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Alawadhi M, Kilarkaje N, Mouihate A, Al-Bader MD. Role of progesterone on dexamethasone-induced alterations in placental vascularization and progesterone receptors in rats†. Biol Reprod 2023; 108:133-149. [PMID: 36322157 DOI: 10.1093/biolre/ioac192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/04/2022] [Accepted: 10/18/2022] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Intrauterine growth restriction (IUGR) is manifested by lower maternal progesterone levels, smaller placental size, and decreased placental vascularity indicated by lower expression of vascular endothelial growth factor (VEGF). Studies showed that progesterone increases angiogenesis and induces VEGF expression in different tissues. Therefore, the aim of the present study is to evaluate the effect of progesterone on placental vascular bed and VEGF expression and the modulation of nuclear and membranous progesterone receptors (PR) in dexamethasone-induced rat IUGR model. METHODS Pregnant Sprague-Dawley rats were allocated into four groups and given intraperitoneal injections of either saline, dexamethasone, dexamethasone, and progesterone or progesterone. Injections started on gestation day (DG) 15 and lasted until the days of euthanization (19 and 21 DG). Enzyme-linked immunosorbent assay was used to evaluate plasma progesterone levels. Real-time PCR and western blotting were used to evaluate gene and protein expressions of VEGF, and PR in labyrinth and basal placental zones. Immunohistochemistry was used to locate VEGF and different PRs in placental cells. Immunofluorescence was used to monitor the expression of blood vessel marker (αSMA). RESULTS Dexamethasone decreased the vascular bed fraction and the expression of VEGF in both placental zones. Progesterone co-treatment with dexamethasone prevented this reduction. Nuclear and membrane PRs showed tissue-specific expression in different placental zones and responded differently to both dexamethasone and progesterone. CONCLUSIONS Progesterone treatment improves the outcomes in IUGR pregnancy. Progesterone alleviated DEX-induced IUGR probably by promoting placental VEGF and angiogenesis.
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Affiliation(s)
- Mariam Alawadhi
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Narayana Kilarkaje
- Department of Anatomy, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Abdeslam Mouihate
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Maie D Al-Bader
- Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
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Clinical Changes and Uterine Hemodynamic in Pyometra Medically Treated Bitches. Animals (Basel) 2020; 10:ani10112011. [PMID: 33142944 PMCID: PMC7693860 DOI: 10.3390/ani10112011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/29/2020] [Accepted: 10/30/2020] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Pyometra is an infectious uterine disorder marked by important clinical alterations and uterine contamination and blood flow changes in bitches. Although uterine removal is the most common mode of treatment, conservative therapy is an alternative. However, the success of medical treatment in restoring both clinical and uterine alterations has not yet been attested. Thus, we aimed to analyze the effects of both aglepristone alone or in combination with prostaglandin (associative) on clinical, laboratory and uterine hemodynamic features. Bitches were clinically and ultrasonographically (uterine blood flow) evaluated and medically followed-up throughout treatment (8 days) and castrated for local uterine analysis after 9 days of therapy onset. Associative therapy led to altered respiratory rate and decreased body temperature. Both treatments resolved bitches’ clinical condition and laboratory changes, and reduced uterine size. However, associative protocol was more effective in decreasing uterine vascularization and modulating uterine blood flow. Nevertheless, uterus remained microscopically altered soon after both therapy ending, thus not fully restoring local uterine changes in a short-term evaluation. Abstract Cystic endometrial hyperplasia–pyometra complex is a canine endometrial disorder, considered the most common and important among uterine diseases. The treatment of choice is ovariohysterectomy, but medical treatments have become an alternative. However, no studies have been performed in order to evaluate uterine hemodynamic changes during medical treatment for pyometra bitches. Therefore, the aim of this study was to compare the effectiveness of two medical protocols by means of clinical (heart rate, respiratory rate and body temperature), medullar response (complete blood count (CBC)) and uterine hemodynamic evaluation in pyometra bitches. For such purpose, 10 bitches with pyometra were assigned to two groups: Aglepristone Group (n = 5) and Associative Group (aglepristone + prostaglandin; n = 5). The Associative Group had altered respiratory rate and decreased body temperature. The Aglepristone Group had decreased plasma protein, however, leukocyte count reduced over time for both therapeutic protocols. Uterine area and vascularization score decreased throughout treatment. There was a significant reduction in uterine perimeter, area and vascularization score. The Associative Group had lower final diastolic velocity and higher systole:diastole ratio (S/D), pulsatility index (PI) and resistance index (RI). In conclusion, both medical treatments are effective in reversing clinical and CBC changes of pyometra, especially aglepristone, however they cannot fully restore local uterine changes in a short-term evaluation. Conversely, associative therapy was more effective in decreasing uterine vascularization and modulating uterine blood flow.
