scholarly journals A Novel Bradykinin-Related Peptide, RVA-Thr6-BK, from the Skin Secretion of the Hejiang Frog; Ordorrana hejiangensis: Effects of Mammalian Isolated Smooth Muscle

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 376 ◽  
Author(s):  
Yue Wu ◽  
Daning Shi ◽  
Xiaoling Chen ◽  
Lei Wang ◽  
Yuan Ying ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Single Site ◽  
Skin Secretion ◽  
Rat Uterus ◽  
Rat Ileum ◽  
Related Peptide ◽  
Naturally Occurring ◽  
N Terminus ◽  
The Difference

A novel naturally-occurring bradykinin-related peptide (BRP) with an N-terminal extension, named RVA-Thr6-Bradykinin (RVA-Thr6-BK), was here isolated and identified from the cutaneous secretion of Odorrana hejiangensis (O. hejiangensis). Thereafter, in order to evaluate the difference in myotropic actions, a leucine site-substitution variant from Amolops wuyiensis skin secretion, RVA-Leu1, Thr6-BK, was chemically synthesized. Myotropic studies indicated that single-site arginine (R) replacement by leucine (L) at position-4 from the N-terminus, altered the action of RVA-Thr6-BK from an agonist to an antagonist of BK actions on rat ileum smooth muscle. Additionally, both BK N-terminal extended derivatives (RVA-Thr6-BK and RVA-Leu1, Thr6-BK) exerted identical myotropic actions to BK, such as increasing the frequency of contraction, contracting and relaxing the rat uterus, bladder and artery preparations, respectively.

scholarly journals Carbon Isotope Fractionation during the Formation of CO2 Hydrate and Equilibrium Pressures of 12CO2 and 13CO2 Hydrates

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4215
Author(s):  
Hiromi Kimura ◽  
Go Fuseya ◽  
Satoshi Takeya ◽  
Akihiro Hachikubo
Keyword(s):  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Small Difference ◽  
Hydrate Formation ◽  
Formation Temperature ◽  
Carbon Isotope Fractionation ◽  
Unit Cell Size ◽  
Naturally Occurring ◽  
Three Phase ◽  
The Difference

Knowledge of carbon isotope fractionation is needed in order to discuss the formation and dissociation of naturally occurring CO2 hydrates. We investigated carbon isotope fractionation during CO2 hydrate formation and measured the three-phase equilibria of 12CO2–H2O and 13CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12CO2 and 13CO2 was revealed, although their unit cell size was similar. The δ13C of hydrate-bound CO2 was lower than that of the residual CO2 (1.0–1.5‰) in a formation temperature ranging between 226 K and 278 K. The results show that the small difference between equilibrium pressures of ~0.01 MPa in 12CO2 and 13CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the difference between equilibrium pressures in the 12CO2–H2O and 13CO2–H2O systems was smaller than the standard uncertainties of measurement; more accurate pressure measurement is required for quantitative discussion.

scholarly journals Comparisons of the effects of tamoxifen, toremifene and raloxifene on enzyme induction and gene expression in the ovariectomised rat uterus

2001 ◽  
Vol 170 (3) ◽  
pp. 555-564 ◽  
Author(s):  
AR Green ◽  
EL Parrott ◽  
M Butterworth ◽  
PS Jones ◽  
P Greaves ◽  
...  
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Rt Pcr ◽  
Biphasic Response ◽  
Down Regulation ◽  
Rat Uterus ◽  
Carcinogenic Effects ◽  
The Difference ◽  
Er Alpha ◽  
Ovariectomised Rats

This study compares the actions of oestradiol, tamoxifen, toremifene and raloxifene on enzyme and gene expression in uterine tissues of ovariectomised rats over 72 h. The time-course for the induction of ornithine decarboxylase by the compounds showed a rapid biphasic response, while for creatine kinase brain type (BB) there was a continued increase over 72 h. The efficacy of induction showed that, with both markers, oestradiol gave the highest induction level, followed by tamoxifen or toremifene and then raloxifene. RT-PCR demonstrated that all compounds decreased oestrogen receptor (ER) alpha, ERbeta and ERbeta2 gene expression, 8-24 h after the first dose, suggesting that down-regulation of ER is not the primary cause of the difference in efficacy between these compounds. Using cDNA arrays, expression of 512 genes was examined in the uteri of oestradiol- or tamoxifen-treated rats. Both compounds resulted in the up-regulation of heat-shock protein 27, telomerase-associated protein 1 and secretin. However, most surprising was the marked down-regulation of Wilms' tumour and retinoblastoma genes. We speculate that this may result in a loss of regulation of the transition from the G1 to the S phase in the cell cycle and may make cells more vulnerable to the carcinogenic effects of tamoxifen in this tissue.

