TAGESPERIODISCHE SCHWANKUNGEN DER URINAUSSCHEIDUNG UND DES ADIURETINGEHALTES IM HYPOPHYSENHINTERLAPPEN MÄNNLICHER WISTAR-RATTEN

Abstract

ABSTRACT Adult male Wistar rats were kept at a constant temperature and in an alternating light-dark environment consisting of 12 hours of light with 150 lux (7 a. m. – 7 p. m.) and 12 hours of darkness with 0.1 lux (7 p. m. – 7 a. m.). The urine output was measured at 4-hourly intervals over several 24-hour periods. Diurnal changes with a high excretion at midday and a low excretion at midnight were found. The content of antidiuretic hormone of the posterior pituitary lobe was estimated at 10 a. m., 2 p. m., 6 p. m., and at 10 p. m., 2 a. m., 6 a. m. in the months of March, April and May. The highest amount occurred during darkness with maximal values at 6 a. m., the lowest during light with minimal values at 2 p. m.