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Zaccarelli-Magalhães J, Manes M, Féba LS, Abreu GR, Flório JC, Ricci EL, Felício LF, Spinosa HS. Do Autistic and Depressed Rats Express the Same Type of Maternal Care? Neuroscience 2024; 536:72-78. [PMID: 38000546 DOI: 10.1016/j.neuroscience.2023.11.024] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 11/17/2023] [Accepted: 11/20/2023] [Indexed: 11/26/2023]
Abstract
Autism is a neurodevelopmental disorder that is more frequently diagnosed in men. Nevertheless, through current diagnostic tools, women have also been found to be affected by this disorder, but in different ways. Few studies have been conducted regarding unique periods of life, such as motherhood. Yet, extant literature has already described the existence of a comorbidity between autism and postpartum depression. Thus, this study aimed to compare the maternal care sphere between two animal models of these diseases. Lactating rats were subdivided into three groups (n = 8 animals/group): 1) control dams; 2) maternal separation (MS) dams, separated from their litter for 3 h daily from lactating day (LD) 2-12 for postpartum depression induction; and 3) valproic acid (VPA) dams, which were the pups of dams treated with 400 mg/kg of VPA (i.p.) on gestational day 12.5 for autism induction. Maternal care tests were performed during lactation and, after weaning, dams were euthanized for the analysis of dopaminergic system on the prefrontal cortex. The results showed an impairment of maternal care of MS dams and an improvement of VPA dams, as well as alterations on dopaminergic system that corroborates the behavior data. These findings indicate that VPA dams express better maternal care, even with cognitive and socialization difficulties. This is probably due to a hyper-focus, as opposed to MS dams, which mimic the maternal care dysfunction expressed by women with postpartum depression.
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Affiliation(s)
- J Zaccarelli-Magalhães
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil.
| | - M Manes
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil
| | - L S Féba
- Health Science Institute, Presbyterian Mackenzie University, Rua da Consolação, 930, 01302-907 São Paulo, Brazil
| | - G R Abreu
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil
| | - J C Flório
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil
| | - E L Ricci
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil; Health Science Institute, Presbyterian Mackenzie University, Rua da Consolação, 930, 01302-907 São Paulo, Brazil; School of Health Sciences IGESP, Rua da Consolação, 1025, 01301-000 São Paulo, Brazil
| | - L F Felício
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil
| | - H S Spinosa
- Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Avenida Professor Doutor Orlando Marques de Paiva, 87, 05508-270 São Paulo, Brazil
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Claudio ERG, Almeida SA, Mengal V, Brasil GA, Santuzzi CH, Tiradentes RV, Gouvea SA, Bissoli NS, Santos RL, Abreu GR. Swimming training prevents coronary endothelial dysfunction in ovariectomized spontaneously hypertensive rats. ACTA ACUST UNITED AC 2017; 50:e5495. [PMID: 28099583 PMCID: PMC5264533 DOI: 10.1590/1414-431x20165495] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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] [Received: 06/17/2016] [Accepted: 11/10/2016] [Indexed: 11/22/2022]
Abstract
Estrogen deficiency and hypertension are considered major risk factors for the
development of coronary heart disease. On the other hand, exercise training is
considered an effective form to prevent and treat cardiovascular diseases. However,
the effects of swimming training (SW) on coronary vascular reactivity in female
ovariectomized hypertensive rats are not known. We aimed to evaluate the effects of
SW on endothelium-dependent coronary vasodilation in ovariectomized hypertensive
rats. Three-month old spontaneously hypertensive rats (SHR, n=50) were divided into
four groups: sham (SH), sham plus swimming training (SSW), ovariectomized (OVX), and
ovariectomized plus swimming training (OSW). The SW protocol (5 times/week, 60
min/day) was conducted for 8 weeks. The vasodilatory response was measured in
isolated hearts in the absence and presence of a nitric oxide synthase inhibitor
(L-NAME, 100 µM). Cardiac oxidative stress was evaluated in situ by
dihydroethidium fluorescence, while the expression of antioxidant enzymes (SOD-2 and
catalase) and their activities were assessed by western blotting and
spectrophotometry, respectively. Vasodilation in SHR was significantly reduced by
OVX, even in the presence of L-NAME, in conjunction with an increased oxidative
stress. These effects were prevented by SW, and were associated with a decrease in
oxidative stress. Superoxide dismutase 2 (SOD-2) and catalase expression increased
only in the OSW group. However, no significant difference was found in the activity
of these enzymes. In conclusion, SW prevented the endothelial dysfunction in the
coronary bed of ovariectomized SHR associated with an increase in the expression of
antioxidant enzymes, and therefore may prevent coronary heart disease in hypertensive
postmenopausal women.