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Stanhewicz AE, Wenner MM, Stachenfeld NS. Sex differences in endothelial function important to vascular health and overall cardiovascular disease risk across the lifespan. Am J Physiol Heart Circ Physiol 2018; 315:H1569-H1588. [PMID: 30216121 DOI: 10.1152/ajpheart.00396.2018] [Citation(s) in RCA: 187] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Diseases of the cardiovascular system are the leading cause of morbidity and mortality in men and women in developed countries, and cardiovascular disease (CVD) is becoming more prevalent in developing countries. The prevalence of atherosclerotic CVD in men is greater than in women until menopause, when the prevalence of CVD increases in women until it exceeds that of men. Endothelial function is a barometer of vascular health and a predictor of atherosclerosis that may provide insights into sex differences in CVD as well as how and why the CVD risk drastically changes with menopause. Studies of sex differences in endothelial function are conflicting, with some studies showing earlier decrements in endothelial function in men compared with women, whereas others show similar age-related declines between the sexes. Because the increase in CVD risk coincides with menopause, it is generally thought that female hormones, estrogens in particular, are cardioprotective. Moreover, it is often proposed that androgens are detrimental. In truth, the relationships are more complex. This review first addresses female and male sex hormones and their receptors and how these interact with the cardiovascular system, particularly the endothelium, in healthy young women and men. Second, we address sex differences in sex steroid receptor-independent mechanisms controlling endothelial function, focusing on vascular endothelin and the renin-angiotensin systems, in healthy young women and men. Finally, we discuss sex differences in age-associated endothelial dysfunction, focusing on the role of attenuated circulating sex hormones in these effects.
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Affiliation(s)
- Anna E Stanhewicz
- Department of Kinesiology, Pennsylvania State University , University Park, Pennsylvania
| | - Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware , Newark, Delaware
| | - Nina S Stachenfeld
- The John B. Pierce Laboratory, New Haven, Connecticut.,Department of Obstetrics, Gynecology and Reproductive Sciences and Yale School of Public Health, Yale School of Medicine, New Haven, Connecticut
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Hulde N, Rogenhofer N, Brettner F, Eckert NC, Götzfried I, Nguyen T, Pagel JI, Kammerer T, Hofmann-Kiefer KF, Schelling G, Dendorfer A, Rehm M, Thaler CJ. The CYCLOCALYX study: Ovulatory cycle affects circulating compartments of the endothelial glycocalyx in blood. Am J Reprod Immunol 2017; 79. [DOI: 10.1111/aji.12767] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 08/31/2017] [Indexed: 12/24/2022] Open
Affiliation(s)
- Nikolai Hulde
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Nina Rogenhofer
- Division of Gynecological Endocrinology and Reproductive Medicine; Department of Gynecology and Obstetrics; Ludwig-Maximilians University; Munich Germany
| | - Florian Brettner
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Nicole C. Eckert
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Isabella Götzfried
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Thu Nguyen
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Judith-I. Pagel
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Tobias Kammerer
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | | | - Gustav Schelling
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Andreas Dendorfer
- Walter Brendel Zentrum; Ludwig-Maximilians University; Munich Germany
| | - Markus Rehm
- Department of Anesthesiology; Ludwig-Maximilians University; Munich Germany
| | - Christian J. Thaler
- Division of Gynecological Endocrinology and Reproductive Medicine; Department of Gynecology and Obstetrics; Ludwig-Maximilians University; Munich Germany
