bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Twenty-Four-Week Treatment with the Antiestrogen EM-800 on Estrogen-Sensitive Parameters in Intact and Ovariectomized Mice
Authors: Luo Shouqi , Sourla Antigone , Labrie Claude , Gauthier Sylvain , Merand Yves , Belanger Alain , Labrie Fernand 
Published: January 2014

AbstractTreatment with the antiestrogen EM-800, at the daily oral dose of 3μ g, 10 μg, 30 μg, or 100 μg for 24 weeks, caused a marked inhibition of uterine and vaginal weight in both intact and ovariectomized mice. Maximal 64% and 41% inhibitions of uterine weight were achieved in intact and ovariectomized animals, respectively. Similar inhibitory effects of EM-800 were observed on vaginal weight with maximal inhibitions of 71% and 35%, in intact and ovariectomized animals, respectively. The pure antiestrogenic activity of EM-800 on the hypothalamo-pituitary-ovarian axis is illustrated by the 76–91% increases in ovarian weight observed in intact animals treated with the 10–100 μg doses of the antiestrogen. Serum 17β-estradiol was 93% increased at the 100 μg daily dose of EM-800, whereas serum androstenedione, testosterone, and dihydrotestosterone were 141–713% increased over control at the same dose of the antiestrogen. Serum LH was increased by treatment with EM-800 in intact animals, whereas no effect was observed on the elevated gonadotropin levels in ovariectomized animals. At all doses used in intact animals, the antiestrogen caused a complete disappearance of the glandular elements of the mammary gland, the atrophy being comparable with that observed in ovariectomized mice. The mammary gland of EM-800-treated animals was exclusively composed of an atrophied ductal system lined by atrophied epithelial cells with an absence of lobulo-glandular elements. No effect of the compound was observed on the histology of the mammary gland in ovariectomized animals, thus showing the pure antiestrogenic effect of EM-800 on the mammary gland, as shown also for the uterus, vagina, and hypothalamo-pituitary axis. At histopathology, all doses of EM-800 in intact animals led to a moderate to severe uterine and vaginal atrophy. The uterine atrophy affected both the myometrium and the endometrium. Interestingly, the uterine atrophy achieved in intact animals treated with EM-800 was greater than that observed after ovariectomy alone, thus clearly demonstrating the pure antiestrogenic activity of EM-800. The present data show the highly potent and pure antiestrogenic activity of EM-800 on all parameters measured after 6 months of treatment in both intact and ovariectomized mice, a maximal effect being reached at the daily 10 μg dose of the antiestrogen in intact animals.
Glucose Metabolism in Goto-Kakizaki Rat Islets*
Authors: Zong-Chao Ling , Efendic Suad , Wibom Rolf , Abdel-Halim Samy M. , Östenson Claes-Göran , Landau Bernard R. , Khan Akhtar 
Published: January 2014

AbstractIslets from Goto-Kakizaki (GK) rats from our colony, despite marked impairment of glucose-induced insulin release, used glucose and produced CO2 at a rate 3 times that of islets from control Wistar rats. Almost all glucose used was accounted for in CO2 and lactate production. The percentages of glucose carbon used collected in CO2 and lactate were similar for control and GK islets. GK islets also oxidized 40% more acetate and leucine to CO2 than did control islets. The fraction of carbon leaving the Krebs cycle relative to CO2 production was the same in GK and control islets. The capacities of mitochondria from GK islets to generate ATP from glutamate and malate were similar and that to generate ATP from succinate and rotenone was somewhat less from GK islets. The reason for the enhanced utilization of substrates by islets of the GK rat is not apparent. In conclusion, there is no decrease in islet glucose utilization, glucose oxidation, Krebs cycle function, or the electron transport system evident from these measurements to explain the impaired insulin release in islets from GK rats.
Obesity and Insulin Resistance in Human Growth Hormone Transgenic Rats*
Authors: Ikeda Akihiro , Chang Kyu-Tae , Matsumoto Yoshiki , Furuhata Yasufumi , Nishihara Masugi , Sasaki Fumihiko , Takahashi Michio 
Published: January 2014

