In vitro tracheal responses from mice chosen for in vivo lung cholinergic sensitivity

1990 ◽  
Vol 69 (1) ◽  
pp. 274-280 ◽  
Author(s):  
G. G. Weinmann ◽  
C. M. Black ◽  
R. C. Levitt ◽  
C. A. Hirshman
Keyword(s):  
Linear Regression Analysis ◽  
Inbred Strains ◽  
Multiple Linear Regression Analysis ◽  
Maximal Response ◽  
Inbred Strains Of Mice ◽  
Cholinergic Agents ◽  
Cholinergic Sensitivity

We selected two inbred strains of mice based on their different in vivo lung responses to intravenous acetylcholine for studies on the in vitro tracheal responses to contractile and relaxing agents. In addition, we studied the role of cyclooxygenase products on the in vitro responses. Tracheal rings were contracted with increasing concentrations of carbachol and KCl and relaxed with increasing concentrations of isoproterenol after contraction with carbachol at the concentration that produced 30, 50, and 70% of the maximal contraction (EC30, EC50, and EC70, respectively) and KCl at the EC50. Half the tracheae simultaneously underwent the same protocols after pretreatment with indomethacin (3 X 10(-6) M). Despite a severalfold difference in the maximal response to cholinergic agents in vivo, there were no significant differences between the strains in the tracheal responses to carbachol (P = 0.78) or KCl (P = 0.13) in vitro. Both strains showed inhibition of the isoproterenol relaxation by carbachol (P less than 0.0001). Multiple linear regression analysis showed that the strain that was more sensitive to carbachol in vivo was also more sensitive to isoproterenol in vitro after carbachol contraction (P = 0.014). The greater isoproterenol sensitivity of the tracheae from this strain was not present after contraction with KCl, nor were these tracheae more sensitive to relaxation with sodium nitroprusside. Indomethacin pretreatment of the tissues in vitro augmented the maximal response and the sensitivity to carbachol (P less than 0.001) and KCl (P = 0.0006), and this effect was similar in both strains. Evaluation of isoproterenol relaxation after indomethacin pretreatment was confounded by the lower concentrations of carbachol needed for contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Enhancement of coxsackievirus B3 infection by antibody to a different coxsackievirus strain

2002 ◽  
Vol 83 (2) ◽  
pp. 351-358 ◽  
Author(s):  
Jaskamal Girn ◽  
Mojgan Kavoosi ◽  
Janet Chantler
Keyword(s):  
Viral Myocarditis ◽  
Neutralizing Antibody ◽  
Inbred Strains ◽  
Inbred Strains Of Mice ◽  
Infected Cells ◽  
Group B ◽  
Multiple Strains ◽  
Old Mice

Group B coxsackieviruses (CVBs) are a major cause of viral myocarditis and pancreatitis in humans and produce a similar pattern of disease in inbred strains of mice. As there are six strains of CVBs, individuals can be infected with multiple serotypes. This raises the possibility of antibody enhancement of infectivity (AEI) by cross-reactive but non-neutralizing antibody to a different strain from a prior infection. To determine whether AEI plays a role in coxsackievirus pathogenesis, an in vitro system using the murine macrophage cell line J774.1 was tested for enhanced infection when incubated with CVB3 plus anti-CVB2 antibody. Yields of virus were found to increase by 10–50-fold and the percentage of infected cells increased proportionately. The effect was Fc-mediated as F(ab′)2 fragments of the antibody could not mediate the effect. To determine whether AEI could also be demonstrated in vivo CVB3 was injected into 5-week-old mice together with mouse polyclonal anti-CVB2. Controls included mice injected with PBS or CVB3 alone. Results showed that the titres of virus in tissues of animals injected with virus plus antibody were 1–2 logs higher than when virus was injected alone. This was accompanied by greater histopathological damage, particularly in the heart. These results have implications for human disease as infection with multiple strains likely occurs during the lifetime of an individual.

scholarly journals Renal miR-148b is associated with megalin down-regulation in IgA nephropathy

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Lu Wen ◽  
Zhanzheng Zhao ◽  
Jing Xiao ◽  
Zheng Wang ◽  
Xiangfei He ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Mrna Expression ◽  
Iga Nephropathy ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Mrna Levels ◽  
Immunofluorescence Labeling ◽  
Normal Controls

