CIRCADIAN RHYTHM PATTERN OF ALPHA AMYLASE ACTIVITY IN THE SALIVARY GLANDS AND HEPATIC CAECA OF PERIPLANETA AMERICANA (BLATTARIA : BLATTIDAE) EXPOSED TO CONSTANT LL UNDER NORMAL AND EYE - BLOCKED CONDITIONS

OL-amylase enzyme is presentin the saliva and secretions of the hepatic caeca of the cockroach, Periplanella americana. The activity of this enzyme was measured every evening at 6 p.m. when the activity level was expected to be at its peak since cockroaches are nocturnal animals. Cockroaches were maintained under 24h LL conditions for 40 days. Initially enzyme activity in the salivary gland and hepatic caeca started decreasing This trend continued for about 10 to 12 days after which the activity level recuperated. Around the 30th day the enzyme activity was significantly high in the experimental group. In about 40 days the enzyme activity in both the tissues showed statistically non-significanthikes. The visual pigments of one of the eyes of another set of cockroaches were destroyed by a hot needle. These one eye-blocked cockroaches were exposed to 24h LL conditions. The enzyme activity in the two tissues in this set of cockroaches did not follow a specific pattern. But the enzymatic response was partly erratic. In another set of cockroaches both the eyes were blocked thereby exposing them to 24h DD conditions eventhough they are subjected to 24h LL conditions. This group showed minimum movements and consumed less food. The enzyme activity showed a drastic drop in both the tissues. This set of crockroaches could survive only for about 8 days. Light is an exogenous factor which serves as a Zeitgeber which may change the circadian rhythm of any physiological activity. Light enters into the body through the visual pigments of the eyes and registers its effect on the neural cells of the retina and subsequently the brain. Even in nocturnal animals t