The rat pineal N-acetyltransferase rhythm persists after a five-hour, but disappears temporarily after a seven-hour advance of the light-dark cycle: a six-hour shift may be a turning point.
After a 5-h advance of a lighting regime with 12 h of light and 12 h of darkness by shortening of one dark period, the rat pineal N-acetyltransferase (NAT) rhythm was retained, though at the beginning in a changed waveform, and re-entrained to the shift within 5 to 6 cycles. After a 7-h advance of the regime, the NAT rhythm faded away between the 2nd and 4th cycle and re-entrained to the shift within 7 cycles. A 6-h advance of the lighting regime might thus be a turning point for the persistence or temporal disappearance of the NAT rhythm.
Illnerová
H
H
Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
Humlová
M
M
D000123:Acetyltransferases / Q000378:metabolism*; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D002940:Circadian Rhythm; D008029:Lighting; D008297:Male; D010870:Pineal Gland / Q000201:enzymology / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D000123:Acetyltransferases; D001191:Arylamine N-Acetyltransferase