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Affiliation(s)
- E R G Claudio
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - S A Almeida
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - V Mengal
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - G A Brasil
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - C H Santuzzi
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - R V Tiradentes
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - S A Gouvea
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - N S Bissoli
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - R L Santos
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - G R Abreu
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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Borgo MV, Claudio ERG, Silva FB, Romero WG, Gouvea SA, Moysés MR, Santos RL, Almeida SA, Podratz PL, Graceli JB, Abreu GR. Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats. ACTA ACUST UNITED AC 2016; 49:e4655. [PMID: 26577845 PMCID: PMC4678653 DOI: 10.1590/1414-431x20154655] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [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] [Received: 01/16/2015] [Accepted: 06/29/2015] [Indexed: 02/07/2023]
Abstract
Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces
blood pressure in hypertensive women. However, the effects of DRSP on
endothelium-dependent coronary vasodilation have not been evaluated. This study
investigated the effects of combined therapy with estrogen (E2) and DRSP on
endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX)
spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12
weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with
E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters
were directly evaluated by catheter insertion into the femoral artery.
Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial
bed was assessed using isolated hearts according to a modified Langendorff method.
Coronary protein expression of endothelial nitric oxide synthase and estrogen
receptor alpha (ER-α) was assessed by Western blotting. Histological slices of
coronary arteries were stained with hematoxylin and eosin, and morphometric
parameters were analyzed. Oxidative stress was assessed in situ by
dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which
was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial
dysfunction, which was prevented by both treatments. However, the vasodilator
response in the E2+DRSP group was significantly higher at the three highest
concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was
restored by both treatments. Morphometric parameters and oxidative stress were
augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2
and DRSP may be an important therapeutic option in the prevention of coronary heart
disease in hypertensive post-menopausal women.
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Affiliation(s)
- M V Borgo
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - E R G Claudio
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - F B Silva
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - W G Romero
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - S A Gouvea
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - M R Moysés
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - R L Santos
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - S A Almeida
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
| | - P L Podratz
- Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - J B Graceli
- Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - G R Abreu
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal de Espírito Santo, Vitória, ES, Brasil
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4
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Dalpiaz PLM, Lamas AZ, Caliman IF, Ribeiro RF, Abreu GR, Moyses MR, Andrade TU, Gouvea SA, Alves MF, Carmona AK, Bissoli NS. Sex Hormones Promote Opposite Effects on ACE and ACE2 Activity, Hypertrophy and Cardiac Contractility in Spontaneously Hypertensive Rats. PLoS One 2015; 10:e0127515. [PMID: 26010093 PMCID: PMC4444272 DOI: 10.1371/journal.pone.0127515] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 04/16/2015] [Indexed: 11/25/2022] Open
Abstract
Background There is growing interest in sex differences and RAS components. However, whether gender influences cardiac angiotensin I-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity is still unknown. In the present work, we determined the relationship between ACE and ACE2 activity, left ventricular function and gender in spontaneously hypertensive rats (SHRs). Methodology / Principal Findings Twelve-week-old female (F) and male (M) SHRs were divided into 2 experimental groups (n = 7 in each group): sham (S) and gonadectomized (G). Fifty days after gonadectomy, we measured positive and negative first derivatives (dP/dt maximum left ventricle (LV) and dP/dt minimum LV, respectively), hypertrophy (morphometric analysis) and ACE and ACE2 catalytic activity (fluorimetrically). Expression of calcium handling proteins was measured by western blot. Male rats exhibited higher cardiac ACE and ACE2 activity as well as hypertrophy compared to female rats. Orchiectomy decreased the activity of these enzymes and hypertrophy, while ovariectomy increased hypertrophy and ACE2, but did not change ACE activity. For cardiac function, the male sham group had a lower +dP/dt than the female sham group. After gonadectomy, the +dP/dt increased in males and reduced in females. The male sham group had a lower -dP/dt than the female group. After gonadectomy, the -dP/dt increased in the male and decreased in the female groups when compared to the sham group. No difference was observed among the groups in SERCA2a protein expression. Gonadectomy increased protein expression of PLB (phospholamban) and the PLB to SERCA2a ratio in female rats, but did not change in male rats. Conclusion Ovariectomy leads to increased cardiac hypertrophy, ACE2 activity, PLB expression and PLB to SERCA2a ratio, and worsening of hemodynamic variables, whereas in males the removal of testosterone has the opposite effects on RAS components.