AbstractA line of transgenic rats (heterozygotes) carrying a chimeric gene comprising a regulatory portion of murine whey acidic protein and a structural portion of human GH (hGH) genes developed severe obesity with age. To characterize physiological mechanisms that lead to fat accumulation, an array of parameters related to obesity were studied. Blood hGH levels were continuously low, endogenous rat GH secretion was suppressed, and the pulsatility in peripheral GH levels was absent. Plasma glucose, insulin, triglyceride, and FFA levels in the male transgenic rats significantly exceeded those in nontransgenic littermates at 12 and 17 weeks, but not at 7 weeks, of age. All symptoms except hyperlipidemia were restored to normal by treatment with an antidiabetic agent, thiazolidinedione (troglitazone), for 1 week from 17 weeks of age. As phenotypic expression of obesity was already evident before aberration of physiological parameters, it was assumed that animals had a condition in which obesity or hyperlipidemia caused hyperinsulinemia. Gene expression and enzymatic activity of lipoprotein lipase in the adipose tissue in the transgenic rats were not different from those in normal rats. In contrast, the gene expression level of glycerol-3-phosphodehydrogenase was markedly elevated, suggesting that glycerol synthesis was much enhanced in the adipocytes of the transgenic rats. In an ip glucose tolerance test, the transgenic rats were not hyperglycemic at 7 weeks of age; however, the animal became hyperglycemic at 15–17 weeks of age. Finally, treatment with recombinant hGH for 1 week to produce pulsatile secretion reduced the size of epididymal and kidney fat pads and restored normal weight gain. These observations suggest that continuously low peripheral GH levels with the lack of pulsatile secretion resulted in obesity and noninsulin-dependent diabetes mellitus.
Dehydroepiandrosterone Decreases Serum Tumor Necrosis Factor-α and Restores Insulin Sensitivity: Independent Effect from Secondary Weight Reduction in Genetically Obese Zucker Fatty Rats*
Authors: Kimura Mari , Tanaka Shun-ichi , Yamada Yoshihiko , Kiuchi Yoshihiro , Yamakawa Tadashi , Sekihara Hisahiko 
Published: January 2014

Abstract
Dehydroepiandrosterone (DHEA) and its sulfate ester are the most abundant circulating adrenal steroids in humans. Administration of DHEA has been reported to have beneficial effects on obesity, hyperlipidemia, diabetes, and atherosclerosis in obese rodents, although its effects on insulin resistance have not been fully elucidated.
In this study, the effects of DHEA treatment on insulin sensitivity were investigated in genetically obese Zucker rats, an animal model of insulin resistance, using the euglycemic clamp technique. After 0.4% DHEA was administered for 10 days to female obese Zucker rats aged 16 weeks, body weight and plasma insulin decreased and glucose disposal rate (GDR), which was normally reduced in obese rats, rose significantly compared with age- and sex-matched control obese rats. On the other hand, although the pair-fed obese rats also showed levels of weight reduction similar to those of DHEA-treated rats, the increase in GDR of DHEA-treated rats was significantly greater than in pair-fed rats, suggesting a direct ameliorating effect of DHEA on insulin sensitivity of obese rats. Serum concentration of tumor necrosis factor (TNF)-α, one of cytokines causing insulin resistance, was also reduced significantly in DHEA-treated, but not in pair-fed obese rats. In conclusion, our results suggest that DHEA treatment reduces body weight and serum TNF-α independently, and that both may ameliorate insulin resistance in obese Zucker fatty rats.
Immunoexpression of Aquaporin-1 in the Efferent Ducts of the Rat and Marmoset Monkey during Development, Its Modulation by Estrogens, and Its Possible Role in Fluid Resorption*
Authors: Fisher Jane S. , Turner Katie J. , Fraser Hamish M. , Saunders Philippa T. K. , Brown Dennis , Sharpe Richard M. 
Published: January 2014

