ELECTROLYTE DETERMINATIONS IN PITUITARY AND PINEAL-GLAND - IS THERE A DIURNAL RHYTHM

  • 1 January 1976
    • journal article
    • research article
    • Vol. 67  (1) , 51-59
Abstract
At 4 different times during the day determinations of the electrolyte content of the rat anterior and posterior pituitary and of the pineal were carried out by atomic absorption spectroscopy. There are significant differences in the Na and K content between these organs. There are distinct changes in the adenohypophysial Na+, K+ and Mg2+ content between the light and the dark period. Values are low during the day and high during the night. In the light period there is a higher Na concentration in the neurohypophysis and a greater K concentration of the pineal tissue. Despite a similar phylogenetic development, the neurohypophysis has considerably less univalent cations than the pineal gland. Data from the literature suggest that there are not greater differences in the H2O content of neurohypophysis and pineal. The possibly resulting hypotonicity of neurohypophysial tissue and its possible implications for the mode of the release of hormonal substances from the neurohypophysis are discussed.