1
|
López-González I, Sánchez-Cárdenas C, De la Vega-Beltrán JL, Alvarado-Quevedo B, Ocelotl-Oviedo JP, González-Cota AL, Aldana A, Orta G, Darszon A. ATP increases head volume in capacitated human sperm via a purinergic channel. Biochem Biophys Res Commun 2023; 671:318-326. [PMID: 37327703 DOI: 10.1016/j.bbrc.2023.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 06/02/2023] [Indexed: 06/18/2023]
Abstract
Scanning ion-conductance microscopy allowed us to document an external Ca2+ dependent ATP driven volume increase (ATPVI) in capacitated human sperm heads. We examined the involvement of purinergic receptors (PRs) P2X2R and P2X4R in ATPVI using their co-agonists progesterone and Ivermectin (Iver), and Cu2+, which co-activates P2X2Rs and inhibits P2X4Rs. Iver enhanced ATPVI and Cu2+ and 5BDBD inhibited it, indicating P2X4Rs contributed to this response. Moreover, Cu2+ and 5BDBD inhibited the ATP-induced acrosome reaction (AR) which was enhanced by Iver. ATP increased the concentration of intracellular Ca2+ ([Ca2+]i) in >45% of individual sperm, most of which underwent AR monitored using FM4-64. Our findings suggest that human sperm P2X4R activation by ATP increases [Ca2+]i mainly due to Ca2+ influx which leads to a sperm head volume increase, likely involving acrosomal swelling, and resulting in AR.
Collapse
Affiliation(s)
- I López-González
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
| | - C Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - J L De la Vega-Beltrán
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - B Alvarado-Quevedo
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - J P Ocelotl-Oviedo
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - A L González-Cota
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - A Aldana
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - G Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico
| | - A Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210, Mexico.
| |
Collapse
|
2
|
Yang F, Gracia Gervasi M, Orta G, Tourzani DA, De la Vega-Beltrán JL, Ruthel G, Darszon A, Visconti PE, Wang PJ. C2CD6 regulates targeting and organization of the CatSper calcium channel complex in sperm flagella. Development 2022; 149:dev199988. [PMID: 34919125 PMCID: PMC8774747 DOI: 10.1242/dev.199988] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 12/01/2021] [Indexed: 11/20/2022]
Abstract
The CatSper cation channel is essential for sperm capacitation and male fertility. The multi-subunit CatSper complexes form highly organized calcium signaling nanodomains on flagellar membranes. Here, we report identification of an uncharacterized protein, C2CD6, as a subunit of the mouse CatSper complex. C2CD6 contains a calcium-dependent, membrane-targeting C2 domain. C2CD6 associates with the CatSper calcium-selective, core-forming subunits. Deficiency of C2CD6 depletes the CatSper nanodomains from the flagellum and results in male sterility. C2CD6-deficient sperm are defective in hyperactivation and fail to fertilize oocytes both in vitro and in vivo. CatSper currents are present but at a significantly lower level in C2CD6-deficient sperm. Transient treatments with either Ca2+ ionophore, starvation, or a combination of both restore the fertilization capacity of C2CD6-deficient sperm. C2CD6 interacts with EFCAB9, a pH-dependent calcium sensor in the CatSper complex. We postulate that C2CD6 facilitates incorporation of the CatSper complex into the flagellar plasma membrane and may function as a calcium sensor. The identification of C2CD6 may enable the long-sought reconstitution of the CatSper ion channel complex in a heterologous system for male contraceptive development.
Collapse
Affiliation(s)
- Fang Yang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Maria Gracia Gervasi
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, México
| | - Darya A. Tourzani
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Jose Luis De la Vega-Beltrán
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, México
| | - Gordon Ruthel
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, México
| | - Pablo E. Visconti
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - P. Jeremy Wang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| |
Collapse
|
3
|
Loyo-Celis V, Orta G, Beltrán C, Darszon A. CatSper channels in sea urchin sperm. Cell Calcium 2021; 99:102466. [PMID: 34509139 DOI: 10.1016/j.ceca.2021.102466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/13/2021] [Accepted: 08/26/2021] [Indexed: 11/16/2022]
Abstract
Sea urchin sperm swimming is regulated by speract, a decapeptide released from egg jelly that induces chemotaxis and triggers membrane potential (Em) changes, intracellular increases in cyclic nucleotides (cGMP, cAMP), pH (pHi) and calcium concentration ([Ca2+]i). The identity of the ionic transporters associated with the [Ca2+]i changes required for chemotaxis is not fully known. CatSper, a sperm exclusive Ca2+ channel has been detected by proteomic analysis and immunofluorescence in sea urchin sperm and there is evidence for its involvement in chemotaxis. This work presents an electrophysiological characterization of a CatSper channel in sea urchin sperm. By swelling sperm suspending them in 10-fold diluted artificial sea water (ASW) we achieve on-cell patch-clamp recordings that document a mildly voltage and pHi dependent Na+ permeable channel (in absence of divalent ions in the pipette), sensitive to speract, and blocked by Mibefradil (Mibe), NNC55-0396 (NNC) and RU1968 (RU) resembling CatSper. We also recorded a voltage dependent Cl- channel inhibited by Niflumic Acid and the TMEM16A blocker.
