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Ramírez-Hernández D, López-Sánchez P, Lezama-Martínez D, Kuyoc-Arroyo NM, Rodríguez-Rodríguez JE, Fonseca-Coronado S, Valencia-Hernández I, Flores-Monroy J. Timing Matters: Effects of Early and Late Estrogen Replacement Therapy on Glucose Metabolism and Vascular Reactivity in Ovariectomized Aged Wistar Rats. J Renin Angiotensin Aldosterone Syst 2023; 2023:6683989. [PMID: 38025203 PMCID: PMC10665112 DOI: 10.1155/2023/6683989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 10/16/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023] Open
Abstract
Cardiovascular disease incidence increases after menopause due to the loss of estrogen cardioprotective effects. However, there are conflicting data regarding the timing of estrogen therapy (ERT) and its effect on vascular dysfunction associated with impaired glucose metabolism. The aim of this work was to evaluate the effect of early and late ERT on blood glucose/insulin balance and vascular reactivity in aged ovariectomized Wistar rats. Eighteen-month-old female Wistar rats were randomized as follows: (1) sham, (2) 10-week postovariectomy (10 w), (3) 10 w postovariectomy+early estradiol therapy (10 w-early E2), (4) 20-week postovariectomy (20 w), and (5) 20-week postovariectomy+late estradiol therapy (20 w-late E2). Early E2 was administered 3 days after ovariectomy and late therapy after 10 weeks, in both groups. 17β-Estradiol (E2) was administered daily for 10 weeks (5 μg/kg/day). Concentration-response curves to angiotensin II, KCl, and acetylcholine (ACh) were performed. Heart rate (HR), diastolic and systolic blood pressure (DBP and SBP), glucose, insulin, HOMA-IR, and nitric oxide (NO) levels were determined. Higher glucose levels were found in all groups compared to the sham group, except the 20 w-late E2 group. Insulin was increased in all ovariectomized groups compared to sham. The HOMA-IR index showed insulin resistance in all ovariectomized groups, except for the 10 w-early E2 group. The 10 w-early E2 group increased NO levels vs. the 10 w group. After 10 w postovariectomy, the vascular response to KCl and Ach increases, despite early E2 administration. Early and late E2 treatment decreased vascular reactivity to Ang II. At 20-week postovariectomy, DBP increased, even with E2 administration, while SBP and HR remained unchanged. The effects of E2 therapy on blood glucose/insulin balance and vascular reactivity depend on the timing of therapy. Early ERT may provide some protective effects on insulin resistance and vascular function, whereas late ERT may not have the same benefits.
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Affiliation(s)
- Diana Ramírez-Hernández
- Myocardial Pharmacology Laboratory, Faculty of Higher Studies Cuautitlan, National Autonomous University of Mexico, 54740 State of Mexico, Mexico
| | - Pedro López-Sánchez
- Laboratorio de Farmacología Molecular, Escuela Superior de Medicina, Instituto Politécnico Nacional, 11340 Ciudad de México, Mexico
| | - Diego Lezama-Martínez
- Myocardial Pharmacology Laboratory, Faculty of Higher Studies Cuautitlan, National Autonomous University of Mexico, 54740 State of Mexico, Mexico
| | - Neidy M. Kuyoc-Arroyo
- Myocardial Pharmacology Laboratory, Faculty of Higher Studies Cuautitlan, National Autonomous University of Mexico, 54740 State of Mexico, Mexico
| | - Jessica E. Rodríguez-Rodríguez
- Biological Pharmaceutical Chemist Career, Faculty of Higher Education Zaragoza, National Autonomous University of Mexico, Batalla 5 de Mayo S/N, Ejército de Oriente, Iztapalapa, 09230 Mexico City, Mexico
- Laboratory 7, Biomedicine Unit, Faculty of Higher Education Iztacala, National Autonomous University of Mexico, Avenida de los Barrios 1, Los Reyes Ixtacala, 54090 Tlalnepantla de Baz, Mexico
| | - Salvador Fonseca-Coronado
- Immunology Laboratory, Faculty of Higher Studies Cuautitlan, National Autonomous University of Mexico, 54740 State of Mexico, Mexico
| | - Ignacio Valencia-Hernández
- Laboratorio de Farmacología Cardiovascular, Escuela Superior de Medicina, Instituto Politécnico Nacional, 11340 Ciudad de México, Mexico
| | - Jazmin Flores-Monroy
- Myocardial Pharmacology Laboratory, Faculty of Higher Studies Cuautitlan, National Autonomous University of Mexico, 54740 State of Mexico, Mexico
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Duncan PJ, Romanò N, Nair SV, Murray JF, Le Tissier P, Shipston MJ. Sex differences in pituitary corticotroph excitability. Front Physiol 2023; 14:1205162. [PMID: 37534368 PMCID: PMC10391550 DOI: 10.3389/fphys.2023.1205162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/05/2023] [Indexed: 08/04/2023] Open
Abstract