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Grossini E, Surico D, Mary DASG, Molinari C, Surico N, Vacca G. In anesthetized pigs human chorionic gonadotropin increases myocardial perfusion and function through a β-adrenergic-related pathway and nitric oxide. J Appl Physiol (1985) 2013; 115:422-35. [PMID: 23788572 DOI: 10.1152/japplphysiol.00425.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Human chorionic gonadotropin (hCG) is not only responsible for numerous pregnancy-related processes, but can affect the cardiovascular system as well. So far, however, information about any direct effect elicited by hCG on cardiac function, perfusion, and the mechanisms involved has remained scarce. Therefore, the present study aimed to determine the primary in vivo effect of hCG on cardiac contractility and coronary blood flow and the involvement of autonomic nervous system and nitric oxide (NO). Moreover, in coronary endothelial cells (CEC), the intracellular pathways involved in the effects of hCG on NO release were also examined. In 25 anesthetized pigs, intracoronary 500 mU/ml hCG infusion at constant heart rate and aortic blood pressure increased coronary blood flow, maximum rate of change of left ventricular systolic pressure, segmental shortening, cardiac output, and coronary NO release (P < 0.0001). These hemodynamic responses were graded in a further five pigs. Moreover, while blockade of muscarinic cholinoceptors (n = 5) and of α-adrenoceptors (n = 5) did not abolish the observed responses, β1-adrenoceptors blocker (n = 5) prevented the effects of hCG on cardiac function. In addition, β2-adrenoceptors (n = 5) and NO synthase inhibition (n = 5) abolished the coronary response and the effect of hCG on NO release. In CEC, hCG induced the phosphorylation of endothelial NO synthase through cAMP/PKA signaling and ERK1/2, Akt, p38 MAPK involvement, which were activated as downstream effectors of β2-adrenoceptor stimulation. In conclusion, in anesthetized pigs, hCG primarily increased cardiac function and perfusion through the involvement of β-adrenoceptors and NO release. Moreover, cAMP/PKA-dependent kinases phosphorylation was found to play a role in eliciting the observed NO production in CEC.
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Affiliation(s)
- Elena Grossini
- Physiology Laboratory, Department of Translational Medicine, University East Piedmont A. Avogadro, Novara, Italy.
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6
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HONNENS A, WEISSER S, WELTER H, EINSPANIER R, BOLLWEIN H. Relationships Between Uterine Blood Flow, Peripheral Sex Steroids, Expression of Endometrial Estrogen Receptors and Nitric Oxide Synthases During the Estrous Cycle in Mares. J Reprod Dev 2011; 57:43-8. [DOI: 10.1262/jrd.10-023t] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Aenne HONNENS
- Clinic for Cattle, School of Veterinary Medicine Hannover
| | - Simone WEISSER
- Clinic of Veterinary Gynaecology and Obstetrics, Faculty of Veterinary Medicine, University of Munich
| | - Harald WELTER
- Institute of Physiology, Technical University Munich
| | - Ralf EINSPANIER
- Institute of Veterinary Biochemistry, Freie Universitaet Berlin
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Nevo O, Soustiel JF, Thaler I. Maternal cerebral blood flow during normal pregnancy: a cross-sectional study. Am J Obstet Gynecol 2010; 203:475.e1-6. [PMID: 20599183 DOI: 10.1016/j.ajog.2010.05.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 03/18/2010] [Accepted: 05/19/2010] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Pregnancy is associated with substantial changes in the maternal circulatory physiology. Our aim was to investigate maternal cerebral blood flow (CBF) during normal pregnancies. STUDY DESIGN We prospectively measured maternal CBF in 210 low-risk pregnant women at different gestational ages, and in 15 nonpregnant women. CBF was assessed by measuring blood flow volume in the internal carotid artery (ICA) by dual-beam angle-independent digital Doppler ultrasound. RESULTS ICA blood flow volume increased during pregnancy from 318 mL/min ± 40.6 mL/min in the first trimester to 382.1 mL/min ± 50.0 mL/min during the third trimester, corresponding to CBF values of 44.4 and 51.8 mL/min(-1)/100 g(-1), respectively (P < .0001). CBF changes were associated with progressive decrease in cerebral vascular resistance and moderate increase in ICA diameter. CONCLUSION Maternal CBF is gradually increasing during normal pregnancy. Vasorelaxing impact of estrogens and other factors on cerebral vessels may explain the changes in CBF during pregnancy.