Collapse
Affiliation(s)
- Verónica Loyo-Celis
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Carmen Beltrán
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
| |
Collapse
|
4
|
Luque GM, Xu X, Romarowski A, Gervasi MG, Orta G, De la Vega-Beltrán JL, Stival C, Gilio N, Dalotto-Moreno T, Krapf D, Visconti PE, Krapf D, Darszon A, Buffone MG. Cdc42 localized in the CatSper signaling complex regulates cAMP-dependent pathways in mouse sperm. FASEB J 2021; 35:e21723. [PMID: 34224609 DOI: 10.1096/fj.202002773rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/19/2021] [Accepted: 05/24/2021] [Indexed: 11/11/2022]
Abstract
Sperm acquire the ability to fertilize in a process called capacitation and undergo hyperactivation, a change in the motility pattern, which depends on Ca2+ transport by CatSper channels. CatSper is essential for fertilization and it is subjected to a complex regulation that is not fully understood. Here, we report that similar to CatSper, Cdc42 distribution in the principal piece is confined to four linear domains and this localization is disrupted in CatSper1-null sperm. Cdc42 inhibition impaired CatSper activity and other Ca2+ -dependent downstream events resulting in a severe compromise of the sperm fertilizing potential. We also demonstrate that Cdc42 is essential for CatSper function by modulating cAMP production by soluble adenylate cyclase (sAC), providing a new regulatory mechanism for the stimulation of CatSper by the cAMP-dependent pathway. These results reveal a broad mechanistic insight into the regulation of Ca2+ in mammalian sperm, a matter of critical importance in male infertility as well as in contraception.
Collapse
Affiliation(s)
- Guillermina M Luque
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Xinran Xu
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, USA
| | - Ana Romarowski
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Department of Veterinary and Animal Science, University of Massachusetts, Amherst, MA, USA
| | - María G Gervasi
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, MA, USA
| | - Gerardo Orta
- Instituto de Biotecnología, UNAM, Cuernavaca, México
| | | | - Cintia Stival
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Rosario, Santa Fe, Argentina
| | - Nicolás Gilio
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Tomás Dalotto-Moreno
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Dario Krapf
- Instituto de Biología Molecular y Celular de Rosario (CONICET-UNR), Rosario, Santa Fe, Argentina
| | - Pablo E Visconti
- Department of Veterinary and Animal Science, University of Massachusetts, Amherst, MA, USA
| | - Diego Krapf
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, CO, USA
| | | | - Mariano G Buffone
- Instituto de Biología y Medicina Experimental (IBYME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| |
Collapse
|
5
|
Sánchez-Cárdenas C, Romarowski A, Orta G, De la Vega-Beltrán JL, Martín-Hidalgo D, Hernández-Cruz A, Visconti PE, Darszon A. Starvation induces an increase in intracellular calcium and potentiates the progesterone-induced mouse sperm acrosome reaction. FASEB J 2021; 35:e21528. [PMID: 33742713 DOI: 10.1096/fj.202100122r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/26/2022]
Abstract
We have recently reported two different methodologies that improve sperm functionality. The first method involved transient exposure to the Ca2+ ionophore A23187 , and the second required sperm incubation in the absence of energy nutrients (starvation). Both methods were associated with an initial loss of motility followed by a rescue step involving ionophore removal or addition of energy metabolites, respectively. In this work, we show that starvation is accompanied by an increase in intracellular Ca2+ ([Ca2+ ]i ). Additionally, the starved cells acquire a significantly enhanced capacity to undergo a progesterone-induced acrosome reaction. Electrophysiological measurements show that CatSper channel remains active in starvation conditions. However, the increase in [Ca2+ ]i was also observed in sperm from CatSper null mice. Upon starvation, addition of energy nutrients reversed the effects on [Ca2+ ]i and decreased the effect of progesterone on the acrosome reaction to control levels. These data indicate that both methods have common molecular features.
