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Batista PR, de Alencar Silva A, Mikevely de Sena Bastos C, de Souza Borges A, Dias FJ, Ramon Dos Santos Pereira L, Tavares de Sousa Machado S, de Araújo Delmondes G, Kerntopf MR, Alencar de Menezes IR, Barbosa R. Vasorelaxant effect of (E,E)-farnesol in human umbilical vein ex vivo assays. Chem Biol Interact 2023; 386:110746. [PMID: 37816450 DOI: 10.1016/j.cbi.2023.110746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 09/01/2023] [Accepted: 09/22/2023] [Indexed: 10/12/2023]
Abstract
(E,E)-farnesol is a sesquiterpene acyclic alcohol produced by bacteria, protozoa, fungi, plants, and animals. The literature describes its applications in food, pharmaceutical, and cosmetic industries, and also in the pharmacological context with a vasorelaxant effect. However, its effects on human umbilical vessels remain poorly investigated. Thus, this study aims to investigate, in a new way, the vasorelaxant effect of (E,E)-farnesol in human umbilical veins (HUV) from healthy donors. Rings obtained from isolated HUV were suspended in an organ bath to record their isometric tension in different experimental sections. (E,E)-farnesol (1 μmol/L to 1 mmol/L) promoted vasorelaxant effect in venous preparations contracted by depolarization (KCl 60 mmol/L) or pharmacological agonism (5-HT 10 μmol/L), with EC50 values of 239.9 μmol/L and 424 μmol/L, respectively. In calcium-free solution, this effect was also observable. (E,E)-farnesol was able to suppress contractions evoked by CaCl2 and BaCl2 suggesting a blockade of voltage-dependent (especially L-type) calcium channels. The vasorelaxant efficacy and potency of (E,E)-farnesol were affected in the presence of tetraethylammonium (1 and 10 mmol/L), glibenclamide (10 μmol/L) and BaCl2 (1 mmol/L) indicating a possible involvement of potassium channels (BKCa, KATP and KIR) in this effect. Our data suggest that (E,E)-farnesol has a promising potential to be applicable as a vasodilator in hypertensive conditions in pregnancy that alter HUV reactivity.
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Affiliation(s)
- Paulo Ricardo Batista
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil; Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | - Andressa de Alencar Silva
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil; Higher Institute of Biomedical Sciences, State University of Ceará, Fortaleza, 60714-903, Ceará, Brazil.
| | - Carla Mikevely de Sena Bastos
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil; Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | - Alex de Souza Borges
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil; Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | - Francisco Junio Dias
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | - Luiz Ramon Dos Santos Pereira
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | - Sara Tavares de Sousa Machado
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | | | - Marta Regina Kerntopf
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
| | | | - Roseli Barbosa
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil; Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil.
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Batista PR, Silva ADA, de Sena Bastos CM, Rodrigues da Silva RE, Calixto GL, de Morais LP, Delmondes GDA, Kerntopf MR, de Menezes IRA, Barbosa R. Vasodilation promoted by ( E, E)-farnesol involving ion channels in human umbilical arteries. Heliyon 2023; 9:e17328. [PMID: 37441374 PMCID: PMC10333471 DOI: 10.1016/j.heliyon.2023.e17328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/10/2023] [Accepted: 06/14/2023] [Indexed: 07/15/2023] Open
Abstract
Background (E,E)-farnesol is a sesquiterpene alcohol derived from plants and animals that exhibits pharmacological properties in the cardiovascular system. However, its effects on human umbilical vessels remain unknown. Purpose Thus, this study aims to characterize the vasodilatory effect of (E,E)-farnesol in human umbilical arteries (HUA). Study design The tissue is obtained from pregnant women over 18 years of age, normotensive, and without prepartum complications. After collected, the tissue was segmented and dissected to remove Wharton's jelly and obtain the umbilical arteries segments. Methods HUA segments were isolated and sectioned into rings that were subjected to isometric tension recordings in an organ bath. Results (E,E)-farnesol (1 μmol/L to 1 mmol/L) promoted vasodilatory effect in HUA preparations, affecting basal tone, and inhibiting the electromechanical coupling induced by KCl 60 mmol/L with greater potency (EC50 225.3 μmol/L) than the pharmacomechanical coupling induced by 5-HT 10 μmol/L (EC50 363.5 μmol/L). In the absence of extracellular calcium, pharmacomechanical coupling was also abolished, and contractions induced by CaCl2 or BaCl2 were attenuated by (E,E)-farnesol indicating a possible direct inhibition of L-type VOCC as a mechanism of the vasodilatory effect. The vasodilator efficacy of (E,E)-farnesol on reduction of vasocontraction induced by the presence of tetraethylammonium (1 or 10 mmol/L), 4-aminopyridine (1 mmol/L) and glibenclamide (10 μmol/L) suggesting a possible influence of different potassium channels (BKCa, KV and KATP). Conclusion These results suggest that (E,E)-farnesol may be a promising pharmacological candidate for obstetric hypertensive disorders.