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Affiliation(s)
- Ori Nevo
- Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, University of Toronto, 60 Grosvenor Street, Toronto, Ontario, Canada.
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Nevo O, Soustiel JF, Thaler I. Cerebral blood flow is increased during controlled ovarian stimulation. Am J Physiol Heart Circ Physiol 2007; 293:H3265-9. [PMID: 17965286 DOI: 10.1152/ajpheart.00633.2007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Estrogen appears to enhance cerebral blood flow (CBF). An association between CBF and physiologically altered hormonal levels due to menstrual cycle, menopause, or exogenous manipulations such as ovariectomy or hormone replacement therapy has been demonstrated. The purpose of this study was to determine the association between ovarian stimulation and CBF in vivo by measuring blood flow in the internal carotid artery (ICA) after pituitary suppression and during controlled ovarian stimulation in women undergoing in vitro fertilization treatment cycles. ICA volume flows were measured by angle-independent dual-beam ultrasound Doppler in 12 women undergoing controlled ovarian stimulation. Measurements were performed after pituitary/ovarian suppression, in the late follicular phase, and at midluteal phase. Blood flow in the ICA increased by 22.2% and 32% in the late follicular and midluteal phases compared with the respective values obtained during ovarian suppression (P < 0.0005 and P < 0.0001, respectively). There was a significant correlation between increments in estrogen levels and increments in CBF when the late follicular phase was compared with the ovarian suppression period (r = 0.8, P < 0.001). Mean blood flow velocity significantly increased (by 15.7% and 16.9%, respectively) and cerebral vascular resistance significantly decreased (by 17.6% and 26.5%) during the late follicular and midluteal phases compared with respective measures during ovarian suppression. There was a significant correlation between an increase in estrogen levels and a decrease in cerebral vascular resistance when the late follicular phase was compared with the ovarian suppression period (r = -0.6, P < 0.05). These changes imply sex hormone-associated intracranial vasodilation leading to increased CBF during controlled ovarian stimulation.
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Affiliation(s)
- Ori Nevo
- Department of Obstetrics and Gynecology, Rambam Medical Center, Haifa, Israel 31096
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9
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Molinari C, Grossini E, Mary DASG, Uberti F, Ghigo E, Ribichini F, Surico N, Vacca G. Prolactin induces regional vasoconstriction through the beta2-adrenergic and nitric oxide mechanisms. Endocrinology 2007; 148:4080-90. [PMID: 17463060 DOI: 10.1210/en.2006-1577] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Prolactin has been associated with many effects and has been implicated in the pathogenesis of pregnancy-related hypertensive disorders, although little is known about its vascular effects. The present study was designed to determine the primary effect of prolactin on regional vascular beds and the mechanisms involved. In 37 anesthetized pigs, the infusion of 0.17 mug/kg min of prolactin at constant heart rate and arterial pressure decreased coronary, mesenteric, renal, and iliac blood flow. This response was graded in further five pigs by increasing the infused dose of the hormone between 0.017 and 1 mug/kg min. In 22 of the 37 pigs, blockade of cholinergic receptors (five pigs) and of alpha-adrenoceptors (five pigs) did not affect the prolactin-induced vascular response, which was abolished by blockade of beta(2)-adrenoceptors (five pigs) and by blockade of vascular nitric oxide (NO) synthase (seven pigs). In 15 of the 37 pigs the increases in measured blood flows caused by iv infusion of isoproterenol (five pigs) and by intraarterial administration of acetylcholine (five pigs) and of sodium nitroprusside (five pigs) were significantly reduced by infusion of prolactin. Moreover, the treatment of porcine aortic endothelial cells by prolactin caused a reduction of NO production and of the phosphorylation of ERK, Akt, and p38, which was prevented by the concomitant treatment by the beta(2)-adrenergic agonist albuterol. The present study showed that iv infusion of prolactin primarily caused coronary, mesenteric, renal, and iliac vasoconstriction. These effects were brought about by the inhibition of a vasodilatory beta(2)-adrenergic receptor-mediated effect related to the NO intracellular pathway.