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Affiliation(s)
- P. L. M. Dalpiaz
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
- * E-mail:
| | - A. Z. Lamas
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
| | - I. F. Caliman
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
| | - R. F. Ribeiro
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
| | - G. R. Abreu
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
| | - M. R. Moyses
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
| | - T. U. Andrade
- Department of Pharmacy, University Vila Velha, Vila Velha, Espirito Santo, Brazil
| | - S. A. Gouvea
- Nucleus of Biotechnology, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
| | - M. F. Alves
- Department of Biophysics, Escola Paulista de Medicina, Federal University of São Paulo, São Paulo, Brazil
| | - A. K. Carmona
- Department of Biophysics, Escola Paulista de Medicina, Federal University of São Paulo, São Paulo, Brazil
| | - N. S. Bissoli
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Espirito Santo, Brazil
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Silva FB, Romero WG, Carvalho ALR, Borgo MV, Amorim MHC, Gouvea SA, Abreu GR. Hormone therapy with tamoxifen reduces plasma levels of NT-B-type natriuretic peptide but does not change ventricular ejection fraction after chemotherapy in women with breast cancer. ACTA ACUST UNITED AC 2014; 48:154-60. [PMID: 25424369 PMCID: PMC4321221 DOI: 10.1590/1414-431x20144189] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [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] [Received: 06/15/2014] [Accepted: 09/17/2014] [Indexed: 12/16/2022]
Abstract
The objective of this study was to evaluate the effect of tamoxifen on the plasma
concentration of NT-pro-B-type natriuretic peptide (NT-proBNP) in women undergoing
chemotherapy for breast cancer and to correlate changes in NT-proBNP with the left
ventricular ejection fraction (LVEF). Over a period of 12 months, we followed 60
women with a diagnosis of breast cancer. The patients were separated into a group
that received only chemotherapy (n=23), a group that received chemotherapy +
tamoxifen (n=21), and a group that received only tamoxifen (n=16). Plasma levels of
NT-proBNP were assessed at 0 (T0), 6 (T6), and 12 (T12) months of treatment, and
echocardiography data were assessed at T0 and T12. Plasma NT-proBNP levels were
increased in the chemotherapy-only group at T6 and T12, whereas elevated NT-proBNP
levels were only found at T6 in the chemotherapy + tamoxifen group. At T12, the
chemotherapy + tamoxifen group exhibited a significant reduction in the peptide to
levels similar to the group that received tamoxifen alone. The chemotherapy-only
group exhibited a significant decrease in LVEF at T12, whereas the chemotherapy +
tamoxifen and tamoxifen-only groups maintained levels similar to those at the
beginning of treatment. Treatment with tamoxifen for 6 months after chemotherapy
significantly reduced the plasma levels of NT-proBNP and did not change LVEF in women
with breast cancer.
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Affiliation(s)
- F B Silva
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - W G Romero
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - A L R Carvalho
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - M V Borgo
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - M H C Amorim
- Departamento de Enfermagem, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - S A Gouvea
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - G R Abreu
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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Santuzzi CH, Tiradentes RV, Mengal V, Claudio ERG, Mauad H, Gouvea SA, Abreu GR. Combined aliskiren and L-arginine treatment has antihypertensive effects and prevents vascular endothelial dysfunction in a model of renovascular hypertension. ACTA ACUST UNITED AC 2014; 48:65-76. [PMID: 25493385 PMCID: PMC4288495 DOI: 10.1590/1414-431x20144191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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] [Received: 06/12/2014] [Accepted: 09/09/2014] [Indexed: 02/07/2023]
Abstract
Angiotensin II is a key player in the pathogenesis of renovascular hypertension, a
condition associated with endothelial dysfunction. We investigated aliskiren (ALSK)
and L-arginine treatment both alone and in combination on blood pressure (BP), and
vascular reactivity in aortic rings. Hypertension was induced in 40 male Wistar rats
by clipping the left renal artery. Animals were divided into Sham, 2-kidney, 1-clip
(2K1C) hypertension, 2K1C+ALSK (ALSK), 2K1C+L-arginine (L-arg), and
2K1C+ALSK+L-arginine (ALSK+L-arg) treatment groups. For 4 weeks, BP was monitored and
endothelium-dependent and independent vasoconstriction and relaxation were assessed
in aortic rings. ALSK+L-arg reduced BP and the contractile response to phenylephrine
and improved acetylcholine relaxation. Endothelium removal and incubation with
N-nitro-L-arginine methyl ester (L-NAME) increased the response to phenylephrine in
all groups, but the effect was greater in the ALSK+L-arg group. Losartan reduced the
contractile response in all groups, apocynin reduced the contractile response in the
2K1C, ALSK and ALSK+L-arg groups, and incubation with superoxide dismutase reduced
the phenylephrine response in the 2K1C and ALSK groups. eNOS expression increased in
the 2K1C and L-arg groups, and iNOS was increased significantly only in the 2K1C
group compared with other groups. AT1 expression increased in the 2K1C
compared with the Sham, ALSK and ALSK+L-arg groups, AT2 expression
increased in the ALSK+L-arg group compared with the Sham and L-arg groups, and
gp91phox decreased in the ALSK+L-arg group compared with the 2K1C and ALSK groups. In
conclusion, combined ALSK+L-arg was effective in reducing BP and preventing
endothelial dysfunction in aortic rings of 2K1C hypertensive rats. The responsible
mechanisms appear to be related to the modulation of the local renin-angiotensin
system, which is associated with a reduction in endothelial oxidative stress.
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Affiliation(s)
- C H Santuzzi
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - R V Tiradentes
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - V Mengal
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - E R G Claudio
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - H Mauad
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - S A Gouvea
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
| | - G R Abreu
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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7
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Graceli JB, Cicilini MA, Bissoli NS, Abreu GR, Moysés MR. Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney. Braz J Med Biol Res 2013; 46:521-7. [PMID: 23828583 PMCID: PMC3854445 DOI: 10.1590/1414-431x20132666] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [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] [Received: 10/29/2012] [Accepted: 03/20/2013] [Indexed: 11/21/2022] Open
Abstract
The maintenance of extracellular Na+ and Cl- concentrations
in mammals depends, at least in part, on renal function. It has been shown that
neural and endocrine mechanisms regulate extracellular fluid volume and
transport of electrolytes along nephrons. Studies of sex hormones and renal
nerves suggested that sex hormones modulate renal function, although this
relationship is not well understood in the kidney. To better understand the role
of these hormones on the effects that renal nerves have on Na+ and
Cl- reabsorption, we studied the effects of renal denervation and
oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol
benzoate (OVE, 2.0 mg·kg-1·day-1, sc) and
progesterone (OVP, 1.7 mg·kg-1·day-1,
sc). We assessed Na+ and Cl- fractional
excretion (FENa+ and FECl-, respectively) and renal and plasma catecholamine release concentrations.
