[Progesterone receptors in normal human leptomeninges in adults].

Cytosolic and/or nuclear 3H-R 5020 binding sites were detected in 6/6 samples of normal leptomeninges obtained at the time of operation in human adults. The levels of binding sites were higher in leptomeninges samples (range of values: 140-1780 fmol/gT) than in the corresponding intracranial tumors (one meningioma, two neurinomas, one metastasis) in 3 out of the 4 cases that were simultaneously studied. The 3H-R 5020 binding systems were characterized in 2 groups, A and B, of pooled samples representing respectively 4 and 17 samples of normal leptomeninges. The study of A (cytosolic and nuclear binding sites) and B (cytosolic binding sites) groups showed that binding systems had a limited capacity and a high affinity (Kd were respectively 2 X 10(-9) and 5.3 10(-10) M) as previously noted for the progestin receptor in human meningioma. Biochemical data and ultrastructural pictures obtained in the present study as well as in previous works, allow to consider the presence of the progestin receptor in normal leptomeninges.