scholarly journals N-terminal pyroglutamate formation in CX3CL1 is essential for its full biologic activity

2017 ◽  
Vol 37 (4) ◽  
Author(s):  
Astrid Kehlen ◽  
Monique Haegele ◽  
Livia Böhme ◽  
Holger Cynis ◽  
Torsten Hoffmann ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Smooth Muscle Cells ◽  
Adhesion Molecule ◽  
Muscle Cells ◽  
Mitogen Activated Protein Kinase ◽  
Intercellular Adhesion Molecule ◽  
Dependent Manner ◽  
Glutaminyl Cyclase ◽  
N Terminus

CX3CL1 (fractalkine) is a unique member of the CX3C chemokine family and mediates both adhesion and cell migration in inflammatory processes. Frequently, the activity of chemokines depends on a modified N-terminus as described for the N-terminus of CCL2 modified to a pGlu- (pyroglutamate) residue by QC (glutaminyl cyclase) activity. Here, we assess the role of the pGlu-modified residue of the CX3CL1 chemokine domain in human endothelial and smooth muscle cells. For the first time, we demonstrated using MS that QC (QPCT, gene name of QC) or its isoenzyme isoQC (iso-glutaminyl cyclase) (QPCTL, gene name of isoQC) catalyse the formation of N-terminal-modified pGlu-CX3CL1. Expression of QPCT is co-regulated with its substrates CCL2 and CX3CL1 in HUVECs (human umbilical vein endothelial cells) and HCASMCs (human coronary artery smooth muscle cells) upon stimulation with TNF-α and IL-1β whereas QPCTL expression is not affected. By contrast, inhibition of the NF-κB pathway using an IKK2 inhibitor decreased the expression of the co-regulated targets QPCT, CCL2, and CX3CL1. Furthermore, RNAi-mediated inhibition of QPCT expression resulted in a reduction in CCL2 and CX3CL1 mRNA. In HCASMCs, N-terminal-modified pGlu1-CX3CL1 induced a significant stronger effect on phosphorylation of ERK (extracellular signal regulated kinase) 1/2, Akt (protein kinase B), and p38 (p38 mitogen-activated protein kinase) kinases than the immature Gln1-CX3CL1 in a time- and concentration-dependent manner. Furthermore, pGlu1-CX3CL1 affected the expression of CCL2, CX3CL1, and the adhesion molecule ICAM1/CD54 (intercellular adhesion molecule-1) inducing in higher expression level compared with its Gln1-variant in both HCASMCs and HUVECs. These results strongly suggest that QC-catalysed N-terminal pGlu formation of CX3CL1 is important for the stability or the interaction with its receptor and opens new insights into the function of QC in inflammation.

Ovarian hormones and resting potential of rabbit uterine smooth muscle

1964 ◽  
Vol 207 (4) ◽  
pp. 793-799 ◽  
Author(s):  
C. Y. Kao ◽  
A. Nishiyama
Keyword(s):  
Smooth Muscle ◽  
Distribution Pattern ◽  
Ovarian Hormones ◽  
Resting Potential ◽  
Glass Capillary ◽  
Active Uptake ◽  
Uterine Smooth Muscle ◽  
The Difference ◽  
Complex Distribution ◽  
Chloride Concentrations

Myometrial strips isolated from uterus of rabbits under either estrogen or progesterone domination were impaled with glass capillary microelectrodes for measurement of resting potential. This was found to be 49.81 ± 0.34 mv for estrogen-dominated myometrium (mean ±se of 616 samples), and 48.86 ± 0.43 mv for progesterone-dominated myometrium (514 samples), the difference between the resting potentials being insignificant. Therefore, the validity of the so-called "progesterone-block" hypothesis is questioned. Collagen was present in 14 g/kg of wet tissue in both hormonal states. These amounts did not hold sufficient chloride to appreciably lower the intracellular chloride concentrations, which were high enough to suggest either a complex distribution pattern or some active uptake for chloride. The relative cation permeabilities (Pna/Pk) were estimated as 0.11 for the estrogen-dominated myometrium, and 0.17 for the progesterone-dominated myometrium.

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