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Affiliation(s)
- Paulo Ricardo Batista
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
| | - Andressa de Alencar Silva
- Graduate Program in Physiological Sciences, Higher Institute of Biomedical Sciences, State University of Ceará, Fortaleza, 60714-903, Ceará, Brazil
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
| | - Carla Mikevely de Sena Bastos
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
| | - Renata Evaristo Rodrigues da Silva
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
| | - Gabriela Lucena Calixto
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
| | - Luís Pereira de Morais
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
- Biotechnology By the Northeastern Biotechnology Network (RENORBIO), State University of Ceará, Fortaleza, 60714-903, Ceará, Brazil
| | | | - Marta Regina Kerntopf
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
| | | | - Roseli Barbosa
- Biological Chemistry Department, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
- Biological Sciences Department, Physiopharmacology of Excitable Cells Laboratory, Pimenta Campus, Regional University of Cariri, Crato, 63105-000, Ceará, Brazil
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Gc JB, Szlenk CT, Diyaolu A, Obi P, Wei H, Shi X, Gibson KM, Natesan S, Roullet JB. Allosteric modulation of α1β3γ2 GABA A receptors by farnesol through the neurosteroid sites. Biophys J 2023; 122:849-867. [PMID: 36721367 PMCID: PMC10027449 DOI: 10.1016/j.bpj.2023.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/13/2022] [Accepted: 01/23/2023] [Indexed: 02/02/2023] Open
Abstract
In mammalian cells, all-trans farnesol, a 15-carbon isoprenol, is a product of the mevalonate pathway. It is the natural substrate of alcohol dehydrogenase and a substrate for CYP2E1, two enzymes implicated in ethanol metabolism. Studies have shown that farnesol is present in the human brain and inhibits voltage-gated Ca2+ channels at much lower concentrations than ethanol. Here we show that farnesol modulates the activity of γ-aminobutyric acid type A receptors (GABAARs), some of which also mediate the sedative activity of ethanol. Electrophysiology experiments performed in HEK cells expressing human α1β3γ2 or α6β3γ2 GABAARs revealed that farnesol increased chloride currents through positive allosteric modulation of these receptors and showed dependence on both the alcoholic functional group of farnesol and the length of the alkyl chain for activity. In silico studies using long-timescale unbiased all-atom molecular dynamics (MD) simulations of the human α1β3γ2 GABAA receptors revealed that farnesol modulates the channel by directly binding to the transmembrane neurosteroid-binding site, after partitioning into the surrounding membrane and reaching the receptor by lateral diffusion. Channel activation by farnesol was further characterized by several structural and dynamic variables, such as global twisting of the receptor's extracellular domain, tilting of the transmembrane M2 helices, radius, cross-sectional area, hydration status, and electrostatic potential of the channel pore. Our results expand the pharmacological activities of farnesol to yet another class of ion channels implicated in neurotransmission, thus providing a novel path for understanding and treatment of diseases involving GABAA receptor dysfunction.
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Affiliation(s)
- Jeevan B Gc
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Christopher T Szlenk
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Ayobami Diyaolu
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Peter Obi
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Haiyang Wei
- Eurofins Panlabs, Inc., St. Charles, Missouri
| | - Xutong Shi
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - K Michael Gibson
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Senthil Natesan
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.
| | - Jean-Baptiste Roullet
- College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington.