Stress-related illness represents a major burden on health and society. Sex differences in stress-related disorders are well documented, with women having twice the lifetime rate of depression compared to men and most anxiety disorders. Anterior pituitary corticotrophs are central components of the hypothalamic-pituitary-adrenal (HPA) axis, receiving input from hypothalamic neuropeptides corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP), while regulating glucocorticoid output from the adrenal cortex. The dynamic control of electrical excitability by CRH/AVP and glucocorticoids is critical for corticotroph function; however, whether corticotrophs contribute to sexually differential responses of the HPA axis, which might underlie differences in stress-related disorders, is very poorly understood. Using perforated patch clamp electrophysiology in corticotrophs from mice expressing green fluorescent protein under the control of the Pomc promoter, we characterized basal and secretagogue-evoked excitability. Both male and female corticotrophs show predominantly single-spike action potentials under basal conditions; however, males predominantly display spikes with small-amplitude (<20 mV) afterhyperpolarizations (B-type), whereas females displayed a mixture of B-type spikes and spikes with a large-amplitude (>25 mV) afterhyperpolarization (A-type). In response to CRH, or CRH/AVP, male cells almost exclusively transition to a predominantly pseudo-plateau bursting, whereas only female B-type cells display bursting in response to CRH±AVP. Treatment of male or female corticotrophs with 1 nM estradiol (E2) for 24-72 h has no effect on the proportion of cells with A- or B-type spikes in either sex. However, E2 results in the cessation of CRH-induced bursting in both male and female corticotrophs, which can be partially reversed by adding a BK current using a dynamic clamp. RNA-seq analysis of purified corticotrophs reveals extensive differential gene expression at the transcriptional level, including more than 71 mRNAs encoding ion channel subunits. Interestingly, there is a two-fold lower level (p < 0.01) of BK channel pore-forming subunit (Kcnma1) expression in females compared to males, which may partially explain the decrease in CRH-induced bursting. This study identified sex differences at the level of the anterior pituitary corticotroph ion channel landscape and control of both spontaneous and CRH-evoked excitability. Determining the mechanisms of sex differences of corticotroph and HPA activity at the cellular level could be an important step for better understanding, diagnosing, and treating stress-related disorders.
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Malysz J, Petkov GV. Urinary bladder smooth muscle ion channels: expression, function, and regulation in health and disease. Am J Physiol Renal Physiol 2020; 319:F257-F283. [PMID: 32628539 PMCID: PMC7473901 DOI: 10.1152/ajprenal.00048.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/21/2020] [Accepted: 06/28/2020] [Indexed: 12/17/2022] Open
Abstract
Urinary bladder smooth muscle (UBSM), also known as detrusor smooth muscle, forms the bladder wall and ultimately determines the two main attributes of the organ: urine storage and voiding. The two functions are facilitated by UBSM relaxation and contraction, respectively, which depend on UBSM excitability shaped by multiple ion channels. In this review, we summarize the current understanding of key ion channels establishing and regulating UBSM excitability and contractility. They include excitation-enhancing voltage-gated Ca2+ (Cav) and transient receptor potential channels, excitation-reducing K+ channels, and still poorly understood Cl- channels. Dynamic interplay among UBSM ion channels determines the overall level of Cav channel activity. The net Ca2+ influx via Cav channels increases global intracellular Ca2+ concentration, which subsequently triggers UBSM contractility. Here, for each ion channel type, we describe UBSM tissue/cell expression (mRNA and protein) profiles and their role in regulating excitability and contractility of UBSM in various animal species, including the mouse, rat, and guinea pig, and, most importantly, humans. The currently available data reveal certain interspecies differences, which complicate the translational value of published animal research results to humans. This review highlights recent developments, findings on genetic knockout models, pharmacological data, reports on UBSM ion channel dysfunction in animal bladder disease models, and the very limited human studies currently available. Among all gaps in present-day knowledge, the unknowns on expression and functional roles for ion channels determined directly in human UBSM tissues and cells under both normal and disease conditions remain key hurdles in the field.
