Uterine fluid from progesterone treated rabbits contains subcellular membranes

Summary Uterine fluid from progesterone treated rabbits was shown to be rich in subcellular membrane components consisting of vesicles and cilia-like fragments. In contrast, uterine fluid from untreated does lacked subcellular membranes. Thus, they arise when uterine sperm capacitation ability is suppressed.The assistance of Mr R. Byrne is gratefully acknowledged. Mr K. Bedigian skilfully prepared the electron micrographs. Financial support was received from N.I.H. grant HD 10206-01.     

Uterine fluid proteins bind sperm cholesterol during capacitation in the rabbit

Summary Cholesterol from rabbit sperm cells was bound by uterine fluid proteins following intrauterine insemination into ovulating does. Serum albumin has been identified as a uterine sterol acceptor. Progesterone administration suppressed binding and elevated the concentration of cholesterol, phospholipid, and protein. Uterine fluid cholesterol affinity, therefore, correlated with sperm capacitation activity in utero.I thank N. V. Davis for her assistance during this study. Financial support was received from N.I.H. grant HD 16238.     

Uterine secretion during the sexual cycle in the rat and its capacity to disperse corona cells in vitro.

It was found that closure of the uterus disturbed the first 2 cycles after the operation; thereafter the normal cycle was resumed. The quantity of uterine fluid was increased at pro-oestrus and oestrus and reduced at met-oestrus and di-oestrus. Slight inverse changes in viscosity were observed. There was no significant difference in the pH. The corona-cell dispersing factor seems to be an oestrogen-dependent constituent of uterine secretion.     

Uterine secretion during the sexual cycle in the rat and its capacity to disperse corona cells in vitro

Summary It was found that closure of the uterus disturbed the first 2 cycles after the operation; there-after the normal cycle was resumed. The quantity of uterine fluid was increased at pro-oestrus and oestrus and reduced at met-oestrus and di-oestrus. Slight inverse changes in viscosity were observed. There was no significant difference in the pH. The corona-cell dispersing factor seems to be an oestrogen-dependent constituent of uterine secretion.     

Are prostaglandins involved in early estrogen action

Summary Prostaglandin biosynthesis inhibition by indomethacin blocks estrogen-induced uterine hyperemia, but does not block estrogen-induced uterine eosinophilia and edema.Acknowledgments. Supported by grant B 012815 from the Servicio de Desarrollo Cientifico, Artistico y de Cooperacion Internacional from the University of Chile.     

Effect of propranolol on various parameters of estrogen stimulation in the rat uterus

Summary Pretreatment with propranolol does not modify the estrogen-induced uterine eosinophilia, the water imbibition effect, nor the increase in uterine RNA and protein content. This confirms the independence of these parameters from the estrogen-induced early increase in uterine cAMP, since, when observed, the latter is suppressed by propranolol pretreatment.Acknowledgments. This work was supported by a contract of the Ministère de la Politique Scientifique, within the framework of the Association Euratom—University of Brussels—University of Pisa, and by grant 2015 from the Oficina Técnica de Desarrollo Científico y Creación Artística of the University of Chile.     

Dissociation of separate mechanisms of estrogen action by actinomycin D

Summary Pretreatment with actinomycin D 1 h before estrogen administration completely blocks estrogen-induced increases in uterine RNA and protein content, but does not counteract estrogen-induced uterine eosinophilia, edema and increase in glycogen content.Acknowledgments. This work was supported by the Belgian Ministry of Scientific Policy (Concerted Actions of Research) and by the Servicio de Desarrollo Cientifico, Artistico y de Cooperacion Internacional from the University of Chile.     

Visualization of subcellular NAD pools and intra-organellar protein localization by poly-ADP-ribose formation

Poly-ADP-ribose polymerases (PARPs) use NAD⁺ as substrate to generate polymers of ADP-ribose. We targeted the catalytic domain of human PARP1 as molecular NAD⁺ detector into cellular organelles. Immunochemical detection of polymers demonstrated distinct subcellular NAD⁺ pools in mitochondria, peroxisomes and, surprisingly, in the endoplasmic reticulum and the Golgi complex. Polymers did not accumulate within the mitochondrial intermembrane space or the cytosol. We demonstrate the suitability of this compartment-specific NAD⁺ and poly-ADP-ribose turnover to establish intra-organellar protein localization. For overexpressed proteins, genetically endowed with PARP activity, detection of polymers indicates segregation from the cytosol and consequently intra-organellar residence. In mitochondria, polymer build-up reveals matrix localization of the PARP fusion protein. Compared to presently used fusion tags for subcellular protein localization, these are substantial improvements in resolution. We thus established a novel molecular tool applicable for studies of subcellular NAD metabolism and protein localization.     

Ultrastructural studies of Morris hepatoma cells reversely transformed by ginsenosides

Ginsenosides, which were extracted from Panax ginseng C.A. Meyer, induced well the development of subcellular organelles in cultured Morris hepatoma cells (MH1C1).     

Colchicine-estrogen interactions

Summary Colchicine does not block estrogen-induced recognition of uterine blood vessel surface by eosinophils, but interfers with their migration through endothelial lining and therefore blocks estrogen-induced uterine eosinophilia and edema.Acknowledgments. This work was supported by grant 4002 from the Servicio de Desarrollo Científico y Creación Artística of the University of Chile. Technical help of Mr D. Sáez is appreciated.     