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Araújo Delmondes GD, Pereira Lopes MJ, Araújo IM, de Sousa Borges A, Batista PR, Melo Coutinho HD, Alencar de Menezes IR, Barbosa-Filho JM, Bezerra Felipe CF, Kerntopf MR. Possible mechanisms involved in the neuroprotective effect of Trans,trans-farnesol on pilocarpine-induced seizures in mice. Chem Biol Interact 2022; 365:110059. [PMID: 35931201 DOI: 10.1016/j.cbi.2022.110059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/24/2022] [Accepted: 07/13/2022] [Indexed: 11/18/2022]
Abstract
This study aimed to investigate, through in vivo and in vitro methodologies, the effect of acute trans,trans-farnesol (12.5, 25, 50 or 100 mg/kg, p.o.) administration on behavioral and neurochemical parameters associated with pilocarpine-induced epileptic seizure (300 mg/kg, i.p.) in mice. The initial results showed that the compound in question presents no anxiolytic-like or myorelaxant effects, despite reducing locomotor activity in the animals at all doses tested. In addition, the lowest dose increased the latency to onset of the first epileptic seizure, and the time to death. In addition to decreasing the mortality percentage in mice submitted to the pilocarpine model. In this same model, pretreatment with the lowest dose of the compound decreased the hippocampal concentrations of thiobarbituric acid and nitrite, and partially restored striatal concentrations of noradrenaline, dopamine, and serotonin. Taken together, the results suggest that trans,trans-farnesol presents a central depressant effect which contributes to its antiepileptic action which, in turn, seems to be mediated by the antagonism of muscarinic cholinergic receptors, reduction of oxidative stress. and modulation of noradrenaline, dopamine and serotonin concentrations in the central nervous system.
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Affiliation(s)
- Gyllyandeson de Araújo Delmondes
- Postgraduate Program in Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil; Natural Products Pharmacology Laboratory, Regional University of Cariri, Crato, CE, Brazil.
| | | | - Isaac Moura Araújo
- Postgraduate Program in Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil
| | - Alex de Sousa Borges
- Postgraduate Program in Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil
| | - Paulo Ricardo Batista
- Postgraduate Program in Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil
| | | | | | | | | | - Marta Regina Kerntopf
- Postgraduate Program in Biological Chemistry, Regional University of Cariri, Crato, CE, Brazil; Natural Products Pharmacology Laboratory, Regional University of Cariri, Crato, CE, Brazil
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Farnesol induces protection against murine CNS inflammatory demyelination and modifies gut microbiome. Clin Immunol 2022; 235:108766. [PMID: 34091018 PMCID: PMC8660955 DOI: 10.1016/j.clim.2021.108766] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/21/2021] [Accepted: 05/31/2021] [Indexed: 02/08/2023]
Abstract
Farnesol is a 15‑carbon organic isoprenol synthesized by plants and mammals with anti-oxidant, anti-inflammatory, and neuroprotective activities. We sought to determine whether farnesol treatment would result in protection against murine experimental autoimmune encephalomyelitis (EAE), a well-established model of multiple sclerosis (MS). We compared disease progression and severity in C57BL/6 mice treated orally with 100 mg/kg/day farnesol solubilized in corn oil to corn-oil treated and untreated EAE mice. Farnesol significantly delayed the onset of EAE (by ~2 days) and dramatically decreased disease severity (~80%) compared to controls. Disease protection by farnesol was associated with a significant reduction in spinal cord infiltration by monocytes-macrophages, dendritic cells, CD4+ T cells, and a significant change in gut microbiota composition, including a decrease in the Firmicutes:Bacteroidetes ratio. The study suggests FOL could protect MS patients against CNS inflammatory demyelination by partially modulating the gut microbiome composition.
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Effects of Hyperglycemia on Vascular Smooth Muscle Ca 2+ Signaling. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3691349. [PMID: 28713824 PMCID: PMC5497615 DOI: 10.1155/2017/3691349] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 05/24/2017] [Indexed: 12/25/2022]
Abstract
Diabetes is a complex disease that is characterized with hyperglycemia, dyslipidemia, and insulin resistance. These pathologies are associated with significant cardiovascular implications that affect both the macro- and microvasculature. It is therefore important to understand the effects of various pathologies associated with diabetes on the vasculature. Here we directly test the effects of hyperglycemia on vascular smooth muscle (VSM) Ca2+ signaling in an isolated in vitro system using the A7r5 rat aortic cell line as a model. We find that prolonged exposure of A7r5 cells to hyperglycemia (weeks) is associated with changes to Ca2+ signaling, including most prominently an inhibition of the passive ER Ca2+ leak and the sarcoplasmic reticulum Ca2+-ATPase (SERCA). To translate these findings to the in vivo condition, we used primary VSM cells from normal and diabetic subjects and find that only the inhibition of the ER Ca2+ leaks replicates in cells from diabetic donors. These results show that prolonged hyperglycemia in isolation alters the Ca2+ signaling machinery in VSM cells. However, these alterations are not readily translatable to the whole organism situation where alterations to the Ca2+ signaling machinery are different.
