In vitro uptake of 18-hydroxycorticosterone by regions of the central nervous system.

The specific uptake of tritiated 18-hydroxycorticosterone (18-OH-B) by purified cell nuclear fractions and cytosol of medulla oblongata, pons, amygdala, anterior pituitary, hypothalamus, hippocampus, preoptic-area and lung from adrenalectomized animals was investigated after incubation of tissue sections with radioactive ligand. We found that 18-OH-B was taken up mainly by nuclei obtained from pons and medulla oblongata; this profile differs from previous observations with the closely related steroids corticosterone and aldosterone, which are mostly concentrated by the limbic system. Based on this finding, as well as on former studies with 18-OH-B, we suggest that this steroid may exert its action on renal excretion of protons as well as on central nervous system structures involved in respiratory regulation, related to that excretion.