AbstractRecent data suggest that estrogens play a role in regulating fluid resorption from the efferent ducts, though the biochemical mechanisms involved are unknown. The present study has used immunocytochemistry to localize a water channel protein, Aquaporin-1 (AQP-1), to the efferent ducts of male rats and marmoset monkeys from perinatal life through to adulthood and has then investigated its potential hormonal regulation in neonatal/peripubertal life, via administration of a GnRH antagonist (GnRHa) or diethylstilbestrol (DES) to rats. AQP-1 was immunoexpressed intensely in the apical brush border of the epithelium lining the efferent ducts at all ages studied, from late fetal life through puberty to adulthood. In the marmoset, but not the rat, AQP-1 was also expressed in the epithelium of the rete testis. Once the cell types within the efferent duct epithelium had differentiated, it was clear that only nonciliated cells of the rat localized AQP-1. When gonadotropin secretion was suppressed in rats by neonatal administration of GnRHa, immunoexpression of AQP-1 at age 18 and 25 days was virtually unchanged in intensity, though the efferent ducts were reduced in size. In contrast, when DES was administered neonatally to rats (up to day 12), immunoexpression of AQP-1 was reduced at day 10, virtually abolished at day 18, reduced markedly at day 25 and to a small extent at day 35; these findings were confirmed by Western blot analysis at day 18. The DES-induced decrease in immunoexpression of AQP-1 was accompanied by pronounced distension of the efferent ducts and rete, consistent with reduced fluid resorption. The epithelial cells of the efferent ducts in DES-treated rats were cuboidal rather than columnar in shape as in controls and were reduced significantly in height compared with controls at all ages through to adulthood. These findings suggest that estrogens may play a role in regulating fluid resorption from the efferent ducts during fetal/neonatal development and/or a role in the gross and functional development of the efferent ducts and rete testis. The present data also suggest that AQP-1 is one of the elements involved in the regulation of fluid resorption in the efferent ducts. The importance of fluid flow in fetal/neonatal development of the excurrent duct system of the male is also suggested by these observations.
Coordinate and Divergent Regulation of Corticotropin-Releasing Factor (CRF) and CRF-Binding Protein Expression in an Immortalized Amygdalar Neuronal Cell Line**Portions of this report were presented in abstract form at the 1997 and 1998 annual meetings of The Endocrine Society.
Authors: Mulchahey J. J. , Regmi A. , Sheriff S. , Balasubramaniam A. , Kasckow J. W. 
Published: January 2014

Abstract
CRF is a 41-amino acid neuropeptide best known for its hypophysiotropic actions. CRF is widely distributed in the central nervous system in areas beyond the hypothalamus. CRF-binding protein (CRF-BP) regulates the bioavailability of CRF, and knowledge of the regulation of CRF-BP synthesis is an integral component of understanding the actions of CRF. To better study the regulation of CRF and CRF-BP, primary amygdalar cultures were immortalized by transfection with the SV 40 large T antigen. A clonal line that expresses CRF immunoreactivity and messenger RNA was selected. The production of CRF peptide and message by this line is regulated in a manner indistinguishable from primary cultures. We also observed that the immortalized cells express CRF-BP immunoreactivity and messenger RNA. The expression of both CRF and CRF-BP is positively regulated by forskolin and interleukin-6. Unlike CRF, the expression of CRF-BP message and peptide was increased by phorbol 12-myristate 13-acetate or dexamethasone. These results demonstrate that the synthesis of CRF and CRF-BP in this clonal cell line may be regulated in parallel by some agents but not by others. These data also suggest that dexamethasone may decrease the biological availability of CRF in the amygdala by increasing the expression of CRF-BP, rather than by decreasing CRF expression.
Quantitative Analysis of Oxytocin and Vasopressin Messenger Ribonucleic Acids in Single Magnocellular Neurons Isolated from Supraoptic Nucleus of Rat Hypothalamus
Authors: Xi Dan , Kusano Kiyoshi , Gainer Harold 
Published: January 2014

Abstract
Oxytocin (OT) and vasopressin (VP) are peptide hormones that are derived from genes predominantly expressed in distinct magnocellular neurons in the paraventricular (PVN) and supraoptic (SON) nuclei of the hypothalamus. Recent evidence suggests that some magnocellular neurons coexpress both peptides. Our qualitative RT-PCR experiments on single cells show that the majority of magnocellular neurons coexpress both peptide messenger RNAs (mRNAs) in varying amounts. Using a competitive RT-PCR method combined with a standard calibration curve, we quantitatively determined OT and VP mRNA in single magnocellular neurons from the normal female rat SON, with a detection sensitivity of less than 30 mRNA molecules/cell. We defined the phenotypes of the single magnocellular neurons according to their ratios of these two peptide mRNAs. Using this approach, we identified three major phenotypes: oxytocin neurons, where the average OT to VP mRNA ratio is about 256; vasopressin neurons, where the average VP to OT mRNA ratio is about 182; and one oxytocin/vasopressin coexisting neuron, where the OT/VP mRNA ratio is 2. Thus, there is some OT and VP mRNA coexpression in virtually all of the magnocellular neurons in supraoptic nuclei of hypothalamus. However, clear phenotypes are identifiable by considering quantitative as opposed to qualitative differences.
Amphiregulin Is Coordinately Expressed with Heparin-Binding Epidermal Growth Factor-Like Growth Factor in the Interstitial Smooth Muscle of the Human Prostate1
Authors: Adam Rosalyn M. , Borer Joseph G. , Williams B. Jill , Eastham James A. , Loughlin Kevin R. , Freeman Michael R. 
Published: January 2014