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Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Urology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
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Kim SD, Cho KJ, Kim JC. Expression of cannabinoid 1 and, 2 receptors and the effects of cannabinoid 1 and, 2 receptor agonists on detrusor overactivity associated with bladder outlet obstruction in rats. BMC Urol 2017; 17:121. [PMID: 29284441 PMCID: PMC5747270 DOI: 10.1186/s12894-017-0313-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 12/20/2017] [Indexed: 12/21/2022] Open
Abstract
Background This study investigated changes in the expression of cannabinoid (CB) receptors and the effects of CB1 and CB2 agonists on detrusor overactivity (DO) associated with bladder outlet obstruction (BOO) in rats. Methods Male Sprague Dawley rats were randomly assigned to four groups (n = 10) in each group. The control group comprised sham-operated rats. A animals in the BOO, CB1 agonist and CB2 agonist groups all underwent BOO surgery. Three weeks postoperatively, cystometrography (CMG) was performed on all rats. After confirming the presence of DO in the CB1 and CB2 agonist groups, a CB1 agonist (WIN 55,212–2) and a CB2 agonist (CB65) were instilled intravesically, and CMG was repeated. CMG parameters, including the contraction interval (CI) and contraction pressure (CP) were then analyzed. The bladders of rats in all four groups were excised following CMG. Immunofluorescence staining and Western blotting were performed to localize CB1 and CB2 and measure their expression levels in the urothelium and detrusor muscle. Results The CI was significantly longer and the CP was significantly lower in the CB1 agonist group than in the BOO group. CI and CP in the CB2 agonist group showed the same results. CB1 receptor immunofluorescence staining signals and immunoreactive bands in Western blotting were increased in the BOO group compared with results in the control group. Similarly, results for the CB2 receptor were also increased in the BOO group, although this difference was not significant. The CMG parameters in the BOO group were significantly improved by the inhibitory effects of CB1 and CB2 agonists on BOO-associated DO. The expression of CB1 was significantly increased in the urothelium and detrusor muscle in BOO-associated DO, but no significant change in CB2 expression was observed. Conclusions CB1 and CB2 receptors, especially CB1, play a role in the pathophysiology of BOO-associated DO, and could serve as therapeutic targets.
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Affiliation(s)
- Sung Dae Kim
- Department of Urology, Graduate School of Medicine, Jeju National University, Jeju, South Korea
| | - Kang Jun Cho
- Department of Urology, Bucheon St. Mary's hospital, College of Medicine, The Catholic University of Korea, Sosa-Ro 327, Wonmi-gu, Bucheon-si, Gyeonggi-do, Seoul, 14647, South Korea
| | - Joon Chul Kim
- Department of Urology, Bucheon St. Mary's hospital, College of Medicine, The Catholic University of Korea, Sosa-Ro 327, Wonmi-gu, Bucheon-si, Gyeonggi-do, Seoul, 14647, South Korea.
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Yu G, Cheng M, Wang W, Zhao R, Liu Z. Involvement of WNK1-mediated potassium channels in the sexual dimorphism of blood pressure. Biochem Biophys Res Commun 2017; 485:255-260. [PMID: 28237360 DOI: 10.1016/j.bbrc.2017.02.098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 02/18/2017] [Indexed: 11/25/2022]
Abstract
Potassium homeostasis plays an essential role in the control of blood pressure. It is unknown, however, whether potassium balance is involved in the gender-associated blood pressure differences. We therefore investigated the possible mechanism of sexual dimorphism in blood pressure regulation by measuring the blood pressure, plasma potassium, renal actions of potassium channels and upstream regulator in male and female mice. Here we found that female mice exhibited lower blood pressure and higher plasma K+ level as compared to male littermates. Western blot analyses of mouse kidney extract revealed a significant decrease in renal outer medullary potassium (ROMK) channel expression, while large-conductance Ca2+-activated K+ (BK) channel and Na-K-2Cl cotransporter (NKCC2) as well as the upstream regulator with-no-lysine kinase 1 (WNK1) enhanced in female mice under normal condition. Surprisingly, both dietary K+ loading and K+ depletion eliminated the differences in plasma K+ and blood pressure between females and males, and the differences of renal K+ channels and WNK1 also attenuated in both groups of mice. These findings indicated the existence of a close correlation between K+ homeostasis and sex-associated blood pressure. Moreover, the differential regulation of ROMK, BK-α and NKCC2 between female and male mice, at least, were partly mediated via WNK1 pathway, which may contribute to the sexual dimorphism of plasma K+ and blood pressure control.
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Affiliation(s)
- Guofeng Yu
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325003, China
| | - Mengting Cheng
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325003, China
| | - Wei Wang
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325003, China
| | - Rong Zhao
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325003, China
| | - Zhen Liu
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325003, China.
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