Pineal N-acetyltransferase activity in blinded and anosmic male rats

The pineal N-acetyltransferase activity in normal, blinded, anosmic, and anosmicblinded male rats has been examined 10 weeks after surgery at 4 times of the day. In normal animals, the values are about 2700 during the night and 100 during the day. Anosmia does not alter this rhythm. In blinded and blinded-anosmic animals, enzyme activity is not synchronized with time of day. During the 24-hr sampling period, 40% of the blinded and blinded-anosmic animals have enzyme values greater than 2000 units, and 45% have values less than 100 units. Blinded animals are known to have a synchronized diurnal rhythm in N-acetyltransferase 6 days after blinding. Thus it appears quite possible that, 10 weeks after surgery, the rhythm in blinded individual animals has become asynchronous relative to the rhythm in other blinded animals.