AbstractPeptide growth factors have been proposed as mediators of smooth muscle-epithelial cell interactions in the human prostate; however, the identity of these molecules has not been established. In this study, we compared expression levels of messenger RNAs (mRNAs) encoding the epidermal growth factor (EGF) receptor-related receptor tyrosine kinases (ErbB1 through 4), the six EGF receptor ligands, EGF, transforming growth factor (TGF)-α, amphiregulin (ARG), HB-EGF, betacellulin, and epiregulin, and the related molecule heregulin-α, in a series of 10 prostate tissue specimens. Only EGF showed a disease-specific association, with increased mRNA levels in four of five PCa specimens in comparison to matched normal tissue from the same subject. In contrast, ARG and HB-EGF mRNAs showed a coordinate pattern of expression in 7/10 specimens that was distinct from all other growth factor or receptor genes examined and from mRNAs for prostate specific antigen, the androgen receptor and GAPDH, a housekeeping enzyme. Analysis of an additional series of benign prostatic hyperplasia and prostate cancer specimens from 60 individuals confirmed that ARG and HB-EGF mRNA levels varied in a highly coordinate manner (r = 0.93; P &lt; 0.0001) but showed no association with disease. ARG was immunolocalized largely to interstitial smooth muscle cells (SMC), previously identified as the site of synthesis of HB-EGF in the prostate, while the cognate ARG and HB-EGF receptor, ErbB1, was localized exclusively to ductal epithelial cells and carcinoma cells. Although ARG was a relatively poor mitogen for Balb/c3T3 cells in comparison to HB-EGF, it was similar in potency to HB-EGF in stimulating human prostate epithelial cell growth, suggesting that prostate epithelia may be a physiologic target for ARG in vivo. Expression of both ARG and HB-EGF mRNAs was induced in cultured prostate SMC by fibroblast growth factor-2, a human prostate SMC mitogen linked to prostate disease. These findings indicate that ARG and HB-EGF are likely to be key mediators of directional signaling between SMC and epithelial cells in the human prostate and appear to be coordinately regulated.
Orexin Receptors Are Expressed in the Adrenal Medulla of the Rat
Authors: López M. , Señaris R. , Gallego R. , García-Caballero T. , Lago F. , Seoane L. , Casanueva F. , Diéguez C. 
Published: January 2014

Abstract
Two recently discovered hypothalamic peptides, orexin-A and orexin-B, play a role as mediators in the central mechanisms that regulate feeding behavior and sleep control. These peptides bind and activate two orexin receptors that belong to the G-protein coupled receptor superfamily. Morphological studies have detected mRNA expression of orexin receptors exclusively in the rat central nervous system. In this paper we demonstrate a strong level of expression of orexin receptor 1 and 2 in the adrenal medulla of the rat by RT-PCR immunohistochemistry. The results of the present study provide the first evidence showing that the adrenal medulla expresses orexin receptors, and thus appears to be a target tissue for orexins. This could open a new loop in which the central and autonomous nervous system may be involved in body weight homeostasis and sleep control.
Induction of Rat Aldose Reductase Gene Transcription Is Mediated through the cis-Element, Osmotic Response Element (ORE): Increased Synthesis and/or Activation by Phosphorylation of ORE-Binding Protein Is a Key Step
Authors: Aida Kaoru , Tawata Masato , Ikegishi Yukinobu , Onaya Toshimasa 
Published: January 2014

AbstractWe isolated the rat aldose reductase gene and examined the 5′-flanking sequence for the presence of transcription regulatory element responsive to hyperosmolarity. Deletion of aldose reductase gene up to− 1047 bp abolished the transcriptional activation in response to osmotic stimuli in transient transfection experiments. A 17-bp sequence[ rat osmotic response element (rORE)], which is located in bp− 1073/−1057 and contains the TGGAAAATCAC sequence, confers osmotic response on a heterologous promoter. Electrophoretic mobility shift assays using the 17-bp fragment demonstrated that distinct DNA-protein complexes (I and II) were formed predominantly with nuclear extracts from the cells exposed to hyperosmolarity. When the nuclear extracts were preincubated with calf intestinal alkaline phosphatase or protein phosphatase 1, formation of complexes I and II was reduced to the control level. However, incubation with protein tyrosine phosphatase and addition of antiphosphotyrosine antibody had no effect on the complexes. When the nuclear extracts were preincubated with diamide to oxidize the thiols, complexes I and II were not affected. Pretreatment of the cells with cycloheximide abolished the complexes. All of these data indicate that activation by phosphorylation and/or increased synthesis of rORE-binding protein(s) are the key steps in induction of transcription of the rat aldose reductase gene by hyperosmolarity. Furthermore, we showed that glucose was more effective than NaCl in induction of aldose reductase both in transient transfection experiments and by Northern blot analysis. The results suggest the presence of a glucose-specific mechanism of induction in addition to that by NaCl.
Role of Signal Transduction in Internalization of the G Protein-Coupled Receptor for Parathyroid Hormone (PTH) and PTH-Related Protein*
Authors: Huang Zhengmin , Bambino Tom , Chen Ying , Lameh Jelveh , Nissenson Robert A. 
Published: January 2014