Collapse
Affiliation(s)
- Claudia Sánchez-Cárdenas
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM, Cuernavaca, México
| | - Ana Romarowski
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM, Cuernavaca, México
| | - José Luis De la Vega-Beltrán
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM, Cuernavaca, México
| | - David Martín-Hidalgo
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA.,Research Group of Intracellular Signalling and Technology of Reproduction (Research Institute INBIO G+C), University of Extremadura, Cáceres, Spain
| | - Arturo Hernández-Cruz
- Departamento de Neurociencia Cognitiva and Laboratorio Nacional de Canalopatías, Instituto de Fisiología Celular, UNAM, Ciudad Universitaria, México, México
| | - Pablo E Visconti
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM, Cuernavaca, México
| |
Collapse
|
6
|
Zhao R, Dai H, Arias RJ, De Blas GA, Orta G, Pavarotti MA, Shen R, Perozo E, Mayorga LS, Darszon A, Goldstein SAN. Direct activation of the proton channel by albumin leads to human sperm capacitation and sustained release of inflammatory mediators by neutrophils. Nat Commun 2021; 12:3855. [PMID: 34158477 PMCID: PMC8219737 DOI: 10.1038/s41467-021-24145-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 06/02/2021] [Indexed: 02/05/2023] Open
Abstract
Human voltage-gated proton channels (hHv1) extrude protons from cells to compensate for charge and osmotic imbalances due metabolism, normalizing intracellular pH and regulating protein function. Human albumin (Alb), present at various levels throughout the body, regulates oncotic pressure and transports ligands. Here, we report Alb is required to activate hHv1 in sperm and neutrophils. Dose-response studies reveal the concentration of Alb in semen is too low to activate hHv1 in sperm whereas the higher level in uterine fluid yields proton efflux, allowing capacitation, the acrosomal reaction, and oocyte fertilization. Likewise, Alb activation of hHv1 in neutrophils is required to sustain production and release of reactive oxygen species during the immune respiratory burst. One Alb binds to both voltage sensor domains (VSDs) in hHv1, enhancing open probability and increasing proton current. A computational model of the Alb-hHv1 complex, validated by experiments, identifies two sites in Alb domain II that interact with the VSDs, suggesting an electrostatic gating modification mechanism favoring the active "up" sensor conformation. This report shows how sperm are triggered to fertilize, resolving how hHv1 opens at negative membrane potentials in sperm, and describes a role for Alb in physiology that will operate in the many tissues expressing hHv1.
Collapse
Affiliation(s)
- Ruiming Zhao
- Departments of Pediatrics and Physiology & Biophysics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, CA, USA
| | - Hui Dai
- Departments of Pediatrics and Physiology & Biophysics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, CA, USA
| | - Rodolfo J Arias
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Gerardo A De Blas
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
- Laboratorio de Telediagnóstico e Investigación Traslacional (LaTIT). Área de Farmacología. Departamento de Patología, School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Martín A Pavarotti
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Rong Shen
- Department of Biochemistry and Molecular Biology, Gordon Center for Integrative Science, University of Chicago, Chicago, IL, USA
| | - Eduardo Perozo
- Department of Biochemistry and Molecular Biology, Gordon Center for Integrative Science, University of Chicago, Chicago, IL, USA
| | - Luis S Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Steve A N Goldstein
- Departments of Pediatrics and Physiology & Biophysics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, CA, USA.
| |
Collapse
|
7
|
Abstract
The mitochondrial BKCa channel (mitoBKCa) is a splice variant of plasma membrane BKCa (Maxi-K, BKCa, Slo1, KCa1.1). While a high-resolution structure of mitoBKCa is not available yet, functional and structural studies of the plasma membrane BKCa have provided important clues on the gating of the channel by voltage and Ca2+, as well as the interaction with auxiliary subunits. To date, we know that the control of expression of mitoBKCa, targeting and voltage-sensitivity strongly depends on its association with its regulatory β1-subunit, which overall participate in the control of mitochondrial Ca2+-overload in cardiac myocytes. Moreover, novel regulatory mechanisms of mitoBKCa such as β-subunits and amyloid-β have recently been proposed. However, major basic questions including how the regulatory BKCa-β1-subunit reaches mitochondria and the mechanism through which amyloid-β impairs mitoBKCa channel function remain to be addressed.