Megalin is essential for proximal tubule reabsorption of filtered proteins, hormones, and vitamins, and its dysfunction has been reported in IgA nephropathy (IgAN). miR-148b has been shown to regulate renal megalin expression in vitro and in animal models of kidney disease. We examined a potential role of miR-148b and other miRNAs in regulating megalin expression in IgAN by analyzing the association between megalin and miR-148b, miR-21, miR-146a, and miR-192 expression. Quantitative PCR (qPCR) analysis identified a marked increase in renal levels of several miRNAs, including miR-148b, miR-21, miR-146a, and a significant decrease in megalin mRNA levels in IgAN patients when compared with normal controls. By multiple linear regression analysis, however, only renal miR-148b was independently associated with megalin mRNA levels in IgAN. Proximal tubule megalin expression was further evaluated by immunofluorescence labeling of biopsies from the patients. The megalin expression was significantly lower in patients with highest levels of renal miR-148b compared with patients with lowest levels. To examine the direct effects of the miRNAs on megalin and other membrane proteins expression, proximal tubule LLC-PK1 cells were transfected with miR-148b, miR-21, miR-146a, or miR-192 mimics. Transfection with miR-148b mimic, but not the other three miRNA mimics inhibited endogenous megalin mRNA expression. No significant effect of any of the four miRNA mimics was observed on cubilin or aquaporin 1 (AQP1) mRNA expression. The findings suggest that miR-148b negatively regulates megalin expression in IgAN, which may affect renal uptake and metabolism of essential substances.

Abstract 066: Regulation of Nephron Afferent Arteriole Resistance in Obesity: Role of Insulin and Connecting Tubule Glomerular Feedback

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Sumit R Monu ◽  
Yilin Ren ◽  
Mani Maheshwari ◽  
Ed Peterson ◽  
Oscar A Carretero
Keyword(s):  
Renal Damage ◽  
Maximal Response ◽  
Nacl Transport ◽  
Connecting Tubule ◽  
Renal Micropuncture ◽  
Flow Pressure ◽  
Epithelial Sodium Channel Enac

Introduction: In obesity, increased glomerular capillary pressure (P GC ) may participate in renal damage.P GC is controlled in part by afferent arteriolar ( Af-Art ) resistance that in turn is regulated by two renal intrinsic feedback mechanisms, the vasoconstrictor Tubulo-Glomerular Feedback (TGF), and vasodilator Connecting Tubule Glomerular Feedback (CTGF). CTGF is initiated by an increase in NaCl transport by the epithelial sodium channel (ENaC) in the connecting tubule (CNT). Interestingly, obesity is strongly associated with hyperinsulinemia and insulin is a potent ENaC activator. Hypothesis: In obesity, hyperinsulinemia increases CTGF via activation of the ENaC, this increase, in turn, contributes to TGF attenuation leading to increased P GC and renal damage. Methods: In vivo : In zucker obese rats (ZOR) and zucker lean rats (ZLR), we measured TGF and CTGF using renal micropuncture at 9-10 weeks of age. We quantify stop-flow pressure (P SF ) as an index of P GC . We measured proteinuria as a marker of renal damage in both ZOR and ZLR. In vitro: Microdissected rabbit Af-Arts and their adherent CNTs were perfused with NaCl, insulin or ENaC inhibitor (Benzamil; BZ) to investigate the role of insulin on TGF and CTGF. Results: In-vivo : Maximal TGF response was significantly less in ZOR (6.11 ± 0.75 mmHg) in comparison to the ZLR (9.5 ± 1.1 mmHg, p<0.05). CTGF inhibition by BZ normalized the TGF response in ZOR similar to ZLR (ZOR, 14.01±1.70 mmHg vs ZLR, 11.46± 2.25 mmHg) suggesting CTGF playing a key role in TGF resetting in ZOR. Additionally, ZOR develops proteinuria (mg/24h) at 12 weeks of age (ZOR; 24.85±3.02 vs ZLR; 7.21±1.09, p<0.05 ). In-vitro microperfusion of NaCl in the CNT that elicited a half-maximal response (EC 50 , mmol/L) of Af-Art dilation was 25.0±0.8; an addition of insulin 10 -7 mol/l to the CNT lumen decreased the EC 50 to 8.1±0.8 ( P <0.05) suggesting insulin potentiates CTGF. BZ blocked the insulin-mediated CTGF (Insulin EC 50 : 7.8±0.9 vs . Insulin+BZ, EC 50 : 19.7±5.5; P <0.05). Conclusion: In-vivo : TGF is reset in ZOR due to enhanced CTGF before they develop proteinuria. In-vitro : Insulin increased CTGF during microperfusion experiments. Perspective: Insulin-induced increased in CTGF may explain higher P GC and renal damage in obesity.

