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101.
102.
Richard?IvellEmail author Marga?Balvers Yvonne?Pohnke Ralph?Telgmann Olaf?Bartsch Karin?Milde-Langosch Ana-maria?Bamberger Almuth?Einspanier 《Reproductive biology and endocrinology : RB&E》2003,1(1):114
Background
The receptor for the peptide hormone relaxin has recently been identified as the heptahelical G-protein coupled receptor, LGR7. In order to generate molecular tools with which to characterize both in vivo and in vitro expression of this receptor in human and primate tissues, specific monotypic antibodies have been generated and applied to a preliminary analysis of human and primate female reproductive tissues. 相似文献103.
Kleinbongard P Dejam A Lauer T Rassaf T Schindler A Picker O Scheeren T Gödecke A Schrader J Schulz R Heusch G Schaub GA Bryan NS Feelisch M Kelm M 《Free radical biology & medicine》2003,35(7):790-796
Changes in plasma nitrite concentration in the human forearm circulation have recently been shown to reflect acute changes in endothelial nitric oxide synthase (eNOS)-activity. Whether basal plasma nitrite is a general marker of constitutive NOS-activity in vivo is yet unclear. Due to the rapid metabolism of nitrite in blood and the difficulties in its analytical determination literature data on levels of nitrite in mammals are largely inconsistent. We hypothesized that constitutive NOS-activity in the circulatory system is relatively uniform throughout the mammalian kingdom. If true, this should result in comparable systemic plasma nitrite levels in different species. Using three different analytical approaches we determined plasma nitrite concentration to be in a nanomolar range in a variety of species: humans (305 +/- 23 nmol/l), monkeys (367 +/- 62 nmol/l), minipigs (319 +/- 24 nmol/l), dogs (305 +/- 50 nmol/l), rabbits (502 +/- 21 nmol/l), guinea pigs (412 +/- 44 nmol/l), rats (191 +/- 43 nmol/l), and mice (457 +/- 51 nmol/l). Application of different NOS-inhibitors in humans, minipigs, and dogs decreased NOS-activity and thereby increased vascular resistance. This was accompanied by a significant, up to 80%, decrease in plasma nitrite concentration. A comparison of plasma nitrite concentrations between eNOS(-/-) and NOS-inhibited wild-type mice revealed that 70 +/- 5% of plasma nitrite is derived from eNOS. These results provide evidence for a uniform constitutive vascular NOS-activity across mammalian species. 相似文献
104.
Vegetative and generative dispersal capacity of field released transgenic aspen trees 总被引:2,自引:0,他引:2
Matthias?FladungEmail author Olaf?Nowitzki Birgit?Ziegenhagen Sandeep?Kumar 《Trees - Structure and Function》2003,17(5):412-416
Transfer of genes by pollen or wind-dispersed seed is considered a main potential risk when field release experiments with transgenic trees are initiated. In Germany, the first release experiment with genetically transformed trees was initiated in 1996. To ensure that the transgenic trees remained in the vegetative phase, the duration of the experiment was limited to 5 years. In total, 457 1-year-old trees including eight transgenic aspen lines carrying either the 35S- rolC or the rbcS- rolC gene construct, and three control clones were transferred to the field. In 1998 and 2000, 12 plants of transgenic lines all carrying the 35S- rolC gene construct formed female flower buds. Furthermore, one young aspen plant identified as a root sucker was observed in 1999 followed by an increasing number of root suckers derived from transgenic and non-transgenic trees in 2000 and 2001. In 2001, the last year of the field trial, 15 root suckers were detected outside the field. In total, 234 root suckers were harvested in 2000 and 2001 and analysed for their transgenic status. More than half of the roots suckers investigated showed the presence of the rbcS- rolC gene construct. We concluded that in addition to the widely accepted generative propagation, vegetative dispersal capacity of transgenic perennial plants is also important and must be included in risk assessment studies. 相似文献
105.
106.
107.
Olaf Sparre Andersen 《The Journal of general physiology》1998,111(1):1-18
The voltage dependence of the rat renal type II Na+/Pi cotransporter (NaPi-2) was investigated by expressing NaPi-2 in Xenopus laevis oocytes and applying the two-electrode voltage clamp. In the steady state, superfusion with inorganic phosphate (Pi) induced inward currents (Ip) in the presence of 96 mM Na+ over the potential range −140 ≤ V ≤ +40 mV. With Pi as the variable substrate, the apparent affinity constant (K
m
Pi) was strongly dependent on Na+, increasing sixfold for a twofold reduction in external Na+. K
m
Pi increased with depolarizing voltage and was more sensitive to voltage at reduced Na+. The Hill coefficient was close to unity and the predicted maximum Ip (Ipmax) was 40% smaller at 50 mM Na+. With Na+ as the variable substrate, K
m
Na was weakly dependent on both Pi and voltage, the Hill coefficient was close to 3 and Ipmax was independent of Pi at −50 mV. The competitive inhibitor phosphonoformic acid suppressed the steady state holding current in a Na+-dependent manner, indicating the existence of uncoupled Na+ slippage. Voltage steps induced pre–steady state relaxations typical for Na+-coupled cotransporters. NaPi-2-dependent relaxations were quantitated by a single, voltage-dependent exponential. At 96 mM Na+, a Boltzmann function was fit to the steady state charge distribution (Q-V) to give a midpoint voltage (V0.5) in the range −20 to −50 mV and an apparent valency of ∼0.5 e−. V0.5 became more negative as Na+ was reduced. Pi suppressed relaxations in a dose-dependent manner, but had little effect on their voltage dependence. Reducing external pH shifted V0.5 to depolarizing potentials and suppressed relaxations in the absence of Na+, suggesting that protons interact with the unloaded carrier. These findings were incorporated into an ordered kinetic model whereby Na+ is the first and last substrate to bind, and the observed voltage dependence arises from the unloaded carrier and first Na+ binding step. 相似文献
108.