FENa+, FECl-, water intake, urinary flow, and renal and plasma catecholamine release
levels increased in OVX vs control rats. These effects were
reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation
did not alter FENa+, FECl-, water intake, or urinary flow values vs controls.
However, the renal catecholamine release level was decreased in the OVP
(236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2;
ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased
renal catecholamine release levels compared to either treatment alone. OVE
normalized and OVP reduced renal catecholamine release levels, and the effects
on plasma catecholamine release levels were reversed by ODE and ODP replacement
in OD. These data suggest that progesterone may influence catecholamine release
levels by renal innervation and that there are complex interactions among renal
nerves, estrogen, and progesterone in the modulation of renal function.
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Affiliation(s)
- J B Graceli
- Departamento de Morfologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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8
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Dalpiaz PLM, Lamas AZ, Caliman IF, Medeiros ARS, Abreu GR, Moysés MR, Andrade TU, Alves MF, Carmona AK, Bissoli NS. The chronic blockade of angiotensin I-converting enzyme eliminates the sex differences of serum cytokine levels of spontaneously hypertensive rats. Braz J Med Biol Res 2013; 46:171-7. [PMID: 23369979 PMCID: PMC3854361 DOI: 10.1590/1414-431x20122472] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [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] [Received: 07/07/2012] [Accepted: 10/18/2012] [Indexed: 11/22/2022] Open
Abstract
Sex hormones modulate the action of both cytokines and the renin-angiotensin system. However, the effects of angiotensin I-converting enzyme (ACE) on the proinflammatory and anti-inflammatory cytokine levels in male and female spontaneously hypertensive rats (SHR) are unclear. We determined the relationship between ACE activity, cytokine levels and sex differences in SHR. Female (F) and male (M) SHR were divided into 4 experimental groups each (n = 7): sham + vehicle (SV), sham + enalapril (10 mg/kg body weight by gavage), castrated + vehicle, and castrated + enalapril. Treatment began 21 days after castration and continued for 30 days. Serum cytokine levels (ELISA) and ACE activity (fluorimetry) were measured. Male rats exhibited a higher serum ACE activity than female rats. Castration reduced serum ACE in males but did not affect it in females. Enalapril reduced serum ACE in all groups. IL-10 (FSV = 16.4 ± 1.1 pg/mL; MSV = 12.8 ± 1.2 pg/mL), TNF-α (FSV = 16.6 ± 1.2 pg/mL; MSV = 12.8 ± 1 pg/mL) and IL-6 (FSV = 10.3 ± 0.2 pg/mL; MSV = 7.2 ± 0.2 pg/mL) levels were higher in females than in males. Ovariectomy reduced all cytokine levels and orchiectomy reduced IL-6 but increased IL-10 concentrations in males. Castration eliminated the differences in all inflammatory cytokine levels (IL-6 and TNF-α) between males and females. Enalapril increased IL-10 in all groups and reduced IL-6 in SV rats. In conclusion, serum ACE inhibition by enalapril eliminated the sexual dimorphisms of cytokine levels in SV animals, which suggests that enalapril exerts systemic anti-inflammatory and anti-hypertensive effects.
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Affiliation(s)
- P L M Dalpiaz
- Universidade Federal do Espírito Santo, Departamento de Ciências Fisiológicas, Vitória, ES, Brasil
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9
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Santuzzi CH, Futuro Neto HA, Pires JGP, Gonçalves WLS, Tiradentes RV, Gouvea SA, Abreu GR. Sertraline inhibits formalin-induced nociception and cardiovascular responses. Braz J Med Biol Res 2011; 45:43-8. [PMID: 22086464 PMCID: PMC3854144 DOI: 10.1590/s0100-879x2011007500154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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] [Received: 05/01/2011] [Accepted: 10/31/2011] [Indexed: 12/22/2022] Open
Abstract
The objective of the present study was to determine the antihyperalgesic effect of sertraline, measured indirectly by the changes of sciatic afferent nerve activity, and its effects on cardiorespiratory parameters, using the model of formalin-induced inflammatory nociception in anesthetized rats. Serum serotonin (5-HT) levels were measured in order to test their correlation with the analgesic effect. Male Wistar rats (250-300 g) were divided into 4 groups (N = 8/per group): sertraline-treated group (Sert + Saline (Sal) and Sert + Formalin (Form); 3 mg·kg-1·day-1, ip, for 7 days) and saline-treated group (Sal + Sal and Sal + Form). The rats were injected with 5% (50 µL) formalin or saline into the right hind paw. Sciatic nerve activity was recorded using a silver electrode connected to a NeuroLog apparatus, and cardiopulmonary parameters (mean arterial pressure, heart rate and respiratory frequency), assessed after arterial cannulation and tracheotomy, were monitored using a Data Acquisition System. Blood samples were collected from the animals and serum 5-HT levels were determined by ELISA. Formalin injection induced the following changes: sciatic afferent nerve activity (+50.8 ± 14.7%), mean arterial pressure (+1.4 ± 3 mmHg), heart rate (+13 ± 6.8 bpm), respiratory frequency (+4.6 ± 5 cpm) and serum 5-HT increased to 1162 ± 124.6 ng/mL. Treatment with sertraline significantly reduced all these parameters (respectively: +19.8 ± 6.9%, -3.3 ± 2 mmHg, -13.1 ± 10.8 bpm, -9.8 ± 5.7 cpm) and serum 5-HT level dropped to 634 ± 69 ng/mL (P < 0.05). These results suggest that sertraline plays an analgesic role in formalin-induced nociception probably through a serotonergic mechanism.