In vivo and in vitro glycogenic effects of methionine sulfoximine are different in two inbred strains of mice

2002 ◽  
Vol 929 (2) ◽  
pp. 147-155 ◽  
Author(s):  
Katy Bernard-Hélary ◽  
Marie-Yvonne Ardourel ◽  
Tobias Hévor ◽  
Jean-François Cloix
Keyword(s):  
Inbred Strains ◽  
Methionine Sulfoximine ◽  
Inbred Strains Of Mice

Cholinergic responsiveness of respiratory and vascular tissues in two different rat strains

1988 ◽  
Vol 64 (1) ◽  
pp. 323-328 ◽  
Author(s):  
M. Badier ◽  
M. Soler ◽  
M. Mallea ◽  
S. Delpierre ◽  
J. Orehek
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Dose Response ◽  
Response Curve ◽  
Dose Response Curve ◽  
Maximal Response ◽  
Arterial Smooth Muscle ◽  
Cholinergic Agents

The airway and systemic arterial smooth muscle responsiveness to cholinergic agents of two strains of rats, Rat Albino (RA) and Brown Norway (BN), was compared in vivo and in vitro. In vivo, we measured the doses of carbachol that induced a 100% increase in lung resistance (PD100 RL), a 50% decrease in dynamic lung compliance (PD50 Cdyn), and the value of systolic blood pressure at the carbachol dose of 10 micrograms (Pa 10 micrograms). In vitro airway smooth muscle and systemic arterial smooth muscle responsiveness was assessed by measuring the maximal response to acetylcholine, the slope of the linear portion of the dose-response curve, and the negative logarithm of the molar concentration of acetylcholine producing 50% of the maximal response (pD2). PD100 and PD50 were about four times greater in BN rats than in RA rats. In contrast, Pa 10 micrograms was 1.5 lower in the BN rats. These differences persisted after bivagotomy. Tracheal pD2 was 25% greater in the RA than in the BN strain. The mean dose-response curve of parenchymal strips of RA rats was situated upward and to the left of the BN curve, but the reverse was observed for aortic smooth muscle dose-response curves. Thus 1) airway smooth muscle responsiveness to cholinergic agents is greater in RA strain than in BN, but the reverse is true for systemic arterial smooth muscle responsiveness; and 2) these differences are not due to factors extrinsic to the smooth muscle, since they occurred in vitro and may depend on different densities of muscarinic receptors.

Strain difference in the timing of meiosis resumption in mouse oocytes: involvement of a cytoplasmic factor(s) acting presumably upstream of the dephosphorylation of p34cdc2 kinase

Zygote ◽  
1997 ◽  
Vol 5 (2) ◽  
pp. 105-109 ◽  
Author(s):  
Zbigniew Polanński
Keyword(s):  
Extreme Values ◽  
Strain Difference ◽  
Germinal Vesicle ◽  
Inbred Strains ◽  
Germinal Vesicle Breakdown ◽  
Cytoplasmic Factor ◽  
Inbred Strains Of Mice ◽  
The Difference

SummaryOocytes from eight inbred strains of mice were screened for the timing of germinal vesicle breakdown (GVB) in vitro. This characteristic varied between strains, reaching most extreme values in oocytes from AKR and BALB/c mice (3.1 and 1.6h after release from dibutyryl cAMP block, respectively; p<0.0001). The difference between AKR and BALB/c mice was confirmed in experiments in which GVB was induced in vivo by stimulation with exogenous gonadotrophins. Analysis of the rate of GVB in hybrids obtained after fusion of nuclear and cytoplamic fragments of oocytes from both strains suggests that the factor responsible for the difference between AKR and BALB/c mice is located in the cytoplasm of the proghase oocytes. Finally, in oocytes from both strains stimulated to resume meiotic maturation with okadaic acid, an inhibitor of protein phosphatases types 1 and 2A the rate of GVB was the same (2.2h and 2.3h for AKR and BALB/c, respectively; p= 0.48). This suggests that the difference between strains is not related to the amount or quality of the pre-MPF (Maturation Promoting Factor) stored in the prophase oocyte, but to the factor(s) acting upstream of the dephosphorylation of p34cdc2. kinase in the pathway leading to pre-MPF activation.