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Affiliation(s)
- Deborah A Hogan
- Department of Microbiology and Immunology, HB7550, Dartmouth Medical School, Hanover NH 03755, USA.
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Fedoryak OD, Searls Y, Smirnova IV, Burns DM, Stehno-Bittel L. Spontaneous Ca2+ oscillations in subcellular compartments of vascular smooth muscle cells rely on different Ca2+ pools. Cell Res 2005; 14:379-88. [PMID: 15538970 DOI: 10.1038/sj.cr.7290238] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Spontaneous Ca2+ oscillations in vascular smooth muscle cells have been modeled using a single Ca2+ pool. This report describes spontaneous Ca2+ oscillations dependent on two separate Ca2+ sources for the nuclear versus cytoplasmic compartments. Changes in free intracellular Ca2+ were monitored with ratiometric Ca2+- fluorophores using confocal microscopy. On average, spontaneous oscillations developed in 79% of rat aortic smooth muscle cells that were synchronous between the cytoplasm and nucleus. Reduction of extracellular Ca2+ (less than 1 microM)decreased the frequency and amplitude of the cytoplasmic oscillations with 48% of the oscillations asynchronous between the nuclear and cytoplasmic compartments. Similar results were obtained with the Ca2+ channel blockers, nimodipine and diltiazem. Arg-vasopressin (AVP) induced a rapid release of intracellular Ca2+ stores that was greater in the nuclear compartment (4.20 +/- 0.23 ratio units, n = 56) than cytoplasm (2.54 +/- 0.28) in cells that had spontaneously developed prior oscillations. Conversely, cells in the same conditions lacking oscillations had a greater AVP-induced Ca2+ transient in the cytoplasm (4.99 +/- 0.66, n = 17) than in the nucleus (2.67 +/- 0.29). Pre-treatment with Ca2+ channel blockers depressed the AVP responses in both compartments with the cytoplasmic Ca2+ most diminished. Depletion of internal Ca2+ stores prior to AVP exposure blunted the nuclear response, mimicking the response of cells that lacked prior oscillations. Spontaneous oscillating cells had a greater sarcoplasmic reticulum network than cells that did not oscillate. We propose that spontaneous nuclear oscillations rely on perinuclear sarcoplasmic reticulum stores, while the cytoplasmic oscillations rely on Ca2+ influx.
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Affiliation(s)
- Olesya D Fedoryak
- Department of Physical Therapy, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Abstract
Farnesol, a C(15) natural isoprenoid, exerts complex modulating effects on the membrane permeability of human retinal glial (Müller) cells. Several glial cationic currents were examined. At low micromolar concentrations, farnesol reduced the amplitudes of all fast and depolarization-activated membrane currents expressed by Müller cells, that is, currents through 1) transient low-voltage-activated (LVA; IC(50) = 2.2 microM), 2) sustained high-voltage-activated Ca(2+) channels (HVA; IC(50) = 1.2 microM), 3) fast Na(+) channels (IC(50) = 9.0 microM), and 4) transient (A-type) K(+) channels (IC(50) = 4.7 microM). Furthermore, farnesol shifted the activation of LVA and HVA currents to more depolarized potentials by 21.3 +/- 7.4 mV and 8.3 +/- 4.5 mV, respectively. On the other hand, neither inwardly rectifying nor iberiotoxin-sensitive calcium-activated K(+) currents were affected by farnesol. Therefore, farnesol is assumed to be a biologically active substance that regulates ion channel activity in the glial cell membrane. Depressing rapid changes of the membrane potential and supporting a stable hyperpolarized status of the glial cells may enhance the efficiency of crucial glial functions such as extracellular K(+) clearance and neurotransmitter uptake.
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Affiliation(s)
- A Bringmann
- Department of Neurophysiology, Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany.
