Biomedical subjects

E D Moreira

Publications and source records attributed to E D Moreira.

At least 19 recordsLinked to original sources

PubMed2006

Influence of cardiopulmonary reflex on the sympathetic activity during myocardial infarction.

The time-course of changes in renal sympathetic nerve activity (RSNA), arterial and cardiopulmonary baroreflexes sensitivities was evaluated in conscious rats eight hours (8 h) and ten days (10 day) after myocardial infarction (MI), induced by coronary artery ligation. RSNA was recorded by a platinum electrode implanted in left renal nerve. Arterial and cardiopulmonary baroreflexes sensitivities were evaluated by changes in blood pressure and serotonin administration, respectively. Both 8 h and 10 day groups presented hypotension (103+/-4 vs. 102+/-2 vs. 115+/-4 mm Hg), but only 8 h showed tachycardia (422+/-22 vs. 378+/-11 vs. 384+/-9 bpm) when compared to Control rats. RSNA was depressed 8 h after MI and increased in 10 day group (12+/-2 vs. 39+/-8 vs. 22+/-2 mV/cycle). Although arterial baroreflex control of heart rate was similar in all groups, the arterial baroreflex control of RSNA in 8 h group was impaired during reductions (-0.35+/-0.10 vs. -1.66+/-0.23 vs. -0.09+/-0.14 mV/cycle/mm Hg) or increases (-0.77+/-0.17 vs. -1.63+/-0.58 vs. -1.66+/-0.17 mV/cycle/mm Hg) in blood pressure when compared to Control animals. Moreover, cardiopulmonary baroreflex bradycardic response was increased in 8 h rats and normalized in 10 day group. The results suggest that the increased cardiopulmonary baroreflex sensitivity in 8 h may contribute to the reduction in the tonic level of RSNA as well as in the impairment of the baroreflex control of RSNA in the presence of hypotension.

Animals↗

PubMed2006

Antimicrobial resistance of Escherichia coli strains causing community-acquired urinary tract infections among insured and uninsured populations in a large urban center.

We assessed the susceptibility of Escherichia coli strains causing communityacquired urinary tract infection (UTI) in a large urban center in Brazil, comparing two different populations (patients with health insurance vs. uninsured). 581 nonduplicate strains of E. coli were isolated. The prevalence of antimicrobial resistance was greater than 20% for ampicillin (51%), trimethoprim-sulfamethoxazole (43%), tetracycline (41%) and chloramphenicol (22%). Overall, 12% of the E. coli isolates were resistant to ciprofloxacin. Resistance prevalences to most antimicrobials were similar in the two study populations. Our data provide much needed information on the prevalence of antimicrobial resistance among E. coli causing communityacquired UTI in Brazil. Antimicrobial resistance among strains of E. coli causing community-acquired UTIs was relatively high, particularly resistance to ciprofloxacin.

Adolescent↗

PubMed2005

Help-seeking behaviour for sexual problems: the global study of sexual attitudes and behaviors.

The Global Study of Sexual Attitudes and Behaviors (GSSAB) investigated various aspects of sex and relationships among 27,500 men and women aged 40-80 years. Here, we report help-seeking behaviours for sexual problems in this population. A questionnaire was administered using the accepted survey method in each country. Although almost half of all sexually active respondents had experienced at least one sexual problem, less than 19% of them (18.0% of men and 18.8% of women) had attempted to seek medical help for their problem(s). The most frequent action taken by men and women was to talk to their partner (39%). Only 9% of men and women had been asked about their sexual health by a doctor in a routine visit during the past 3 years. Although sexual problems are highly prevalent, few men and women seek medical help for these problems. Overall, men and women show similar help-seeking behaviours.

Adult↗

PubMed2004

Exercise training changes autonomic cardiovascular balance in mice.

