Relative Efficacy of Melatonin and 5-Methoxytryptamine in Terms of Their Antigonadotrophic and Counterantigonadotrophic Actions in Male Syrian Hamsters
Version of Record online: 30 JAN 2007
Journal of Pineal Research
Volume 1, Issue 1, pages 91–98, January 1984
How to Cite
Reiter, R. J., Holtorf, A., Champney, T. H. and Vaughan, M. K. (1984), Relative Efficacy of Melatonin and 5-Methoxytryptamine in Terms of Their Antigonadotrophic and Counterantigonadotrophic Actions in Male Syrian Hamsters. Journal of Pineal Research, 1: 91–98. doi: 10.1111/j.1600-079X.1984.tb00199.x
- Issue online: 30 JAN 2007
- Version of Record online: 30 JAN 2007
- Received November 10, 1983; accepted January 22, 1984.
- pineal gland;
- Syrian hamster
Antigonadotrophic and counterantigonadotrophic activities of melatonin and 5-methoxytryptamine (5-MT) were quantitatively compared in male Syrian hamsters. In long day conditions, the daily afternoon administration of either 5, 15, 25, 50, 100 or 200 μg melatonin induced testicular regression within 10 wk; under the same circumstances, only the 200-μg dosage of 5-MT was able to suppress testicular weights. Thus, 5-MT appears to have about one-tenth the antigonadotrophic action of melatonin in the male Syrian hamster. In short days, the subcutaneous implantation of either 50 or 100 μg melatonin (every 2 wk in beeswax) prevented testicular regression whereas it required much larger doses of 5-MT (1 mg every 2 wk in beeswax) to achieve the same counterantigonadotrophic action. In terms of both their antigonadotrophic and counterantigonadotrophic effects, hamsters seem to be more sensitive to melatonin than to 5-MT.