Estradiol-induced redistribution of lysosomal proteins in rat preputial gland. Evidence from immunologic probes.

Abstract

The influence of estrogen on the subcellular localization and distribution of lysosomal components of preputial gland was investigated in the ovariectomized rat. Antisera of high titer and specificity toward high-density lysosomal lipoproteins of this organ were raised in rabbits. The immunologic effectiveness of the IgG [immunoglobulin G] fraction so obtained was confirmed by microcomplement fixation, immunodiffusion and immunoelectrophoresis. By both direct and indirect immunofluorescence techniques, cryostat sections of preputial gland from the control animals exhibited pinpoint cytoplasmic fluorescence, of dimensions corresponding to those of lysosomes. In contrast, specific immunoreactive material in corresponding target cells from animals receiving 0.1 .mu.g of estradiol-17.beta./100 g body wt only 2 min earlier was distributed more homogeneously, indicating release of antigen from the membrane-bounded organelles. Moreover, specific immunofluorescence became evident at cell surfaces and in peri- and supranuclear localization, sites essentially negative in the controls. These effects were intensified at 15 min and by the maximal physiologic dose (0.5 .mu.g/100 g body wt) of hormone. The relatively less active epimer, estradiol-17.alpha., exhibited only very limited effectiveness by some of these criteria. Structural labilization of lysosomal constituents and their translocation to the nuclear compartment are early correlates of estrogen action.