, in response to hypertonicity is release into the circulation and causes the kidneys to reabsorb solute-free water and return it to the circulation from the tubules of the nephron, thus returning the tonicity of the body fluids toward normal. An incidental consequence of this renal reabsorption of water is concentrated urine and reduced urine volume. AVP released in high concentrations may also raise blood pressure by inducing moderate vasoconstriction.
NovoLytiX has an variety of products to determine vasopressin levels in order to find individual shifts in blood, plasma or urine.
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