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Affiliation(s)
- Claudio Molinari
- Laboratorio di Fisiologia, Dipartimento di Medicina Clinica e Sperimentale, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale A. Avogadro, via Solaroli 17, I-28100 Novara, Italy.
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10
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Molinari C, Grossini E, Mary DASG, Ribichini F, Surico N, Vacca G. The role of nitric oxide in the peripheral vasoconstriction caused by human placental lactogen in anaesthetized pigs. Exp Physiol 2006; 91:603-10. [PMID: 16513823 DOI: 10.1113/expphysiol.2005.032755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Regional intra-arterial infusion of human placental lactogen in anaesthetized pigs has been shown to cause coronary, renal and iliac vasoconstriction by antagonizing the vasodilatory effects of beta2-adrenergic receptors. Since nitric oxide is known to modulate or mediate beta2-adrenergic effects, the present study was planned in the same experimental model to determine the role of nitric oxide in the above vascular responses to human placental lactogen. In eight pigs anaesthetized with sodium pentobarbitone, changes in anterior descending coronary, left renal and left internal iliac blood flow caused by intra-arterial infusion of human placental lactogen at constant heart rate and arterial blood pressure were assessed using electromagnetic flowmeters. Intra-arterial infusion of the human placental lactogen caused decreases in coronary, renal and iliac blood flow which, respectively, averaged 16.7, 8.1 and 12.2% of the baseline values. The role of nitric oxide in this response was studied in the same pigs by repeating the experiments, after measured blood flows had returned to baseline values, following intra-arterial administration of N(omega)-nitro-L-arginine methyl ester (L-NAME). The subsequent intra-arterial infusion of human placental lactogen did not cause any significant changes in measured blood flows, even when performed after reversing the increase in arterial blood pressure and coronary, renal and iliac resistance caused by L-NAME with continuous intravenous infusion of papaverine. These results indicate that the coronary, renal and iliac vasoconstriction caused by human placental lactogen, known to involve antagonism of beta2-adrenergic vasodilatory effects, was mediated by inhibition of nitric oxide release.
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Affiliation(s)
- C Molinari
- Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale A. Avogadro, via Solaroli 17, I-28100 Novara, Italy.
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Grossini E, Molinari C, Battaglia A, Mary DASG, Ribichini F, Surico N, Vacca G. Human Placental Lactogen Decreases Regional Blood Flow in Anesthetized Pigs. J Vasc Res 2006; 43:205-13. [PMID: 16410683 DOI: 10.1159/000090950] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Accepted: 11/02/2005] [Indexed: 11/19/2022] Open
Abstract
In 22 pigs anesthetized with sodium pentobarbitone, changes in blood flow caused by infusion of human placental lactogen into the left renal, external iliac, and anterior descending coronary arteries were assessed using electromagnetic flowmeters. In 17 pigs, infusion of human placental lactogen whilst keeping the heart rate and arterial pressure constant decreased coronary, renal and iliac flow. In 5 additional pigs, increasing the dose of human placental lactogen produced a dose-related decrease in regional blood flow. The mechanisms of the above response were studied in 15 of the 17 pigs by repeating the experiment of infusion. The human placental lactogen-induced decrease in regional blood flow was not affected by blockade of cholinergic receptors (5 pigs) or of alpha-adrenergic receptors (5 pigs), but it was abolished by blockade of beta2-adrenergic receptors (5 pigs). The present study showed that intra-arterial infusion of human placental lactogen primarily decreased coronary, renal and iliac blood flow. The mechanism of this response was shown to be due to the inhibition of a vasodilatory beta2-adrenergic receptor-mediated effect.
