On Fri, 17 Nov 1995 skim at alliant.snu.ac.kr wrote:
>Seong-hun wrote:
>>> 1. You mentioned taking melatonin at certain times of day can either phase-
> advance or phase-delay one's own melatonin production. Did you mean that if one
> takes melatonin at noon, then endogenous production of melatonin will be started
> next day(noon)? If so, taking melatonin to treat jet lag may result in long-
> term sleep disturbance. Would you explain about this in more detail?
** What researchers have found is that there is a distinct "phase=
response curve" to the effects of melatonin. Taking melatonin at certain
times of day will cause your own production to begin earlier or later,
depending on the time you take the hormone. However, taking melatonin
at bedtime, in synchrony with your body's own schedule, does not appear
to alter the timing.
[For more information about the melatonin response curve, check out
Chronobiology International 1992; 9:380-92.]>
> 2. I have heart that melatonin is synthesized from serotonin. Is there any
> known regulatory step or element in the synthesis of melatonin.
> ** The rate limiting step in the production of melatonin appears to
be the enzyme NAT -- N-acetyltransferase.
["Pineal Melatonin: Cell biology of its synthesis and of its
physiological interactions" Endocrine Reviews 1991; 12:151-180]
> 3. You explained that melatonin level was decreased in many disease conditions
> including many neuro-psychiatric disease. It is very interesting to me because
> I am major in neuroscience. I want to know more about the exact relationship
> between decreased melatonin and the disease. However the book you recommended
> is not available in Korea. Do you have any other reference for it?
> ** IN our book, Melatonin: Your Body's Natural Wonder Drug, we
list scientific references for all of the diseases and conditions known
to be characterized by low melatonin. (It would take me too long to list
them here.) I can arrange to have a book shipped to Korea if you are
interested.
> 4. Would you let me know more about melatonin receptor? Is it cloned? How many
> subtypes? Which signal transduction pathway is linked to receptor?
> ** One of the melatonin receptors has just been cloned. There
appear to be a number of discrete receptors, including a recently
identified nuclear receptor. (There are only a few hormones known to
have nuclear receptors.)
[For references: "Melatonin receptors: current status, facts,
and hypothesis." Life Sciences 1990; 46:971-982.
"Structural requirements at the melatonin receptor" Br.
J. of Pharmacology 1995; 114:618-623.
"...melatonin binds and activates an orphan of the nuclear
receptor superfamily" J. of Biological Chemistry 1994; 269:28531
"Expression cloning of a high-affinity melatonin receptor.."
Proc. Natl. Acad. Sci 1994; 91:6133-37"
I also suggest that you contact Russel Reiter at the UTHSC
at San Antonio. He is the world's leading authority on melatonin, and,
as time permits, welcomes questions from other researchers.
1-210-567-3859.
Best wishes,
JO
+-----------------------------------+-----------------------------------------+
| Jo Robinson | jor at teleport.com |
| (503)284-4676 | 2826 NE 18th Portland, OR 97212 |
+-----------------------------------+------------------------------------y-----+
