An interesting read...
An interesting read...
This quote kind of made me think the author hasn't takenyet, "As an over-the-counter supplement, it is used widely to stave off jetlag from long airline flights, and is popped nightly by many nightshift workers to keep alert."
Nonetheless, that was a good read and I hope the effects it has on birds aren't the same as when humans consume it.
Didn't even notice that to be honest....Originally Posted by ivydude
I liked a few of these
Melatonin regulates the sleep-wake cycle, or circadian rhythms, in many animals, including humans. Produced at night by the pineal gland at the base of the brain, it makes us drowsy at night and, when levels drop in the morning, brings us back to alertness. As an over-the-counter supplement, it is used widely to stave off jetlag from long airline flights, and is popped nightly by many nightshift workers to keep alert.It really amazes me that melatonin is available in any pharmacy," Bentley said. "It is a powerful hormone, and yet people don't realize that it's as 'powerful' as any steroid.wouldnt the longer day males have bigger nuts than the short day ones?Quail raised in simulated short days, which would be expected to produce high levels of melatonin in the brain, had correspondingly higher levels of GnIH than did quail raised with longer periods of light, which would be expected to produce less melatonin. In addition, the short-day males had larger testicles than the long-day males
I agree, assuming GnIH works like a GnRH (gonadotropin-releasing hormone) antagonist, it should suppress endogenous test and LH secretion. This definately makes me second guess taking melatonin post-cycle. Wish there was more research on GnIH.Originally Posted by Funny Monkey
To assess its gonadotropin-inhibiting potency in man, three different doses of a GnRH antagonist [( Ac-D2-Nal1,D4-Cl-Phe2, D3-Pal3, Arg5,D4-p-methoxybenzoyl-2-amino butyric acid6,D-Ala10]GnRH; Nal-Glu GnRH antagonist) were given to six normal men. Single sc doses of 0.5, 1.5, and 5.0 mg Nal-Glu GnRH decreased mean serum immunoactive LH (iLH) to 45.0 +/- 5.7% (+/- SE), 37.0 +/- 4.9%, and 31.3 +/- 4.2% of baseline, respectively. Maximal suppression occurred between 4 and 8 h after drug injection. Serum bioassayable LH concentrations significantly diminished 8 h after injection of 1.5 and 5.0 mg GnRH antagonist, but not after the 0.5-mg dose. Mean serum testosterone (T) fell to 39.8 +/- 5.0%, 32.1 +/- 4.9%, and 20.7 +/- 4.4% of baseline, respectively, after the 0.5-, 1.5-, and 5.0-mg doses. The decreases in serum iLH and testosterone (T) were more sustained after the higher doses; serum iLH and T were significantly suppressed 24 h after administration of the 5.0-mg dose. Twenty-four-hour integrated serum iLH and T concentrations decreased in a dose-dependent manner. However, basal and 24-h integrated serum FSH concentrations were not significantly affected by the drug. No adverse systemic side-effects occurred. Thus, the Nal-Glu GnRH antagonist effectively decreases serum LH and T concentrations in a dose- and time-dependent manner, and it, therefore, has potential as a male contraceptive.
I don't remember exactly what the deal was in humans, but melatonin has different effects in different species when it comes to things like T levels and reproduction. Some animals only reproduce at certain times of year. Others, like humans, have a slight bias to reproduce at certain times of year but can reproduce at any time. (IIRC humans are slightly biased to reproduce around September, but don't quote me on that.) The theory of course being that you want the young to be born when they have the best chance of surviving. For some animals the timing is real important, for others not so much. Anyway it seems that changes in melatonin secretion, caused by changes in day length, are probably part of how this happens. In animals that hibernate, or change coat color with the seasons, melatonin is also probably part of how those things happen.
The short version being, melatonin's effects as far as T (or FSH or LH, etc) can be very different and even totally opposite in different animals. If you want to know what it does in humans, study humans. I have the Russel Reiter book around here somewhere. It's kinda old but I'll see if it says anything useful about melatonin and T levels in humans.