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Affiliation(s)
- C H Santuzzi
- Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Victória, ES, Brasil.
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10
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Borgo MV, Lopes AB, Gouvêa SA, Romero WG, Moyses MR, Bissoli NS, Abreu GR. Effect of tamoxifen on the coronary vascular reactivity of spontaneously hypertensive female rats. Braz J Med Biol Res 2011; 44:786-92. [PMID: 21845338 DOI: 10.1590/s0100-879x2011007500099] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 07/13/2011] [Indexed: 11/22/2022] Open
Abstract
Tamoxifen has been associated with a reduction in the incidence of myocardial infarction. However, the effects of tamoxifen on coronary reactivity have not been fully elucidated. The objective of this study was to determine the effects of chronic treatment with tamoxifen on coronary vascular reactivity in spontaneously hypertensive rats (SHR). Female SHR were divided into four groups (N = 7 each): sham-operated (SHAM), sham-operated and treated with tamoxifen (10 mg/kg) by gavage for 90 days (TAMOX), ovariectomized (OVX), and ovariectomized and treated with tamoxifen (OVX+TAMOX). Mean arterial pressure (MAP), heart rate (HR), coronary perfusion pressure (CPP), and coronary vascular reactivity were measured. MAP and HR were reduced (9.42 and 11.67%, respectively) in the OVX+TAMOX group compared to the OVX group (P < 0.01). The coronary vascular reactivity of the OVX+TAMOX group presented smaller vasoconstrictor responses to acetylcholine (2-64 µg) when compared to the OVX group (P < 0.01) and this response was similar to that of the SHAM group. The adenosine-induced vasodilator response was greater in the TAMOX group compared to the SHAM and OVX groups (P < 0.05). Baseline CPP was higher in OVX+TAMOX and TAMOX groups (136 ± 3.6 and 130 ± 1.5 mmHg) than in OVX and SHAM groups (96 ± 2 and 119 ± 2.3 mmHg; P < 0.01). Tamoxifen, when combined with OVX, attenuated the vasoconstriction induced by acetylcholine and increased the adenosine-induced vasodilatory response, as well as reducing the MAP, suggesting beneficial effects of tamoxifen therapy on coronary vascular reactivity after menopause.
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Affiliation(s)
- M V Borgo
- Departamento de Ciências Fisiológicas, Centro Biomédico, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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11
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Santos RL, Marin EB, Gonçalves WLS, Bissoli NS, Abreu GR, Moysés MR. Sex differences in the coronary vasodilation induced by 17 β-oestradiol in the isolated perfused heart from spontaneously hypertensive rats. Acta Physiol (Oxf) 2010; 200:203-10. [PMID: 20426771 DOI: 10.1111/j.1748-1716.2010.02140.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
AIM The relaxation induced by oestrogen in the coronary vascular bed from normotensive rats has been well described. However, almost nothing is known about this action in spontaneously hypertensive rats (SHR). We investigated the effect of 17 β-oestradiol (E(2) ) in coronary arteries from SHR as well as the contribution of the endothelium and the vascular smooth muscle to this action. METHODS Coronary arteries from male and female rats were used. Mean arterial pressure (MAP) and baseline coronary perfusion pressure (CPP) were determined. The effects of 10 μm E(2) were assessed by in bolus administration before and after endothelium denudation (0.25 μm sodium deoxycholate) or perfusion with 100 μm N(ω)-nitro-L-arginine methyl ester (L-NAME), 2.8 μm indomethacin, 0.75 μm clotrimazole, 100 μm L-NAME after endothelium denudation (0.25 μm sodium deoxycholate), 100 μm L-NAME plus 2.8 μm indomethacin, 0.75 μm clotrimazole plus 2.8 μm indomethacin and 4 mm tetraethylammonium (TEA). RESULTS MAP was higher in the male group, while CPP was higher in the female group (P<0.05). There were no differences in E(2)-induced relaxation between females and males (-17±1.6 vs. -17±2% respectively). Only in the female group the E(2) response was significantly attenuated after endothelium removal or perfusion with clotrimazole. The response to E(2) was reduced in both groups with L-NAME, L-NAME plus indomethacin, L-NAME after endothelium removal or TEA. CONCLUSIONS Nitric oxide, endothelium-derived hyperpolarizing factor and potassium channels may have the most important role to E(2) response in the female group, whereas nitric oxide and potassium channels may have the most important role in the male group.