Collapse
Affiliation(s)
- Ana L González-Cota
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM. Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Carmen Santana-Calvo
- Instituto Gulbenkian de Ciência. Rua da Quinta Grande 6, Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universida de Nova de Lisboa. Av. da República, Oeiras, Portugal
| | - Rocío Servín-Vences
- Department of Neuroscience, The Scripps Research Institute. 10550 North Torrey Pines Road, La Jolla, CA, USA
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM. Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Enrique Balderas
- Nora Eccles Harrison Cardiovascular Research & Training Institute, University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
8
|
Loyo Celis V, Orta G, Beltran C, Darszon A. Electrophysiological Characterization of CatSper Channel in Sea Urchin Sperm. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
9
|
Orta G, de la Vega-Beltran JL, Martín-Hidalgo D, Santi CM, Visconti PE, Darszon A. CatSper channels are regulated by protein kinase A. J Biol Chem 2018; 293:16830-16841. [PMID: 30213858 DOI: 10.1074/jbc.ra117.001566] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 09/05/2018] [Indexed: 11/06/2022] Open
Abstract
Mammalian sperm must undergo capacitation as a preparation for entering into hyperactivated motility, undergoing the acrosome reaction, and acquiring fertilizing ability. One of the initial capacitation events occurs when sperm encounter an elevated HCO3 - concentration. This anion activates the atypical adenylyl cyclase Adcy10, increases intracellular cAMP, and stimulates protein kinase A (PKA). Moreover, an increase in intracellular Ca2+ concentration ([Ca2+] i ) is essential for sperm capacitation. Although a cross-talk between cAMP-dependent pathways and Ca2+ clearly plays an essential role in sperm capacitation, the connection between these signaling events is incompletely understood. Here, using three different approaches, we found that CatSper, the main sperm Ca2+ channel characterized to date, is up-regulated by a cAMP-dependent activation of PKA in mouse sperm. First, HCO3 - and the PKA-activating permeable compound 8-Br-cAMP induced an increase in [Ca2+] i , which was blocked by the PKA peptide inhibitor PKI, and H89, another PKA inhibitor, also abrogated the 8-Br-cAMP response. Second, HCO3 - increased the membrane depolarization induced upon divalent cation removal by promoting influx of monovalent cations through CatSper channels, which was inhibited by PKI, H89, and the CatSper blocker HC-056456. Third, electrophysiological patch clamp, whole-cell recordings revealed that CatSper activity is up-regulated by HCO3 - and by direct cAMP injection through the patch-clamp pipette. The activation by HCO3 - and cAMP was also blocked by PKI, H89, Rp-cAMPS, and HC-056456, and electrophysiological recordings in sperm from CatSper-KO mice confirmed CatSper's role in these activation modes. Our results strongly suggest that PKA-dependent phosphorylation regulates [Ca2+] i homeostasis by activating CatSper channel complexes.
Collapse
Affiliation(s)
- Gerardo Orta
- From the Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | - José Luis de la Vega-Beltran
- From the Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | - David Martín-Hidalgo
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts 01003, and
| | - Celia M Santi
- Department of Obstetrics and Gynecology and.,Department of Neurosciences, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Pablo E Visconti
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts 01003, and
| | - Alberto Darszon
- From the Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México,
| |
Collapse
|
10
|
Ernesto JI, Weigel Muñoz M, Battistone MA, Vasen G, Martínez-López P, Orta G, Figueiras-Fierro D, De la Vega-Beltran JL, Moreno IA, Guidobaldi HA, Giojalas L, Darszon A, Cohen DJ, Cuasnicú PS. CRISP1 as a novel CatSper regulator that modulates sperm motility and orientation during fertilization. J Cell Biol 2015; 210:1213-24. [PMID: 26416967 PMCID: PMC4586743 DOI: 10.1083/jcb.201412041] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ca(2+)-dependent mechanisms are critical for successful completion of fertilization. Here, we demonstrate that CRISP1, a sperm protein involved in mammalian fertilization, is also present in the female gamete and capable of modulating key sperm Ca(2+) channels. Specifically, we show that CRISP1 is expressed by the cumulus cells that surround the egg and that fertilization of cumulus-oocyte complexes from CRISP1 knockout females is impaired because of a failure of sperm to penetrate the cumulus. We provide evidence that CRISP1 stimulates sperm orientation by modulating sperm hyperactivation, a vigorous motility required for penetration of the egg vestments. Moreover, patch clamping of sperm revealed that CRISP1 has the ability to regulate CatSper, the principal sperm Ca(2+) channel involved in hyperactivation and essential for fertility. Given the critical role of Ca(2+) for sperm motility, we propose a novel CRISP1-mediated fine-tuning mechanism to regulate sperm hyperactivation and orientation for successful penetration of the cumulus during fertilization.