Experiments were performed to investigate the influence of exercise training on cardiovascular function in mice. Heart rate, arterial pressure, baroreflex sensitivity, and autonomic control of heart rate were measured in conscious, unrestrained male C57/6J sedentary (n = 8) and trained mice (n = 8). The exercise training protocol used a treadmill (1 h/day; 5 days/wk for 4 wk). Baroreflex sensitivity was evaluated by the tachycardic and bradycardic responses induced by sodium nitroprusside and phenylephrine, respectively. Autonomic control of heart rate and intrinsic heart rate were determined by use of methylatropine and propranolol. Resting bradycardia was observed in trained mice compared with sedentary animals [485 +/- 9 vs. 612 +/- 5 beats/min (bpm)], whereas mean arterial pressure was not different between the groups (106 +/- 2 vs. 108 +/- 3 mmHg). Baroreflex-mediated tachycardia was significantly enhanced in the trained group (6.97 +/- 0.97 vs. 1.6 +/- 0.21 bpm/mmHg, trained vs. sedentary), whereas baroreflex-mediated bradycardia was not altered by training. The tachycardia induced by methylatropine was significantly increased in trained animals (139 +/- 12 vs. 40 +/- 9 bpm, trained vs. sedentary), whereas the propranolol effect was significantly reduced in the trained group (49 +/- 11 vs. 97 +/- 11 bpm, trained vs. sedentary). Intrinsic heart rate was similar between groups. In conclusion, dynamic exercise training in mice induced a resting bradycardia and an improvement in baroreflex-mediated tachycardia. These changes are likely related to an increased vagal and decreased sympathetic tone, similar to the exercise response observed in humans.

Animals↗

PubMed2004

Risk factors for Helicobacter pylori infection in children: is education a main determinant?

To investigate potential risk factors associated with Helicobacter pylori (Hp) infection, we performed a case-control study in 167 consecutively selected hospitalized children in Salvador, Brazil. Hp infection was identified by the presence of IgG against Hp in serum samples. Data were gathered using a structured questionnaire, 38.3% children were found to be seropositive and classified as cases, and 61.7% were seronegative controls. After multivariate analysis, independent variables associated with Hp infection included: the educational attainment of the child's provider > or = 11 years (OR 0.1, 95% CI 0.01-0.9), poor garbage disposal service (OR 2.2, 95% CI 1.0-4.9), thumb sucking (OR 4.6, 95% CI 1.1-19.8), brushing teeth more than once a day (OR 5.6, 95% CI 1.8-17.7), having a pet dog (OR 2.5, 95% CI 1.0-6.1), and a history of chronic urticaria (OR 4.0, 95% CI 1.5-10.8). The risk factors identified are consistent with some, but not all, previous studies supporting either oral-oral or faecal-oral transmission of Hp. Our data suggested that a higher educational attainment might play an important role in preventing Hp infection.

Case-Control Studies↗

PubMed2004

Prevalence of sexual dysfunctions and correlated conditions in a sample of Brazilian women--results of the Brazilian study on sexual behavior (BSSB).

The objective of this study was to assess the prevalence and risk factors of female sexual dysfunctions across a selection of social groups. In all, 1219 women in the community, aged 18 y or older, answered a 38-question self-applicable questionnaire. Statistical analysis was performed using multivariate logistic regression. The average age was 35.6 y (s.d.=12.31) and the average number of sexual intercourses was 2.8 (s.d.=1.94) a week. At least one sexual dysfunction was reported by 49% of the women; lack of sexual desire (LSD) by 26.7%; pain during sexual intercourse (PSI) by 23.1% and orgasmic dysfunction (OD) by 21%. Women aged over 40 y represented an LSD and OD risk factor, whereas women aged over 25 y showed less likelihood of presenting PSI. The educational level was inversely correlated with the risk of LSD, OD and PSI. Depression and cardiopathies increased PSI occurrences and women with diabetes mellitus showed a higher probability of developing LSD and OD. In conclusion, almost half the women had at least one sexual dysfunction, and prevalence increased with age and lower educational levels. Preventive medical care for the female population, mainly for patients with chronic and/or degenerative diseases, considerably reduced the chances of sexual dysfunction.

Adult↗

PubMed2003

Prevalence of erectile dysfunction and associated factors among men without concomitant diseases: a population study.