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Affiliation(s)
- E Grossini
- Laboratorio di Fisiologia, Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale 'A. Avogadro', Novara, Italy.
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12
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Au ALS, Kwok CC, Lee ATC, Kwan YW, Lee MMS, Zhang RZ, Ngai SM, Lee SMY, He GW, Fung KP. Activation of iberiotoxin-sensitive, Ca2+-activated K+ channels of porcine isolated left anterior descending coronary artery by diosgenin. Eur J Pharmacol 2004; 502:123-33. [PMID: 15464098 DOI: 10.1016/j.ejphar.2004.08.045] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 08/11/2004] [Accepted: 08/19/2004] [Indexed: 11/26/2022]
Abstract
The objective of this study was to determine the vasodilating effect of 3beta-hydroxy-5-spirostene (diosgenin), a phytoestrogen found in wild yams, using porcine resistance left anterior descending coronary artery. In 5-hydroxytryptamine (3 microM) pre-contracted preparation, diosgenin caused a concentration-dependent (0.01 to 1 microM), endothelium-independent relaxation, with a maximum relaxation of approximately 72% at 1 microM. No apparent effect was observed with 17beta-oestradiol and progesterone with concentrations < or =0.3 microM, and a relaxation of approximately 15% and approximately 23% caused by 17beta-oestradiol (1 microM) and progesterone (1 microM), respectively. Diosgenin-elicited relaxation was not altered by 7alpha,17beta-[9[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17-diol (ICI 182,780), mifepristone, (+)-bicuculline, cis-N-(2-phenylcyclopentyl)azacyclotridec-1-en-2-amine (MDL 12330A), glibenclamide and scavengers of reactive oxygen species. The iberiotoxin-sensitive, Ca2+-activated K+ (BK(Ca)) current of single vascular myocytes recorded, using patch-clamp techniques, was markedly enhanced by diosgenin, 17beta-oestradiol and progesterone. Application of (9S, 10R, 12R)-2,3,9,10,11,12-hexahydro-10-methoxy-2,9-dimethyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester (KT 5823, 300 nM) eradicated the enhancement of BK(Ca) amplitude. Diosgenin, 17beta-oestradiol and progesterone did not affect whereas phloretin, biochanin A and zearalanone (1 microM each) significantly suppressed [Ca2+]o-induced contraction. In oestrogen competition essay using human breast cancer cell (MCF-7 cells), diosgenin (0.001 nM to 10 microM) did not interact with oestrogen receptor-alpha, and no displacement of [3H]17beta-oestradiol was observed. In oestrogen receptor alpha- and beta-fluorescence polarization competitor assay, diosgenin (100 microM) demonstrated a greater competition with the beta-isoform of oestrogen receptor. These results suggest that diosgenin caused an acute, endothelium-independent coronary artery relaxation via protein kinase G signalling cascade and an activation of BK(Ca) channel of arterial smooth muscle cells. The oestrogen receptor (alpha and beta-isoforms) and progesterone receptor are probably not involved.