Collapse
Affiliation(s)
- Juan I Ernesto
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428ADN Buenos Aires, Argentina
| | - Mariana Weigel Muñoz
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428ADN Buenos Aires, Argentina
| | - María A Battistone
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428ADN Buenos Aires, Argentina
| | - Gustavo Vasen
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428ADN Buenos Aires, Argentina
| | - Pablo Martínez-López
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | - Dulce Figueiras-Fierro
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | - José L De la Vega-Beltran
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | | | - Héctor A Guidobaldi
- Centro de Biología Celular y Molecular, Instituto de Investigaciones Biológicas y Tecnológicas, Universidad Nacional de Córdoba, X5016GCA Córdoba, Argentina
| | - Laura Giojalas
- Centro de Biología Celular y Molecular, Instituto de Investigaciones Biológicas y Tecnológicas, Universidad Nacional de Córdoba, X5016GCA Córdoba, Argentina
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos 62250, México
| | - Débora J Cohen
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428ADN Buenos Aires, Argentina
| | - Patricia S Cuasnicú
- Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas, C1428ADN Buenos Aires, Argentina
| |
Collapse
|
11
|
Figueiras-Fierro D, Acevedo JJ, Martínez-López P, Escoffier J, Sepúlveda FV, Balderas E, Orta G, Visconti PE, Darszon A. Electrophysiological evidence for the presence of cystic fibrosis transmembrane conductance regulator (CFTR) in mouse sperm. J Cell Physiol 2013; 228:590-601. [PMID: 22833409 DOI: 10.1002/jcp.24166] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 07/17/2012] [Indexed: 01/25/2023]
Abstract
Mammalian sperm must undergo a maturational process, named capacitation, in the female reproductive tract to fertilize the egg. Sperm capacitation is regulated by a cAMP/protein kinase A (PKA) pathway and involves increases in intracellular Ca(2+), pH, Cl(-), protein tyrosine phosphorylation, and in mouse and some other mammals a membrane potential hyperpolarization. The cystic fibrosis transmembrane conductance regulator (CFTR), a Cl(-) channel modulated by cAMP/PKA and ATP, was detected in mammalian sperm and proposed to modulate capacitation. Our whole-cell patch-clamp recordings from testicular mouse sperm now reveal a Cl(-) selective component to membrane current that is ATP-dependent, stimulated by cAMP, cGMP, and genistein (a CFTR agonist, at low concentrations), and inhibited by DPC and CFTR(inh) -172, two well-known CFTR antagonists. Furthermore, the Cl(-) current component activated by cAMP and inhibited by CFTR(inh) -172 is absent in recordings on testicular sperm from mice possessing the CFTR ΔF508 loss-of-function mutation, indicating that CFTR is responsible for this component. A Cl(-) selective like current component displaying CFTR characteristics was also found in wild type epididymal sperm bearing the cytoplasmatic droplet. Capacitated sperm treated with CFTR(inh) -172 undergo a shape change, suggesting that CFTR is involved in cell volume regulation. These findings indicate that functional CFTR channels are present in mouse sperm and their biophysical properties are consistent with their proposed participation in capacitation.
Collapse
Affiliation(s)
- Dulce Figueiras-Fierro
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos, Mexico
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Orta G, Ferreira G, José O, Treviño CL, Beltrán C, Darszon A. Human spermatozoa possess a calcium-dependent chloride channel that may participate in the acrosomal reaction. J Physiol 2012; 590:2659-75. [PMID: 22473777 DOI: 10.1113/jphysiol.2011.224485] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Motility, maturation and the acrosome reaction (AR) are fundamental functions of mammalian spermatozoa. While travelling through the female reproductive tract, spermatozoa must mature through a process named capacitation, so that they can reach the egg and undergo the AR, an exocytotic event necessary to fertilize the egg. Though Cl⁻ is important for sperm capacitation and for the AR, not much is known about the molecular identity of the Cl⁻ transporters involved in these processes.We implemented a modified perforated patch-clamp strategy to obtain whole cell recordings sealing on the head of mature human spermatozoa.Our whole cell recordings revealed the presence of a Ca²⁺-dependent Cl⁻ current. The biophysical characteristics of this current and its sensitivity to niflumic acid (NFA) and 4,4-diisothiocyano-2,2-stilbene disulphonic acid (DIDIS) are consistent with those displayed by the Ca²⁺-dependent Cl⁻ channel from the anoctamin family (TMEM16). Whole cell patch clamp recordings in the cytoplasmic droplet of human spermatozoa corroborated the presence of these currents, which were sensitive to NFA and to a small molecule TMEM16A inhibitor (TMEM16Ainh, an aminophenylthiazole). Importantly, the human sperm AR induced by a recombinant human glycoprotein from the zona pellucida, rhZP3, displayed a similar sensitivity to NFA, DIDS and TMEM16Ainh as the sperm Ca²⁺-dependent Cl⁻ currents. Our findings indicate the presence of Ca²⁺-dependent Cl⁻ currents in human spermatozoa, that TMEM16A may contribute to these currents and also that sperm Ca²⁺-dependent Cl⁻ currents may participate in the rhZP3-induced AR.
