Browsing by Subject "Vasoconstriction"

Now showing 1 - 6 of 6
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    Agonist antibody to guanylate cyclase receptor NPR1 regulates vascular tone
    (Springer Nature, 2024) Dunn, Michael E.; Kithcart, Aaron; Kim, Jee Hae; Ho, Andre Jo-Hao; Franklin, Matthew C.; Romero Hernandez, Annabel; de Hoon, Jan; Botermans, Wouter; Meyer, Jonathan; Jin, Ximei; Zhang, Dongqin; Torello, Justin; Jasewicz, Daniel; Kamat, Vishal; Garnova, Elena; Liu, Nina; Rosconi, Michael; Pan, Hao; Karnik, Satyajit; Burczynski, Michael E.; Zheng, Wenjun; Rafique, Ashique; Nielsen, Jonas B.; De, Tanima; Verweij, Niek; Pandit, Anita; Locke, Adam; Chalasani, Naga; Melander, Olle; Schwantes-An, Tae-Hwi; Penn Medicine Biobank; Baras, Aris; Lotta, Luca A.; Musser, Bret J.; Mastaitis, Jason; Devalaraja-Narashimha, Kishor B.; Rankin, Andrew J.; Huang, Tammy; Herman, Gary; Olson, William; Murphy, Andrew J.; Yancopoulos, George D.; Olenchock, Benjamin A.; Morton, Lori; Medicine, School of Medicine
    Heart failure is a leading cause of morbidity and mortality1,2. Elevated intracardiac pressures and myocyte stretch in heart failure trigger the release of counter-regulatory natriuretic peptides, which act through their receptor (NPR1) to affect vasodilation, diuresis and natriuresis, lowering venous pressures and relieving venous congestion3-8. Recombinant natriuretic peptide infusions were developed to treat heart failure but have been limited by a short duration of effect9,10. Here we report that in a human genetic analysis of over 700,000 individuals, lifelong exposure to coding variants of the NPR1 gene is associated with changes in blood pressure and risk of heart failure. We describe the development of REGN5381, an investigational monoclonal agonist antibody that targets the membrane-bound guanylate cyclase receptor NPR1. REGN5381, an allosteric agonist of NPR1, induces an active-like receptor conformation that results in haemodynamic effects preferentially on venous vasculature, including reductions in systolic blood pressure and venous pressure in animal models. In healthy human volunteers, REGN5381 produced the expected haemodynamic effects, reflecting reductions in venous pressures, without obvious changes in diuresis and natriuresis. These data support the development of REGN5381 for long-lasting and selective lowering of venous pressures that drive symptomatology in patients with heart failure.
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    Effects of skeletal unloading on the vasomotor properties of the rat femur principal nutrient artery
    (American Physiological Society, 2015-04-15) Prisby, Rhonda D.; Behnke, Bradley J.; Allen, Matthew R.; Delp, Michael D.; Department of Anatomy & Cell Biology, IU School of Medicine
    Spaceflight and prolonged bed rest induce deconditioning of the cardiovascular system and bone loss. Previous research has shown declines in femoral bone and marrow perfusion during unloading and with subsequent reloading in hindlimb-unloaded (HU) rats, an animal model of chronic disuse. We hypothesized that the attenuated bone and marrow perfusion may result from altered vasomotor properties of the bone resistance vasculature. Therefore, the purpose of this study was to determine the effects of unloading on the vasoconstrictor and vasodilator properties of the femoral principal nutrient artery (PNA), the main conduit for blood flow to the femur, in 2 wk HU and control (CON) rats. Vasoconstriction of the femoral PNA was assessed in vitro using norepinephrine, phenylephrine, clonidine, KCl, endothelin-1, arginine vasopressin, and myogenic responsiveness. Vasodilation through endothelium-dependent [acetylcholine, bradykinin, and flow-mediated dilation (FMD)] and endothelium-independent mechanisms [sodium nitroprusside (SNP) and adenosine] were also determined. Vasoconstrictor responsiveness of the PNA from HU rats was not enhanced through any of the mechanisms tested. Endothelium-dependent vasodilation to acetylcholine (CON, 86 ± 3%; HU, 48 ± 7% vasodilation) and FMD (CON, 61 ± 9%; HU, 11 ± 11% vasodilation) were attenuated in PNAs from HU rats, while responses to bradykinin were not different between groups. Endothelium-independent vasodilation to SNP and adenosine were not different between groups. These data indicate that unloading-induced decrements in bone and marrow perfusion and increases in vascular resistance are not the result of enhanced vasoconstrictor responsiveness of the bone resistance arteries but are associated with reductions in endothelium-dependent vasodilation.