AbstractFor G protein-coupled receptors, limited information is available on the role of agonist binding or of the second-messenger products of receptor signaling on receptor endocytosis. We explored this problem using the opossum PTH/PTH-related protein (PTHrP) receptor, a prototypical Class II G protein-coupled receptor, as a model. In one approach, we evaluated the endocytic properties of mutated forms of the opossum PTH/PTHrP receptor that we had previously shown to be impaired in their ability to initiate agonist-induced signaling when expressed in COS-7 cells. A point mutation in the third cytoplasmic loop (K382A) that severely impairs PTH/PTHrP receptor signaling significantly reduced internalization, whereas two mutant receptors that displayed only partial defects in signaling were internalized normally. To explore more directly the role of second-messenger pathways, we used a cleavable biotinylation method to assess endocytosis of the wild-type receptor stably expressed in human embryonic kidney (HEK) 293 cells. A low rate of constitutive internalization was detected (&lt;5% over a 30-min incubation at 37 C); the rate of receptor internalization was enhanced about 10-fold by the receptor agonists PTH(1–34) or PTHrP(1–34), whereas the receptor antagonist PTH(7–34) had no effect. Forskolin treatment produced a minimal increase in constitutive receptor endocytosis, and the protein kinase (PK)-A inhibitor H-89 failed to block agonist-stimulated endocytosis. Similarly, activation of PK-C, by treatment with phorbol 12-myristate 13-acetate, elicited only a minimal increase in constitutive receptor endocytosis; and blockade of the PK-C pathway, by treatment with a bisindolylmaleimide, failed to inhibit agonist-induced receptor endocytosis. Immunofluorescence confocal microscopic studies of PTH/PTHrP receptor internalization confirmed the results using receptor biotinylation. These findings suggest that: 1) agonist binding is required for the efficient endocytosis of the PTH/PTHrP receptor; 2) receptor activation (agonist-induced receptor conformational change) and/or coupling to G proteins plays a critical role in receptor internalization; and 3) activation of PK-A and PK-C is neither necessary nor sufficient for agonist-stimulated receptor internalization.
The Gonadotropin-Releasing Hormone Receptor Gene Promoter Directs Pituitary-Specific Oncogene Expression in Transgenic Mice*
Authors: Albarracin Constance T. , Frosch Matthew P. , Chin William W. 
Published: January 2014

AbstractOur previous work has shown that 1.2 kb of the 5′ flanking region of the mouse GnRH receptor (mGnRH-R) gene is sufficient to direct tissue-specific expression in vitro. In this study, we have used the cell-specific regulatory sequences of the mGnRH-R gene promoter to target the expression of the simian virus 40 virus T antigen (TAg) to the pituitary gland of transgenic mice. A hybrid transgene, GnRH-R/TAg, was prepared using the −1164/+52 region of the mGnRH-R gene and +2533/+5234 sequences encoding the large T antigen of the simian virus 40. Two founders developed tumors of apparent pituitary origin at 44 (M28, female) and 50 (M25, male) days of age. M28 and M25 mice were about 50% underweight, and their gonads were grossly underdeveloped compared with wild-type litter mates. A third male founder, M29, developed a tumor at a later time (109 days). M29 was able to breed successfully and stably transmit the GnRH-R/TAg transgene. Mice of the M29 transgene line developed tumors at 4–5 months of age. Gross examination showed that the tumors extend from the sella and infiltrate into the inferior surface of the brain. In small tumors collected from young transgenic animals, normal pituitary cells as well as transition areas of increasing cellular atypia are evident. Frankly malignant cells are seen in all tumors. The pituitary tumors express the α-, FSHβ-, and LHβ-subunits and the GnRH-R messenger RNA, all markers of a gonadotrope but not of other anterior pituitary cell lineages. In summary, our studies indicate that 1.2 kb of the 5′-flanking region of the mGnRH-R gene can be used to target expression specifically to the gonadotropes of the pituitary gland in transgenic mice. The GnRH-R gene promoter-directed expression appears to be cell-specific and results in the formation of tumors that are primarily of gonadotropic origin.