Collapse
Affiliation(s)
- Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP 62210, México
| | | | | | | | | | | |
Collapse
|
13
|
Martínez-López P, Treviño CL, de la Vega-Beltrán JL, De Blas G, Monroy E, Beltrán C, Orta G, Gibbs GM, O'Bryan MK, Darszon A. TRPM8 in mouse sperm detects temperature changes and may influence the acrosome reaction. J Cell Physiol 2011; 226:1620-31. [DOI: 10.1002/jcp.22493] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
14
|
Brauchi S, Orta G, Mascayano C, Salazar M, Raddatz N, Urbina H, Rosenmann E, Gonzalez-Nilo F, Latorre R. Dissection of the components for PIP2 activation and thermosensation in TRP channels. Proc Natl Acad Sci U S A 2007; 104:10246-51. [PMID: 17548815 PMCID: PMC1891241 DOI: 10.1073/pnas.0703420104] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Indexed: 01/01/2023] Open
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP2) plays a central role in the activation of several transient receptor potential (TRP) channels. The role of PIP2 on temperature gating of thermoTRP channels has not been explored in detail, and the process of temperature activation is largely unexplained. In this work, we have exchanged different segments of the C-terminal region between cold-sensitive (TRPM8) and heat-sensitive (TRPV1) channels, trying to understand the role of the segment in PIP2 and temperature activation. A chimera in which the proximal part of the C-terminal of TRPV1 replaces an equivalent section of TRPM8 C-terminal is activated by PIP2 and confers the phenotype of heat activation. PIP2, but not temperature sensitivity, disappears when positively charged residues contained in the exchanged region are neutralized. Shortening the exchanged segment to a length of 11 aa produces voltage-dependent and temperature-insensitive channels. Our findings suggest the existence of different activation domains for temperature, PIP2, and voltage. We provide an interpretation for channel-PIP2 interaction using a full-atom molecular model of TRPV1 and PIP2 docking analysis.
Collapse
Affiliation(s)
- Sebastian Brauchi
- *Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Cientificos, Valdivia 509-9100, Chile
| | - Gerardo Orta
- *Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Cientificos, Valdivia 509-9100, Chile
| | - Carolina Mascayano
- Centro de Bioinformatica y Simulacion Molecular Simulation Center, Universidad de Talca, Talca 346-0000, Chile
| | - Marcelo Salazar
- *Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Cientificos, Valdivia 509-9100, Chile
| | - Natalia Raddatz
- *Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Cientificos, Valdivia 509-9100, Chile
| | - Hector Urbina
- Centro de Bioinformatica y Simulacion Molecular Simulation Center, Universidad de Talca, Talca 346-0000, Chile
| | - Eduardo Rosenmann
- *Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Cientificos, Valdivia 509-9100, Chile
| | - Fernando Gonzalez-Nilo
- Centro de Bioinformatica y Simulacion Molecular Simulation Center, Universidad de Talca, Talca 346-0000, Chile
| | - Ramon Latorre
- *Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Cientificos, Valdivia 509-9100, Chile
| |
Collapse
|
15
|
Latorre R, Brauchi S, Orta G, Zaelzer C, Vargas G. ThermoTRP channels as modular proteins with allosteric gating. Cell Calcium 2007; 42:427-38. [PMID: 17499848 DOI: 10.1016/j.ceca.2007.04.004] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 03/21/2007] [Indexed: 10/23/2022]
Abstract
Ion channels activate by sensing stimuli such as membrane voltage, ligand binding or temperature and transduce this information into conformational changes that open the channel pore. Thus, a key question in understanding ion channel function is how do the protein domains involved in sensing stimuli (sensors) and opening the pore (gates) communicate. In this regard, transient receptor potential (TRP) channels that confer thermosensation [A. Dhaka, V. Viswanath, A. Patapoutian, TRP ion channels and temperature sensation, Annu. Rev. Neurosci. 29 (2006) 135-161; I.S. Ramsey, M. Delling, D.E. Clapham, An introduction to TRP channels, Annu. Rev. Physiol. 