= J. L. Weller
{c}
<J. L. Weller> coauthored, with <D. C. Klein>, a 1970 investigation of <circadian rhythms> in the rat <pineal gland>. The experiment measured <serotonin N-acetyltransferase> activity over time rather than inferring all biochemical events from the final amount of <melatonin>.<Indole metabolism in the pineal gland: a circadian rhythm in N-acetyltransferase by D. C. Klein and J. L. Weller>[Original byline and Abstract]{ref}
Night-time activity exceeded daytime activity by more than fifteenfold. Persistence in darkness and in blinded animals, together with suppression by constant light, supplied controls on how the rhythm related to environmental illumination.<Indole metabolism in the pineal gland: a circadian rhythm in N-acetyltransferase by D. C. Klein and J. L. Weller>[Abstract: enzyme activity and lighting manipulations]{ref}
An enzyme-activity measurement asks what a preparation can do under the assay conditions. It is different from measuring how much <enzyme> is present or how much product has accumulated in an intact animal. That distinction makes the work an example of connecting a daily biological pattern to a defined biochemical readout.
Back to article page