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    How Can We Make BOLD Contrast Bolder?
    (American Society of Neuroradiology, 2002-04) Li, Tie Qiang; Mathews, Vincent P.; Radiology and Imaging Sciences, School of Medicine
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    Percutaneous Renal Access: Surgical Factors Involved in the Acute Reduction of Renal Function
    (Mary Ann Liebert, Inc., 2016-02) Handa, Rajash K.; Johnson, Cynthia D.; Connors, Bret A.; Evan, Andrew P.; Lingeman, James E.; Liu, Ziyue; Department of Anatomy & Cell Biology, IU School of Medicine
    INTRODUCTION AND OBJECTIVE: Studies in patients and experimental animals have shown that percutaneous nephrolithotomy (PCNL) can acutely impair glomerular filtration and renal perfusion, but the factors contributing to this decline in renal function are unknown. The present study assessed the contribution of needle puncture of the kidney vs dilation of the needle tract to the acute decline in renal hemodynamic and tubular transport function associated with PCNL surgery. MATERIALS AND METHODS: Acute experiments were performed in three groups of anesthetized adult farm pigs: sham-percutaneous access (PERC), that is, no surgical procedure (n = 7); a single-needle stick to access the renal collecting system (n = 8); expansion of the single-needle access tract with a 30F NephroMax balloon dilator and insertion of a nephrostomy sheath (n = 10). The glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and renal extraction of para-amino hippurate (EPAH, estimates tubular organic anion transporter [OAT] activity) were assessed before and 1 to 4.5 hours after sham-PERC or PERC surgical procedures. RESULTS: Overall, GFR responses were similar in all three groups. Sham-treated PERC pigs showed no significant change in ERPF over the experimental observation period, whereas a single-needle stick to access the renal collecting system resulted in renal vasoconstriction (∼30% reduction in ERPF, p < 0.05). Dilation of the single-needle access tract to create the nephrostomy did not lead to a further decline in ERPF. PERC surgical procedure-mediated renal vasoconstriction was most evident at the 1-hour posttreatment time point. A reduction in EPAH was only observed in pig kidneys with a nephrostomy. CONCLUSIONS: Needle puncture of the kidney for percutaneous access to the renal collecting system is the major driving force for the renal vasoconstriction observed after PCNL surgery, whereas creation of the nephrostomy appears to be largely responsible for decreasing tubular OAT activity.
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    Perivascular Adipose Tissue Potentiates Contraction of Coronary Vascular Smooth Muscle: Influence of Obesity
    (American Heart Association, 2013) Owen, Meredith Kohr; Witzmann, Frank A.; McKenney, Mikaela L.; Lai, Xianyin; Berwick, Zachary C.; Moberly, Steven P.; Alloosh, Mouhamad; Sturek, Michael; Tune, Johnathan D.; Cellular and Integrative Physiology, School of Medicine
    Background: This investigation examined the mechanisms by which coronary perivascular adipose tissue (PVAT)-derived factors influence vasomotor tone and the PVAT proteome in lean versus obese swine. Methods and results: Coronary arteries from Ossabaw swine were isolated for isometric tension studies. We found that coronary (P=0.03) and mesenteric (P=0.04) but not subcutaneous adipose tissue augmented coronary contractions to KCl (20 mmol/L). Inhibition of CaV1.2 channels with nifedipine (0.1 µmol/L) or diltiazem (10 µmol/L) abolished this effect. Coronary PVAT increased baseline tension and potentiated constriction of isolated arteries to prostaglandin F2α in proportion to the amount of PVAT present (0.1-1.0 g). These effects were elevated in tissues obtained from obese swine and were observed in intact and endothelium denuded arteries. Coronary PVAT also diminished H2O2-mediated vasodilation in lean and, to a lesser extent, in obese arteries. These effects were associated with alterations in the obese coronary PVAT proteome (detected 186 alterations) and elevated voltage-dependent increases in intracellular [Ca(2+)] in obese smooth muscle cells. Further studies revealed that the Rho-kinase inhibitor fasudil (1 µmol/L) significantly blunted artery contractions to KCl and PVAT in lean but not obese swine. Calpastatin (10 μmol/L) also augmented contractions to levels similar to that observed in the presence of PVAT. Conclusions: Vascular effects of PVAT vary according to anatomic location and are influenced by an obese phenotype. Augmented contractile effects of obese coronary PVAT are related to alterations in the PVAT proteome (eg, calpastatin), Rho-dependent signaling, and the functional contribution of K(+) and CaV1.2 channels to smooth muscle tone.
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