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Affiliation(s)
- Alice Lai Shan Au
- Room 409B, Basic Medical Sciences Building, Department of Pharmacology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
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Abstract
'Classical' genomic progesterone receptors appear relatively late in phylogenesis, i.e. it is only in birds and mammals that they are detectable. In the different species, they mediate manifold effects regarding the differentiation of target organ functions, mainly in the reproductive system. Surprisingly, we know little about the physiology, endocrinology, and pharmacology of progesterone and progestins in male gender or men respectively, despite the fact that, as to progesterone secretion and serum progesterone levels, there are no great quantitative differences between men and women (at least outside the luteal phase). In a prospective cohort study of 1026 men with and without cardiovascular disease, we were not able to demonstrate any age-dependent change in serum progesterone concentrations. Progesterone influences spermiogenesis, sperm capacitation/acrosome reaction and testosterone biosynthesis in the Leydig cells. Other progesterone effects in men include those on the central nervous system (CNS) (mainly mediated by 5alpha-reduced progesterone metabolites as so-called neurosteroids), including blocking of gonadotropin secretion, sleep improvement, and effects on tumors in the CNS (meningioma, fibroma), as well as effects on the immune system, cardiovascular system, kidney function, adipose tissue, behavior, and respiratory system. A progestin may stimulate weight gain and appetite in men as well as in women. The detection of progesterone receptor isoforms would have a highly diagnostic value in prostate pathology (benign prostatic hypertrophy and prostate cancer). The modulation of progesterone effects on typical male targets is connected with a great pharmacodynamic variability. The reason for this is that, in men, some important effects of progesterone are mediated non-genomically through different molecular biological modes of action. Therefore, the precise therapeutic manipulation of progesterone actions in the male requires completely new endocrine-pharmacological approaches.
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Grossini E, Battaglia A, Bona G, Mary DASG, Molinari C, Vacca G. The effects of insulin on mesenteric blood flow in anaesthetized pigs. Exp Physiol 2004; 89:363-71. [PMID: 15123556 DOI: 10.1113/expphysiol.2004.027334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Infusion of insulin in anaesthetized pigs has been shown to cause an increase in renal blood flow and a decrease in coronary blood flow, which were the net result of a vasoconstriction involving sympathetic alpha-adrenoceptor-mediated mechanisms and of a local vasodilatation involving the endothelial release of nitric oxide. In the present study, the effect of insulin on superior mesenteric blood flow was examined in pentobarbitone-anaesthetized pigs at constant heart rate, aortic blood pressure, left ventricular contractility and blood levels of glucose and potassium. In 10 pigs, infusion of 0.004 IU kg(-1) min(-1) of insulin increased mesenteric flow. In five of these pigs, intravenous phentolamine enhanced the increase in mesenteric flow elicited by insulin, a response which was abolished by the subsequent injection of N(omega)-nitro-L-arginine methyl ester (L-NAME) into the mesenteric artery. In the remaining five pigs, infusion of insulin after intramesenteric injection of L-NAME caused a decrease in mesenteric flow. This response was abolished by the subsequent intravenous administration of phentolamine. The present study showed that infusion of insulin in anaesthetized pigs primarily caused a mesenteric vasodilatation, which was the net result of two opposite effects, namely a predominant vasodilatation mediated by the endothelial release of nitric oxide and a sympathetic vasoconstrictor mechanism mediated by alpha-adrenoceptors.
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Affiliation(s)
- E Grossini
- Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale 'A. Avogadro', Novara, Italy.
