Journal
JOURNAL OF PINEAL RESEARCH
Volume 33, Issue 4, Pages 218-224Publisher
BLACKWELL MUNKSGAARD
DOI: 10.1034/j.1600-079X.2002.02921.x
Keywords
circadian rhythms; human fetus; melatonin; receptor subtypes
Categories
Ask authors/readers for more resources
The purpose of this study was to identify sites of action of melatonin in the human fetal brain by in vitro autoradiography and in situ hybridization. Specific, guanosine triphosphate (GTP) sensitive, binding of 2-[I-125] iodomelatonin was localized to the leptomeninges, cerebellum, thalamus, hypothalamus, and brainstem. In the hypothalalmus, specific binding was present in the suprachiasmatic nuclei (SCN) as well as the arcuate, ventromedial and mammillary nuclei. In the brainstem specific binding was present in the cranial nerve nuclei including the oculomotor nuclei, the trochlea nuclei, the motor and sensory trigeminal nuclei, the facial nuclei, and the cochlea nuclei. The localization of MT1 receptor subtype gene expression as determined by in situ hybridization matched the localization of 2-[I-125] iodomelatonin binding. No MT2 receptor subtype gene expression was detected using this technique. Thus, melatonin may act on the human fetus via the MT1 receptor subtype at a number of discrete brain sites. A major site of action of melatonin in both fetal and adult mammals is the pars tuberalis of the pituitary gland. However, no 2-[I-125] iodomelatonin binding or melatonin receptor gene expression was detected in the pituitary gland in the present study, indicating that the pituitary, particularly the pars tuberalis, is not a site of action of melatonin in the human fetus.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available