68 (2006) 619-647] (thermoTRP; Q(10)>10) are unique to the extent that they integrate a variety of physical and chemical stimuli. In some cases such as, for example, the vanilloid receptor TRPV1 [M.J. Caterina, M.A. Schumacher, M. Tominaga, T.A. Rosen, J.D. Levine, D. Julius, The capsaicin receptor: a heat-activated ion channel in the pain pathway, Nature 389 (1997) 816-824] and TRPA1 [G.M. Story, A.M. Peier, A.J. Reeve, S.R. Eid, J. Mosbacher, T.R. Hricik, T.J. Earley, A.C. Hergarden, D.A. Andersson, S.W. Hwang, P. McIntyre, T. Jegla, S. Bevan, A. Patapoutian, ANKTM1, a TRP-like channel expressed in nociceptive neurons, is activated by cold temperatures, Cell 112 (2003) 819-829; S. Jordt, D. Julius, Molecular basis for species-specific sensitivity to "hot" chilli peppers, Cell 108 (2002) 421-430] the integration of these stimuli elicit pain [M. Tominaga, M.J. Caterina, A.B. Malmberg, T.A. Rosen, H. Gilbert, K. Skinner, B.E. Raumann, A.I. Basbaum, D. Julius, The cloned capsaicin receptor integrates multiple pain-producing stimuli, Neuron 21 (1998) 531-543; M. Bandell, A. Dubin, M. Petrus, A. Orth, J. Mathur, S. Hwang, A. Patapoutian, High-throughput random mutagenesis screen reveals TRPM8 residues specifically required for activation by menthol, Nat. Neurosci. 9 (2006) 466-468; S. Zurborg, B. Yurgionas, JA. Jira, O. Caspani, P.A. Heppenstall, Direct activation of the ion channel TRPA1 by Ca(2+), Nat. Neurosci. 10 (2007) 277-279]. These stimuli include voltage, pH, agonist binding, and temperature. Understanding how each of these distinct physiological signals regulate channel opening will be informative about the mechanical linkages that can act either independently or in concert to influence channel activation. In this paper we show that thermoTRP channel-forming proteins are modular in the sense that certain structure or structures (modules) confer temperature-dependent regulation, whereas others confer voltage-dependent regulation. We also discuss the thermodynamic basis of heat and cold activation in an effort to elucidate what confer to these channels the capability to be gated by temperature directly.
Collapse
Affiliation(s)
- Ramon Latorre
- Laboratory of Biophysics and Molecular Physiology, Centro de Estudios Científicos, Valdivia 5110246, Chile.
| | | | | | | | | |
Collapse
|
16
|
Brauchi S, Vargas G, Latorre R, Orta G. Voltage and Temperature Gating of ThermoTRP Channels. TRP Ion Channel Function in Sensory Transduction and Cellular Signaling Cascades 2006. [DOI: 10.1201/9781420005844.ch21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
17
|
Brauchi S, Orta G, Salazar M, Rosenmann E, Latorre R. A hot-sensing cold receptor: C-terminal domain determines thermosensation in transient receptor potential channels. J Neurosci 2006; 26:4835-40. [PMID: 16672657 PMCID: PMC6674176 DOI: 10.1523/jneurosci.5080-05.2006] [Citation(s) in RCA: 221] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Temperature transduction in mammals is possible because of the presence of a set of temperature-dependent transient receptor potential (TRP) channels in dorsal root ganglia neurons and skin cells. Six thermo-TRP channels, all characterized by their unusually high temperature sensitivity (Q10 > 10), have been cloned: TRPV1-4 are heat activated, whereas TRPM8 and TRPA1 are activated by cold. Because of the lack of structural information, the molecular basis for regulation by temperature remains unknown. In this study, we assessed the role of the C-terminal domain of thermo-TRPs and its involvement in thermal activation by using chimeras between the heat receptor TRPV1 and the cold receptor TRPM8, in which the entire C-terminal domain was switched. Here, we demonstrate that the C-terminal domain is modular and confers the channel phenotype regarding temperature sensitivity, channel gating kinetics, and PIP2 (phosphatidylinositol-4,5-bisphophate) modulation. Thus, thermo-TRP channels contain an interchangeable specific region, different from the voltage sensor, which allows them to sense temperature stimuli.