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Molinari C, Battaglia A, Grossini E, Mary DASG, Vassanelli C, Vacca G. The effect of dehydroepiandrosterone on regional blood flow in prepubertal anaesthetized pigs. J Physiol 2004; 557:307-19. [PMID: 15034120 PMCID: PMC1665037 DOI: 10.1113/jphysiol.2004.063354] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Dehydroepiandrosterone has been implicated in vascular disease and its associated insulin resistance and hypertension, though little is known about its vascular effects. We have recently shown in prepubertal anaesthetized pigs that intravenous infusion of dehydroepiandrosterone caused coronary vasoconstriction through the inhibition of a vasodilatory beta-adrenergic receptor-mediated effect related to the release of nitric oxide. The present study was designed to investigate the effect of dehydroepiandrosterone on mesenteric, renal and iliac vascular beds. In prepubertal pigs of both sexes anaesthetized with sodium pentobarbitone, changes in superior mesenteric, left renal and left external iliac blood flow caused by intravenous infusion of dehydroepiandrosterone were assessed using electromagnetic flowmeters. Changes in heart rate and arterial blood pressure were prevented by atrial pacing and by connecting the arterial system to a pressurized reservoir containing Ringer solution. In 22 pigs, infusion of 1 mg h(-1) of dehydroepiandrosterone decreased mesenteric, renal and iliac blood flow. In a further 10 pigs, dose-response curves were obtained by graded increases in the infused dose of hormone between 0.03 and 4 mg h(-1). The mechanisms of the above response were studied in the 22 pigs by repeating the experiment after haemodynamic variables had returned to the control values observed before infusion. Blockade of alpha-adrenoceptors with intravenous phentolamine (five pigs) did not affect the dehydroepiandrosterone-induced mesenteric, renal and iliac vasoconstriction. This response was abolished by blockade of beta(2)-adrenoceptors with intravenous butoxamine (five pigs) and by blockade of mesenteric, renal and iliac nitric oxide synthase with intra-arterial administration of N(omega)-nitro-L-arginine methyl ester (seven pigs), even after reversing the increase in local vascular resistance caused by the two blocking agents with intravenous infusion of papaverine. In five pigs, the increase in measured blood flow caused by intravenous infusion of isoproterenol (isoprenaline) was significantly reduced by infusion of dehydroepiandrosterone. The present study showed that intravenous infusion of dehydroepiandrosterone primarily caused mesenteric, renal and iliac vasoconstriction. The mechanisms of this response were shown to be due to the inhibition of a vasodilatory beta(2)-adrenergic receptor-mediated effect, which possibly involved the release of nitric oxide.
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Affiliation(s)
- C Molinari
- Laboratorio di Fisiologia, Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale A. Avogadro, Novara, Italy.
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Molinari C, Battaglia A, Grossini E, Mary DASG, Vassanelli C, Vacca G. The effect of testosterone on regional blood flow in prepubertal anaesthetized pigs. J Physiol 2002; 543:365-72. [PMID: 12181306 PMCID: PMC2290490 DOI: 10.1113/jphysiol.2002.022756] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This work was undertaken to study the effects of testosterone on the coronary, mesenteric, renal and iliac circulations and to determine the mechanisms of action involved. In prepubertal pigs of both sexes anaesthetized with sodium pentobarbitone, changes in left circumflex or anterior descending coronary, superior mesenteric, left renal and left external iliac blood flow caused by intra-arterial infusion of testosterone were assessed using electromagnetic flowmeters. Changes in heart rate and arterial blood pressure were prevented by atrial pacing and by connecting the arterial system to a pressurized reservoir containing Ringer solution. In 12 pigs, intra-arterial infusion of testosterone for 5 min to achieve a stable intra-arterial concentration of 1 microg l(-1) increased coronary, mesenteric, renal and iliac blood flow without affecting the maximum rate of change of left ventricular systolic pressure (left ventricular dP/dt(max)) and filling pressures of the heart. In a further five pigs, a concentration-response curve was obtained by graded increases in the intra-arterial concentration of the hormone between 0.125 and 8 microg l(-1). The mechanisms of these responses were studied in the 12 pigs by repeating the experiment after haemodynamic variables had returned to the control values before infusions. In six pigs, blockade of muscarinic cholinoceptors and adrenoceptors with atropine, propranolol and phentolamine did not affect the responses caused by intra-arterial infusion of testosterone performed to achieve a stable intra-arterial concentration of 1 microg l(-1). In the same pigs and in the remaining six pigs, the increases in coronary, mesenteric, renal and iliac blood flow caused by intra-arterial infusion of testosterone performed to achieve a stable intra-arterial concentration of 1 microg l(-1) were prevented by intra-arterial injection of N(omega)-nitro-L-arginine methyl ester. The present study shows that intra-arterial infusion of testosterone dilated coronary, mesenteric, renal and iliac circulations. The mechanism of this response involved the release of nitric oxide.
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Affiliation(s)
- C Molinari
- Laboratorio di Fisiologia, Dipartimento di Scienze Mediche, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale A. Avogadro, via Solaroli 17, I-28100 Novara, Italy.
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