The suppression of pineal melatonin content and N-acetyltransferase activity by different light irradiances in the Syrian hamster: a dose-response relationship.
The purpose of this study was to test the influence of various irradiances of cool white fluorescent light on the suppression of pineal N-acetyltransferase activity (NAT) and melatonin content in hamsters. Groups of animals were exposed to light irradiances ranging from 0.00-1.86 microwatts (microW)/cm2 for 20 min during the night. Both pineal NAT and melatonin were similarly depressed by the light irradiances in a dose-related manner. The shape of the resultant dose-response curves and the calculated ED50 for NAT (0.066 microW/cm2) and melatonin (0.058 microW/cm2) were remarkably similar. These findings may be relevant to the physiological control of the pineal by natural illumination.
D000123:Acetyltransferases / Q000378:metabolism*; D000818:Animals; D006224:Cricetinae; D004307:Dose-Response Relationship, Radiation; D008297:Male; D008433:Mathematics; D008550:Melatonin / Q000032:analysis*; D008647:Mesocricetus; D010775:Photic Stimulation; D010870:Pineal Gland / Q000032:analysis* / Q000528:radiation effects
D000123:Acetyltransferases; D008550:Melatonin