scholarly journals Exclusive involvement of H-2D(b) or H-2K(d) product in the interaction between T-killer lymphocytes and syngeneic H-2(b) or H-2(d) viral lymphomas

1977 ◽  
Vol 146 (4) ◽  
pp. 909-922 ◽  
Author(s):  
E Gomard ◽  
V Duprez ◽  
T Reme ◽  
MJ Colombani ◽  
JP Levy
Keyword(s):  
Inbred Strains ◽  
Antigenic Specificity ◽  
Target Cells ◽  
Chromium Release ◽  
Viral Budding ◽  
Inbred Strains Of Mice ◽  
Murine Sarcoma Virus ◽  
Specific Association

It was demonstrated previously that the cytolysis of murine viral lymphoma cells by anti-murine sarcoma virus (MSV) syngeneic T-killer lymphocytes was restricted by some products of the H-2 complex. The respective role of the products of different regions of the H-2 complex were studied with six H-2(b) and three H-2(d) lymphomas induced by five different type C viruses. They were tested in a classical chromium release test against anti-MSV T-killer cells obtained from different inbred strains of mice, including several H-2 recombinants. Tumors o£ the H-2(b) haplotype were lysed only when effectors and target cells have in common the D(b) region. On the contrary an identity limited to the K end of the H-2 complex is necessary and sufficient in the H-2(d) haplotype. An in vitro restimulation of the spleen cells with concanavalin A strongly increased the activity of in vivo-primed T lymphocytes but did not provide any response for in vivo-primed but nonresponder cells. Preincubation of the tumor cells with anti-H-2 sera abolished the lysis by syngeneic anti-MSV effector lymphocytes. The same results were obtained by preincubating the H-2(b) targets with anti-H-2D(b), or the H-2(d) target with anti-H-2K(d). Preincubation with anti-H-2K(b) or anti- H-2D(d) were ineffective. These results show that the T-killer/target cells interaction in the MSV system involved some products of the H-2 complex which might be different with the various H-2 haplotypes and could possibly vary according to the antigenic specificity. A specific association of a viral product with a normal cellular structure, directed by the H-2 region during the viral budding could explain the observed results.

scholarly journals Upregulation of MicroRNA 18b Contributes to the Development of Colorectal Cancer by Inhibiting CDKN2B

2017 ◽  
Vol 37 (22) ◽  
Author(s):  
Yiming Li ◽  
Meng Chen ◽  
Juan Liu ◽  
Lianyun Li ◽  
Xiao Yang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle Progression ◽  
Expression Profiles ◽  
Linear Regression Analysis ◽  
Ectopic Expression ◽  
Multiple Linear Regression Analysis ◽  
Luciferase Assay ◽  
Aberrant Expression

ABSTRACT MicroRNAs (miRNAs) exhibit aberrant expression in the initiation and progression of a variety of human cancers, including colorectal cancer (CRC). However, the exact mechanisms are not well defined. miRNA expression profiles were characterized by microarrays in CRC samples, and miRNA 18b (miR-18b) was increased significantly in tumor tissues. The expression of miR-18b was confirmed in the CRC cell lines SW480 and HCT116 and 44 clinical specimens by quantitative real-time PCR (qRT-PCR). Multiple linear regression analysis showed a strong correlation of miR-18b expression with lymph node and distant metastasis. Overexpression of miR-18b promoted cell proliferation by facilitating cell cycle progression, and knockdown of miR-18b significantly suppressed migration in CRC cells. CDKN2B was identified as a target of miR-18b by high-throughput RNA sequencing and bioinformatics. After transfection with a miR-18b mimic, expression of CDKN2B was reduced significantly in CRC cells, and the effect was restored when a miR-18b inhibitor was transfected. A luciferase assay indicated miR-18b directly binds to the 3′ untranslated region (UTR) of CDKN2B. Expression of CDKN2B was downregulated in patient cancer tissues and negatively correlated with miR-18b. In a model of ectopic expression of miR-18b and CDKN2B, CDKN2B overexpression antagonized the effects of miR-18b in vitro and in vivo. The data show that miR-18b is involved in CRC carcinogenesis through targeting CDKN2B.

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