The localization of [3H]-desipramine in central nerve terminals studied with electron microscope autoradiography and subcellular fractionation.

The cellular and subcellular distribution of [3H]-desipramine (DMI) in rat brain was studied by electron microscope (EM) autoradiography and by subcellular fractionation. A considerable proportion of label was found to be bound to the membranes of presynaptic nerve terminals, as well as to sites inside those terminals.     

Effect of various doses of catecholestrogens on uterine eosinophilia in the immature rat

Summary This paper describes the induction of uterine eosinophilia as well as of deep endometrial edema and increase of uterine wet weight in the immature rat by the catecholestrogens 2-OH-estradiol and 4-OH-estradiol. These effects are thought to be mediated by eosinophils via a specific eosinophil receptor system. 4-OH-estradiol was equipotent with estradiol, whereas the effect of 2-OH-estradiol was significantly weaker.Acknowledgments. This work was supported by Grant B-1493-8435 from the University of Chile. We are indebted to Prof. R. Knuppen, Lübeck, for providing the CE.     

Colchicine-estrogen interactions.

Colchicine does not block estrogen-induced recognition of uterine blood vessel surface by eosinophils, but interfers with their migration through endothelial lining and therefore blocks estrogen-induced uterine eosinophilia and edema.     

Effect of theophylline and triiodothyronine on some early estrogenic responses in the rat uterus

Theophylline increases and triodothyronine decreases uterine edema induced by physiological doses of estradiol-17 beta. Both of them decrease estrogen-induced uterine eosinophilia and the number of blood eosinophils, suggesting an explanation for the results in the uterus.     

Asymmetric distribution of male and female foetuses in the pregnant rabbit uterus

Summary The sex distribution of foetuses in the uterine horn of the pregnant rabbit was found to be asymmetrical, with more males being present in the left uterine horn and more females in the right (p<0.05).     

The localization of [3H]-desipramine in central nerve terminals studied with electron microscope autoradiography and subcellular fractionation

Summary The cellular and subcellular distribution of [³H]-desipramine (DMI) in rat brain was studied by electron microscope (EM) autoradiography and by subcellular fractionation. A considerable proportion of label was found to be bound to the membranes of presynaptic nerve terminals, as well as to sites inside those terminals.Acknowledgment. The authors are most grateful to Mr and Mrs Gudelsky for their generous support.     

Hormone-induced subcellular redistribution of trimeric G proteins

Trimeric guanine nucleotide-binding proteins (G proteins) function as the key regulatory elements in a number of transmembrane signaling cascades where they convey information from agonist-activated receptors to effector molecules. The subcellular localization of G proteins is directly related to their functional role, i.e., the dominant portion of the cellular pool of G proteins resides in the plasma membrane. An intimate association of G protein subunits with the plasma membrane has been well known for a long time. However, results of a number of independent studies published in the past decade have indicated clearly that exposure of intact target cells to agonists results in subcellular redistribution of the cognate G proteins from plasma membranes to the light-vesicular membrane fractions, in internalization from the cell surface into the cell interior and in transfer from the membrane to the soluble cell fraction (high-speed supernatant), i.e., solubilization. Solubilization of G protein α subunits as a consequence of stimulation of G protein-coupled receptors (GPCRs) with agonists has also been observed in isolated membrane preparations. The membrane-cytosol shift of G proteins was detected even after direct activation of these proteins by non-hydrolyzable analogues of GTP or by cholera toxin-induced ADP-ribosylation. In addition, prolonged stimulation of GPCRs with agonists has been shown to lead to down-regulation of the relevant G proteins. Together, these data suggest that G proteins might potentially participate in a highly complex set of events, which are generally termed desensitization of the hormone response. Internalization, subcellular redistribution, solubilization, and down-regulation of trimeric G proteins may thus provide an additional means (i.e., beside receptor-based mechanisms) to dampen the hormone or neurotransmitter response after sustained (long-term) exposure. Received 31 August 2001; received after revision 31 October 2001; accepted 7 November 2001     

Hydroxyproline concentration in soluble and insoluble material from serum treated with trichloroacetic acid in postpartum mice

The hydroxyproline concentration in both the soluble and insoluble material from trichloroacetic acid-treated serum from postpartum mice was determined. The hydroxyproline concentration in the insoluble material increased, but that in the soluble material did not increase during the uterine involuting period.     

Hydroxyproline concentration in soluble and insoluble material from serum treated with trichloroacetic acid in postpartum mice

Summary The hydroxyproline concentration in both the soluble and insoluble material from trichloroacetic acid-treated serum from postpartum mice was determined. The hydroxyproline concentration in the insoluble material increased, but that in the soluble material did not increase during the uterine involuting period.     

Correlation of estrogen-induced uterine eosinophilia with other parameters of estrogen stimulation, produced with estradiol-17beta and estriol.

Estradiol-17beta is a stronger estrogen than estriol for the genomic response of estrogens. Estriol is a stronger estrogen than estradiol-17beta for the estrogen-induced uterine eosinophilia and the 6 h increase in the uterine wet weight.