Microtubule and plasmalemmal reorganization: acute response to estrogen.

The acute ultrastructural effects of estrogen in endometrial epithelial cells were investigated by transmission electron microscopy (TEM), with special reference to the microtubule (MT) apparatus and the luminal surface. Ovariectomized rats anesthetized with pentobarbitol sodium were injected intravenously with estradiol-17 beta (E2 beta), 0.5 micrograms/100 g body wt.

Characterization and partial purification of the Drosophila Kc cell ecdysteroid receptor.

The molting hormones of insects, the ecdysteroids, are steroids whose action is mediated by an intracellular receptor. The Kc cell line of Drosophila melanogaster possesses ecdysteroid receptors and exhibits characteristic, receptor-dependent morphological and biochemical responses to the application of ecdysteroids. This paper describes the interaction of muristerone A (2 beta, 3 beta, 5 beta, 11 alpha, 14 alpha(20R,22R)- heptahydroxycholest-7-en-6-one), a phytoecdysteroid, with the Kc cell ecdysteroid receptor.

Monoclonal antibody toward lysosomal cathepsin B cross-reacts preferentially with distinct histone classes.

1. A set of monoclonal antibodies (Mab) was prepared against cathepsin B (CB) from rat preputial-gland, an organ characterized by rapidly-renewing cell populations, which is a uniquely enriched source of lysosomal enzymes, including CB. Minute amounts of CB are known to be transferred abruptly to the nuclear compartment in a variety of activated cells.

Antibodies against estradiol-binding lysosomal lipoproteins gain access to the nuclear compartment of preputial gland cells under estrogen influence.

The influence of estrogen in provoking nuclear recompartmentation of lysosomal components in hormone-sensitive cells was investigated by immunological analyses of isolated nuclei from the preputial glands of ovariectomized rats. Fixed smears were prepared from ultrapurified nuclei freed of outer membrane, 2-30 min after iv injection of placebo-control solution or submicrogram amounts of estradiol-17 beta. Cytoplasmic contamination was negligible in such preparations, as monitored by vital staining with acridine orange.

Lysosomal cathepsin B-like activity: mobilization in prereplicative and neoplastic epithelial cells.

Extracellular release of acid thiol proteinase activity by prereplicative and neoplastic epithelial cells was studied in serum-free, chemically defined media (CDM) in vitro. Cells isolated from urinary bladder of male bullfrogs and endometrium of ovariectomized rats each showed preferential secretion of cathepsin B-like (CB) activity within 30 min after exposure to carcinogenic nitrosamines (5 X 10(-4) M) or to mitogenic estrogen 1 X 10(-9) M), respectively. In contrast, release of such proteinase, and stimulation of cell proliferation were far less extensive in rat preputial gland cells treated with estradiol-17 beta.

Elevated serum cathepsin B1 and vaginal pathology after prenatal DES exposure.

Activities of the lysosomal enzymes, cathepsin B1 (CBI), beta-glucuronidase, and beta-N-acetyl-D-glucosaminidase, as well as sialyl transferase, alkaline phosphatase, and placenta-like alkaline phosphatase, were determined on blind-coded serums from 99 women exposed to diethylstilbestrol (DES) in utero and 40 unexposed subjects of comparable age range. Cathepsin B1 averaged 100%, 1040% (P less than 0.001), 2720 % (P less than 0.

The lysosomal membrane complex. Focal point of primary steroid hormone action.

At short intervals after the intravenous administration of oestradiol-17beta, diethylstilboestrol, testosterone or saline control solution to ovariectomized rats, highly purified lysosome samples were prepared in substantial yield from preputial glands, sex accessory organs rich in these organelles. The preparations were essentially devoid of mitochondrial contamination. Exposure in vivo to doses of these hormones varying from 0.