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MESH Headings
- Animals
- Biological Factors/metabolism
- Blood Pressure
- Coronary Vessels/drug effects
- Coronary Vessels/metabolism
- Coronary Vessels/physiopathology
- Cyclooxygenase Inhibitors/pharmacology
- Disease Models, Animal
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Enzyme Inhibitors/pharmacology
- Estradiol/metabolism
- Female
- Hypertension/metabolism
- Hypertension/physiopathology
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Nitric Oxide/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Nitric Oxide Synthase/metabolism
- Perfusion
- Potassium Channel Blockers/pharmacology
- Potassium Channels/metabolism
- Rats
- Rats, Inbred SHR
- Sex Factors
- Vasodilation/drug effects
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Affiliation(s)
- R L Santos
- Department of Physiological Sciences, Biomedical Center, Federal University of Espírito Santo, Vitória, ES, Brazil
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12
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Andrade TU, Pinto VD, Medeiros ARS, Abreu GR, Moysés MR, Sampaio KN, Bissoli NS. EFFECT OF ENALAPRIL TREATMENT ON THE SENSITIVITY OF CARDIOPULMONARY REFLEXES IN RATS WITH MYOCARDIAL INFARCTION. Clin Exp Pharmacol Physiol 2007; 34:606-11. [PMID: 17581216 DOI: 10.1111/j.1440-1681.2007.04613.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
1. The aim of the present study was to evaluate the effect of treatment with enalapril on the sensitivity of cardiopulmonary reflexes 30 days after myocardial infarction in Wistar rats. 2. Animals were divided into four groups: (i) sham operated, receiving vehicle (SHAM); (ii) infarcted, receiving vehicle (0.9% NaCl; INF); (iii) sham operated, receiving enalapril (SHAME); and (iv) infarcted, receiving enalapril (INFE). 3. Enalapril was administered at a dose of 10 mg/kg per day. Serotonin (4-32 microg/kg, i.v.) was administered in order to activate the Bezold-Jarisch reflex, which was estimated as the percentage of reduction in heart rate. 4. The volume-sensitive cardiopulmonary reflex was induced by saline overload and evaluated as the percentage increase in sodium and volume renal excretion. At the end of the experiments, rats were killed and hearts excised to estimate the size of the infarction. The weight of the kidneys, lungs, liver and cardiac chambers as ratios of bodyweight was used to estimate the extent of hypertrophy. 5. The results showed an impairment in the sensitivity of the cardiopulmonary reflexes in the INF group compared with the SHAM and SHAME groups. We observed right ventricle and pulmonary hypertrophy, a reduction in mean and systolic arterial pressure and an increase in heart rate in INF animals. In the INFE group, nearly all the parameters were normal compared with the INF group, except for systolic arterial pressure, which was only partially improved. 6. The main finding of the present study was that treatment with enalapril normalized the sensitivity of the cardiopulmonary reflexes, which could be due, in part, to the reduction of cardiac hypertrophy. The present study provides information about the beneficial effects of the angiotensin-converting enzyme inhibitors by normalizing the cardiopulmonary reflexes involved with the regulation of volume and sodium, as well as control of arterial pressure and heart rate in infarcted animals.
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Affiliation(s)
- T U Andrade
- Department of Pharmacy, University Centre of Vila Velha, Vila Velha, Brazil
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13
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Rodrigues AN, Moyses MR, Bissoli NS, Pires JGP, Abreu GR. Cardiovascular risk factors in a population of Brazilian schoolchildren. Braz J Med Biol Res 2006; 39:1637-42. [PMID: 17160273 DOI: 10.1590/s0100-879x2006001200015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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: 01/17/2006] [Accepted: 08/23/2006] [Indexed: 11/22/2022] Open
Abstract
Epidemiological and clinical evidence suggests that a judicious diet, regular physical activity and blood pressure (BP) monitoring must start in early childhood to minimize the impact of modifiable cardiovascular risk factors. This study was designed to evaluate BP and metabolic parameters of schoolchildren from Vitória, Espírito Santo State, Brazil, and correlate them with cardiovascular risk factors. The study was conducted on 380 students aged 10-14 years (177 boys, 203 girls) enrolled in public schools. Baseline measurements included body mass index, BP and heart rate. The students were submitted to exercise spirometry on a treadmill. VO2max was obtained from exercise testing to voluntary exhaustion. Fasting serum total cholesterol (TC), LDL-C, HDL-C, triglycerides (TG), and glucose were measured. Nine point nine percent of the boys and 11.7% of the girls were hypertensive or had pre-hypertensive levels. There was no significant correlation between VO2max and TC, LDL-C, or TG in prepubertal children, but a slight negative correlation was detected in post-pubertal boys for HDL-C and TG. In addition, children with hypertension (3.4%) or pre-hypertensive levels (6.6%) also had comorbidity for overweight and blood lipid abnormalities (14% for triglycerides, 44.7% for TC, 25.9% for LDL-C, 52% for low HDL-C). The present study shows for the first time high correlations between prehypertensive blood pressure levels and the cardiovascular risk factors high TC, high LDL-C, low HDL-C in schoolchildren. These are important for the formulation of public health policies and strategies.