109.
Sebastian Michael Olaf Kelber Sunna Hauschildt Katharina Spanel-Borowski Karen Nieber 《Phytomedicine》2009,16(2-3):161-171
Inflammation is a common mechanism of many gastrointestinal diseases. Therefore, it is interesting to know, whether complex phytopharmaceuticals known to modulate gastrointestinal motor function reveal also anti-inflammatory properties. We tested the fixed herbal combination product STW 5 (Iberogast®) and its main component Iberis amara fresh plant extract (STW 6) to characterize their protective potential in an experimental inflammation model in vitro. The test system consisted of ileum/jejunum segments from male Wistar rats. Inflammation was evoked by intraluminal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) for 30 min. Preincubation of TNBS together with STW 5 and STW 6 prevented the TNBS-induced inhibition of ACh-induced contractions. No differences were found between water-dissolved and ethanol-dissolved extracts. STW 5 and STW 6 reduced morphological changes induced by TNBS in mucosal and muscle layers. The IL-10 mRNA measured by qRT-PCR was not influenced by TNBS but increased by STW 5 and STW 6. The TNBS-induced increase in the TNFα-mRNA expression was suppressed by STW 5 but not by STW 6. Additionally, STW 5 decreased TNFα release in LPS-stimulated human monocytes. STW 6 influenced neither the TNFα-mRNA nor the TNFα release. These findings demonstrate that STW 5 reduced inflammation-induced alterations in ileum/jejunum segments. The effects were associated with a restoration of the disturbed ACh-induced contraction, pathohistological protection and inhibition of TNFα. STW 6 may contribute to the protective effect of STW 5 mainly by increasing IL-10 pathway but not by influencing TNFα. 相似文献
110.
Ricarda Jahnel Olaf Bender Lisa M Münter Mathias Dreger Clemens Gillen Ferdinand Hucho 《European journal of biochemistry》2003,270(21):4264-4271
The vanilloid-like TRP-channel VRL-1 (TRPV2) is a nonselective cation channel expressed by primary sensory neurons and non-neuronal tissues [Caterina, M.J., Rosen, T.A., Tominaga, M., Brake, A.J and Julius, D. (1999) Nature 398, 436-441]. It is one of the six members of the vanilloid-like TRP-channel family which is now termed the TRPV family [Montell, G., Birnbaumer, L., Flockerzi, V., Bindels, R.J., Brutford, E.A., Caterina, M.J., Clapham, D.E., Harteneck, C., Heller, S., Julius, D., Kojima, I., Mori, Y., Penner, R., Prawitt, D., Scharenberg, A.M., Schultz, G., Shimizu, N. and Zhu, M.X. (2002) Mol. Cell 2, 229-231]. As it is a temperature-gated channel, VRL-1 appears to be functionally related to VR1. In contrast to VR1, VRL-1 is activated at a higher temperature threshold and it does not respond to capsaicin or protons. Here we describe the expression of VRL-1 in the rat dorsal root ganglion-derived cell line F-11, a hybridoma of mouse neuroblastoma (N18TG2) and rat dorsal root ganglion cells. We found by RT-PCR that F-11 cells express not only the rat VRL-1, but also its mouse orthologue in a single cell. The F-11 parental cell line N18TG2 also expressed murine VRL-1. Due to its neuronal character, the DRG-derived F-11 cell line provides an experimental system for the study of VRL-1 biochemistry. However, one has to be aware that both the mouse and the rat protein are expressed simultaneously. Furthermore we cloned VRL-1 from rat brain and analyzed its glycosylation and localization in comparison to the endogenously expressed protein in F-11 cells. In contrast to the endogenous VRL-1 the overexpressed protein is glycosylated. Similar to VR1 the glycosylation is N-linked as shown by an deglycosylation assay. Immunofluorescence analysis of the endogenous VRL-1 in F-11 cells gives only weak signals in the cytoplasm whereas the overexpressed rat VRL-1 appears mainly at the plasma membrane. 相似文献