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Abstract
OBJECTIVES To study calcium metabolism in pre-eclampsia and normotensive gravid women. METHOD Ten milliliters of heparinized blood samples and 24-h urine samples were collected from 50 pre-eclamptic and 50 normotensive primigravidae. Blood samples were studied for calcium uptake, intracellular calcium level and calcium-dependent adenosine triphosphatase activity of red blood cell ghost. Urinary calcium excretion was estimated from the 24-h urine samples. These values were compared in the two groups. RESULTS The mean gestational age at recruitment was similar in both the groups. The mean maternal age was 24.28 +/- 2.41 years in pre-eclamptic and 23.48 +/- 4.16 years in normotensive women. In pre-eclampsia 24-h urinary calcium excretion (71.20 +/- 22.95 mg/day) and calcium-dependent ATPase activity (10.78 +/- 2.40 nmol/Pi/mg protein/min) was significantly lower compared to normotensive primigravidae (calcium excretion = 189.24 +/- 57.06 mg/day; Ca2+-dependent ATPase = 12.64 +/- 2.42 nmolPi/mg /protein per min; P < 0.001). Intracellular calcium levels and calcium uptake at 10 min by red blood cells were significantly higher in pre-eclampsia (P < 0.05). Calcium uptake by red blood cells at 20 and 30 min was similar in both groups. CONCLUSION Pre-eclampsia is associated with increased levels of intracellular calcium, decreased calcium-dependent ATPase activity of erythrocytes and hypocalciuria.
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Affiliation(s)
- J Ray
- Department of Obstetrics and Gynecology, and Experimental Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Luft UC, Bychkov R, Gollasch M, Gross V, Roullet JB, McCarron DA, Ried C, Hofmann F, Yagil Y, Yagil C, Haller H, Luft FC. Farnesol blocks the L-type Ca2+ channel by targeting the alpha 1C subunit. Arterioscler Thromb Vasc Biol 1999; 19:959-66. [PMID: 10195923 DOI: 10.1161/01.atv.19.4.959] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We recently demonstrated that farnesol, a 15-carbon isoprenoid, blocks L-type Ca2+ channels in vascular smooth muscle cells. To elucidate farnesol's mechanism of action, we performed whole-cell and perforated-patch clamp experiments in rat aortic A7r5 cells and in Chinese hamster ovary (CHO) C9 cells expressing smooth muscle Ca2+ channel alpha 1C subunits. Farnesol dose-dependently and voltage-independently inhibited Ba2+ currents in both A7r5 and CHOC9 cells, with similar half-maximal inhibitions at 2.6 and 4.3 micromol/L, [corrected] respectively (P=NS). In both cell lines, current inhibition by farnesol was prominent over the whole voltage range without changes in the current-voltage relationship peaks. Neither intracellular infusion of the stable GDP analogue guanosine-5'-O-(2-thiodiphosphate) (100 micromol/L) [corrected] via the patch pipette nor strong conditioning membrane depolarization prevented the inhibitory effect of farnesol, which indicates G protein-independent inhibition of Ca2+ channels. In an analysis of the steady-state inactivation curve for voltage dependence, farnesol induced a significant, negative shift ( approximately 10 mV) of the potential causing 50% channel inactivation in both cell lines (P<0. 001). In contrast, the steepness factor characterizing the voltage sensitivity of the channels was unaffected. Unlike pharmacological Ca2+ channel blockers, farnesol blocked Ca2+ currents in the resting state: initial block was 63+/-8% in A7r5 cells and 50+/-9% in CHOC9 cells at a holding potential of -80 mV. We then gave 500 mg/kg body weight farnesol by gavage to Sabra hypertensive and normotensive rats and found that farnesol reduced blood pressure significantly in the hypertensive strain for at least 48 hours. We conclude that farnesol may represent an endogenous smooth muscle L-type Ca2+ channel antagonist. Because farnesol is active in cells expressing only the pore-forming alpha1 subunit, the data further suggest that this subunit represents the molecular target for farnesol binding and principal action. Finally, farnesol has a blood pressure-lowering action that may be relevant in vivo.
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Affiliation(s)
- U C Luft
- Franz Volhard Clinic and Max Delbrück Center for Molecular Medicine, Virchow Klinikum-Charité, Humboldt University of Berlin, Berlin, Germany.
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