- The influence of some pterins on the circadian rhythmicity of hydroxyindole-O-methyl transferase in the pineal gland of 42-day old male Wistar rats. Balemans, M.G., Van Benthem, J., Legerstee, W.C., de Moree, A., Noteborn, H.J., Ebels, I. Reproduction, nutrition, development. (1980)