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Affiliation(s)
- A N Rodrigues
- Departamento de Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, 29042-755 Vitória, ES, Brasil
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14
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Abstract
The present study was designed to determine relaxation in response to 17 beta-estradiol by isolated perfused hearts from intact normotensive male and female rats as well as the contribution of endothelium and its relaxing factors to this action. Baseline coronary perfusion pressure was determined and the vasoactive effects of 17 beta-estradiol (10 microM) were assessed by in bolus administration before and after endothelium denudation by infusion of 0.25 microM sodium deoxycholate or perfusion with 100 microM L-NAME, 2.8 microM indomethacin, 0.75 microM clotrimazole, 100 microM L-NAME plus 2.8 microM indomethacin, and 100 microM L-NAME plus 0.75 microM clotrimazole. Baseline coronary perfusion pressure differed significantly between males (84 +/- 2 mmHg, N = 61) and females (102 +/- 2 mmHg, N = 61). Bolus injection of 10 microM 17 beta-estradiol elicited a transient relaxing response in all groups, which was greater in coronary beds from females. For both sexes, the relaxing response to 17 beta-estradiol was at least in part endothelium-dependent. In the presence of the nitric oxide synthase inhibitor L-NAME, the relaxing response to 17 beta-estradiol was reduced only in females. Nevertheless, in the presence of indomethacin, a cyclooxygenase inhibitor, or clotrimazole, a cytochrome P450 inhibitor, the 17 beta-estradiol response was significantly reduced in both groups. In addition, combined treatment with L-NAME plus indomethacin or L-NAME plus clotrimazole also reduced the 17 beta-estradiol response in both groups. These results indicate the importance of prostacyclin and endothelium-derived hyperpolarizing factor in the relaxing response to 17 beta-estradiol. 17 beta-estradiol-induced relaxation may play an important role in the regulation of coronary tone and this may be one of the reasons why estrogen replacement therapy reduces the risk of coronary heart disease in postmenopausal women.
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Affiliation(s)
- R L Santos
- Departamento de Ciências Fisiológicas, Centro Biomédico, Universidade Federal do Espírito Santo, Victoria, ES, Brazil
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15
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Gouvêa SA, Moysés MR, Bissoli NS, Pires JGP, Cabral AM, Abreu GR. Oral administration of L-arginine decreases blood pressure and increases renal excretion of sodium and water in renovascular hypertensive rats. Braz J Med Biol Res 2003; 36:943-9. [PMID: 12845383 DOI: 10.1590/s0100-879x2003000700017] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The two-kidney, one-clip renovascular (2K1C) hypertension model is characterized by a reduction in renal flow on the clipped artery that activates the renin-angiotensin system. Endothelium dysfunction, including diminished nitric oxide production, is also believed to play a role in the pathophysiology of this model. Some studies have shown an effect of L-arginine (L-Arg, a nitric oxide precursor) on hypertension. In the present study we determined the ability of L-Arg (7 days of treatment) to reduce blood pressure and alter renal excretions of water, Na+ and K+ in a model of 2K1C-induced hypertension. Under ether anesthesia, male Wistar rats (150-170 g) had a silver clip (0.20 mm) placed around the left renal artery to produce the 2K1C renovascular hypertension model. In the experimental group, the drinking water was replaced with an L-Arg solution (10 mg/ml; average intake of 300 mg/day) from the 7th to the 14th day after surgery. Sham-operated rats were used as controls. At the end of the treatment period, mean blood pressure was measured in conscious animals. The animals were then killed and the kidneys were removed and weighed. There was a significant reduction of mean blood pressure in the L-Arg-treated group when compared to control (129 7 vs 168 6 mmHg, N = 8-10 per group; P<0.05). Concomitantly, a significant enhancement of water and Na+ excretion was observed in the 2K1C L-Arg-treated group when compared to control (water: 13.0 0.7 vs 9.2 0.5 ml/day, P<0.01; Na+: 1.1 0.05 vs 0.8 0.05 mEq/day, respectively, P<0.01). These results show that orally administered L-Arg acts on the kidney, possibly inducing changes in renal hemodynamics or tubular transport due to an increase in nitric oxide formation.
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Affiliation(s)
- S A Gouvêa
- Departamento de Ciências Fisiológicas, Centro Biomédico, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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16
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Uggere TA, Abreu GR, Sampaio KN, Cabral AM, Bissoli NS. The cardiopulmonary reflexes of spontaneously hypertensive rats are normalized after regression of left ventricular hypertrophy and hypertension. Braz J Med Biol Res 2000; 33:589-94. [PMID: 10775891 DOI: 10.1590/s0100-879x2000000500014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cardiopulmonary reflexes are activated via changes in cardiac filling pressure (volume-sensitive reflex) and chemical stimulation (chemosensitive reflex). The sensitivity of the cardiopulmonary reflexes to these stimuli is impaired in the spontaneously hypertensive rat (SHR) and other models of hypertension and is thought to be associated with cardiac hypertrophy. The present study investigated whether the sensitivity of the cardiopulmonary reflexes in SHR is restored when cardiac hypertrophy and hypertension are reduced by enalapril treatment. Untreated SHR and WKY rats were fed a normal diet. Another groups of rats were treated with enalapril (10 mg kg-1 day-1, mixed in the diet; SHRE or WKYE) for one month. After treatment, the volume-sensitive reflex was evaluated in each group by determining the decrease in magnitude of the efferent renal sympathetic nerve activity (RSNA) produced by acute isotonic saline volume expansion. Chemoreflex sensitivity was evaluated by examining the bradycardia response elicited by phenyldiguanide administration. Cardiac hypertrophy was determined from the left ventricular/body weight (LV/BW) ratio. Volume expansion produced an attenuated renal sympathoinhibitory response in SHR as compared to WKY rats. As compared to the levels observed in normotensive WKY rats, however, enalapril treatment restored the volume expansion-induced decrease in RSNA in SHRE. SHR with established hypertension had a higher LV/BW ratio (45%) as compared to normotensive WKY rats. With enalapril treatment, the LV/BW ratio was reduced to 19% in SHRE. Finally, the reflex-induced bradycardia response produced by phenyldiguanide was significantly attenuated in SHR compared to WKY rats. Unlike the effects on the volume reflex, the sensitivity of the cardiac chemosensitive reflex to phenyldiguanide was not restored by enalapril treatment in SHRE. Taken together, these results indicate that the impairment of the volume-sensitive, but not the chemosensitive, reflex can be restored by treatment of SHR with enalapril. It is possible that by augmenting the gain of the volume-sensitive reflex control of RSNA, enalapril contributed to the reversal of cardiac hypertrophy and normalization of arterial blood pressure in SHR.