Collapse
|
18
|
Alvarez JL, Salinas-Stefanon E, Orta G, Ferrer T, Talavera K, Galán L, Vassort G. Occurrence of a tetrodotoxin-sensitive calcium current in rat ventricular myocytes after long-term myocardial infarction. Cardiovasc Res 2004; 63:653-61. [PMID: 15306221 DOI: 10.1016/j.cardiores.2004.05.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2003] [Revised: 05/13/2004] [Accepted: 05/18/2004] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To determine the characteristics of a TTX-sensitive Ca(2+) current that occurred only following remodelling after myocardial infarction in Wistar rat. METHODS Using the whole-cell patch-clamp technique, we studied ionic inward current in myocytes isolated from four different ventricular regions of control Wistar rat hearts, or from hearts 4 to 6 months after ligation of the left coronary artery. Inward current characteristics were also analysed in Xenopus laevis oocytes that heterologously expressed the human sodium channel alpha-subunit Nav1.5. The effects of oxidative stress by hydrogen peroxide or tert-butyl-hydroxyperoxide as well as those of PKA-dependent phosphorylation, which partly mimic the pathological conditions, were investigated on control cardiomyocytes and Nav1.5-expressing oocytes. RESULTS In Na-free solution, a low-threshold, tetrodotoxin-sensitive inward current was found in 20 out of 78 cells isolated from 16 post-myocardial infarcted (PMI) cardiomyocytes but not in cardiomyocytes from young and sham rat hearts. This current exhibited kinetics and pharmacological properties similar to the I(Ca(TTX)) current previously reported. I(Ca(TTX))-like current was critically dependent on extracellular Na(+) and was reduced by micromolar Na(+) concentrations. Neither in normal rat cardiomyocytes nor in Nav1.5-expressing oocytes could a I(Ca(TTX))-like current be elicited in Na(+)-free extracellular solution, even after oxidative stress or PKA-dependent phosphorylation. CONCLUSIONS Our data suggest that I(Ca(TTX))-like current in PMI myocytes does not arise from classical Na(+) channels modified by oxidative stress or PKA phosphorylation and most probably represents a different Na(+) channel type re-expressed in some cells after remodelling.
Collapse
Affiliation(s)
- Julio L Alvarez
- INSERM U-390, Physiopathologie Cardiovasculaire, CHU Arnaud de Villeneuve, 371 Avenue du Doyen Gaston Giraud, F-34295 Montpellier Cedex 5, France
| | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
In long term treatment, thiazide diuretics such as hydrochlorothiazide (HCTZ) lower blood pressure by decreasing peripheral resistance rather than by their diuretic effect. This action has been attributed to the opening of Ca2+-activated K+ channels in vascular smooth muscle cells. However, little is known about their cardiac cellular actions. Here we investigated the possible actions of HCTZ on action potential and contraction of rat ventricular muscle strips and on the ionic currents of isolated rat ventricular cardiomyocytes. HCTZ depressed ventricular contraction with an IC30 of 1.85 microM (60% decrease at 100 microM). Action potential duration at -60 mV and maximal rate of depolarization were, however, only slightly decreased by 12% and 22%, respectively, at 100 microM. At the single cell level, HCTZ (100 microM) depressed the fast Na+ current (INa) and the L-type Ca2+ current (ICaL) by 30% and 20%, respectively. The effects on ICaL were not voltage-or frequency-dependent. In cells intracellularly perfused with 50 microM cyclic adenosine, monophosphate HCTZ reduced ICaL by 33%. The transient (Ito), the delayed rectifier and the inward rectifier potassium currents were decreased by 20% at 100 microM HCTZ. The effects on Ito were voltage-dependent. In conclusion, HCTZ at high concentrations possesses a negative inotropic action that could be in part due to its blocking action on INa and ICaL. The actions of HCTZ on multiple cardiac ionic currents could explain its weak effect on action potential duration.
Collapse
Affiliation(s)
- L Galán
- Laboratorio de Electrofisiología, Instituto de Cardiología y Cirugía Cardiovascular, La Habana, Cuba Laboratorio de Fisiología Cardiovascular, Instituto de Fisiología, Universidad Autónoma de Puebla, Puebla, Mexico
| | | | | | | | | | | | | | | |
Collapse
|