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Affiliation(s)
- T A Uggere
- Departamento de Ciências Fisiológicas, Centro Biomédico, Universidade Federal do Espírito Santo, Vitoria, ES, Brasil
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17
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Abstract
In spontaneously hypertensive rats, ouabain exerts an excitatory effect on baroreceptor nerve activity (BNA). The aim of this study was to determine the effects of ouabain on BNA in other experimental models of hypertension and its interaction with nitric oxide. Rats were made hypertensive using the procedures for N(omega)-nitro-L-arginine methyl ester (L-NAME), deoxycorticosterone acetate (DOCA) salt, and 2-kidney, 1 clip (2K1C) hypertension models. In these groups, systolic arterial pressure was 195+/-7, 149+/-6, and 148+/-4 mm Hg, respectively, compared with 110+/-4 mm Hg in normotensive rats. Acute ouabain administration had an excitatory effect on BNA in normotensive rats (37+/-4%), an inhibitory effect in L-NAME hypertensive rats (-60+/-7%), and no effect in DOCA-salt and 2K1C hypertensive rats. The effects of ouabain were not related to arterial pressure levels, and no excitatory effect on BNA was observed in prehypertensive DOCA-salt rats. Long-term administration of L-arginine (3 g x kg(-1) x day(-1)) prevented DOCA-salt (121+/-8 mm Hg) and 2K1C (104+/-4 mm Hg) hypertension, markedly attenuated L-NAME (130+/-9 mm Hg) hypertension, and restored the excitatory effect of ouabain on BNA in these groups to levels similar to the normotensive rats and their respective control groups. We conclude that ouabain has a diverse effect on BNA in experimental models of hypertension, and it can be normalized by L-arginine. The data also indicate that nitric oxide may play a pivotal role in mediating the excitatory effect of ouabain on BNA, and we speculate that a therapeutic combination of ouabain and L-arginine may be beneficial in secondary hypertension.
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Affiliation(s)
- G R Abreu
- Physiological Sciences Graduate Program, Biomedical Center, Federal University of Espirito Santo, Vitoria, ES, Brazil
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18
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Abreu GR, Futuro Neto HA, Cabral AM, Vasquez EC. Ouabain produces diverse excitatory effects on afferent baroreceptor nerve activity in SHR and WKY animals. Clin Exp Hypertens 1998; 20:85-94. [PMID: 9507790 DOI: 10.3109/10641969809053208] [Citation(s) in RCA: 10] [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] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effect of acute ouabain treatment was evaluated on afferent baroreceptor nerve activity in spontaneously hypertensive rats (SHR) compared with Wistar Kyoto rats (WKY). Under urethane anesthesia (1.2 mg/Kg) the discharge of the recurrent laryngeal nerve was utilized as index of arterial baroreceptor activity (BNA) in rats with the ipslateral vagus cut at a proximal level. The ouabain (30 micrograms, i.v.) treatment produced an excitatory effect on BNA without changes in basal arterial pressure in both groups studied. This effect was larger in SHR (92 +/- 10%) than WKY (37 +/- 4%, P < 0.01). The arterial pressor response to phenylephrine was similar in both SHR and WKY before (20 +/- 1 and 22 +/- 1.2 mmHg) and after (18 +/- 1.4 and 20 +/- 2 mmHg, respectively) ouabain. The BNA under phenylephrine-induced peaks of high arterial pressure was significantly higher in SHR (61 +/- 15%) than in WKY (41 +/- 5% P < 0.01) but after ouabain treatment the opposite was observed (31 +/- 5 vs. 61 +/- 4% P < 0.01). The inhibitory effects of sodium nitroprusside on arterial pressure and BNA were similar in SHR and WKY groups both before and after the ouabain treatment. These data indicate an excitatory effect of ouabain on baroreceptor nerve activity in normotensive and markedly in hypertensive rats which could contribute to the reflex arterial pressure regulation, besides the known inotropic action on the heart.
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Affiliation(s)
- G R Abreu
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, Brazil
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