We interviewed a population sample of 2412 men aged 40-70 y in Brazil, Italy, Japan and Malaysia about medical history, lifestyle habits and sexual behavior. Men were classified as having moderate or complete erectile dysfunction (ED) if they reported to be sometimes or never able to achieve and maintain an erection satisfactory for sexual intercourse, respectively. There were 1335 men with no diagnosis of cardiovascular or prostate diseases, diabetes, ulcer or depression, nor taking hormones. The prevalence of ED was 16.1%. ED was associated with age (the risk increased 8% per y), moderate (odds ratio (OR)=2.2) or severe (OR=4.9) lower urinary tract symptoms and smoking (OR=2.3 for >30 cigarettes/day). It was inversely associated with physical activity (OR=0.5) and higher educational levels. Between the ages of 40 and 70 y, almost one in six 'healthy' men is affected by ED. Further research should look at preclinical disease stages and genetic factors.

Adult↗

PubMed2002

Prevalence and correlates of erectile dysfunction in Salvador, northeastern Brazil: a population-based study.

Our objectives were to determine the prevalence of erectile dysfunction (ED) in Brazil and to explore potential sociodemographic, medical, and lifestyle correlates. A cross-sectional, population-based, household survey was conducted in Salvador, Bahia, Brazil. Cluster samples of representative households were randomly selected for interviews. Of 654 eligible subjects, 602 (92%) participated. A structured questionnaire was administered by trained interviewers. ED was categorized as 'none', 'mild', 'moderate', or 'severe' according to the ability to 'attain and/or maintain an erection satisfactory for sexual intercourse'. All data were obtained by self-report. The age-adjusted prevalence of ED was 39.5% (minimal 25.1%, moderate 13.1%, severe 1.3%). Prevalence and severity increased with age. Having never been married, diabetes, depression, or prostate disease and current depressive or lower urinary tract symptoms were significantly (P<0.05) associated with increased prevalence. Medical, sociodemographic, and lifestyle variables associated with ED may alert physicians to patients at risk for ED and offer insight to its etiology.

Adult↗

PubMed2002

The epidemiology of erectile dysfunction and its correlates in men with chronic renal failure on hemodialysis in Londrina, southern Brazil.

Erectile dysfunction (ED) is a common condition in aging men, but little is known about the prevalence of ED in some specific groups of patients such as those with end-stage renal disease (ESRD). A cross-sectional study was conducted to determine the prevalence of ED in ESRD patients undergoing hemodialysis in two clinics of Londrina, Brazil. The prevalence and severity of ED were assessed using the International Index of Erectile Function and a single global question. The dependence of ED on independent variables was evaluated by logistic regression. Some degree of ED was found in 86.4% of our sample (n=118). Complete ED was reported by 25.4% of subjects, moderate ED by 35.4%, and minimal ED by 24.6%. Subjects < 50 y old had a prevalence of moderate/complete ED of 52.6%, whereas in men > or = 50 y old, it was 70.5%. Age, diabetes, and low income were significantly associated with ED. Although highly prevalent, only a low percentage of uremic ESRD patients on hemodialysis were being treated for ED. Our data suggest that ED is related to uremia and other comorbid conditions that often accompany ESRD.

Adult↗

PubMed2001

Prevalence and correlates of erectile dysfunction: results of the Brazilian study of sexual behavior.

OBJECTIVES: To determine the prevalence of erectile dysfunction (ED) and explore its potential sociodemographic, medical, and lifestyle correlates. METHODS: While attending the "Health Awareness Fair" in nine major cities in Brazil, 1286 men completed a questionnaire regarding ED, demographic data, and medical conditions. ED was assessed by a single global self-rating question, in which subjects were asked to describe themselves as able to achieve and maintain an erection good enough for sexual intercourse always, usually, sometimes, or never, and the responses were used to classify the subjects as having no, minimal, moderate, or complete ED, respectively. Age-adjusted bivariate and multivariate analyses were carried out to calculate the prevalence odds ratios and 95% confidence intervals for the potential covariates. RESULTS: Overall, 46.2% of men reported some degree of ED (minimal 31.5%, moderate 12.1%, complete 2.6%). The prevalence of complete ED increased 10 times from 1% to 11% between subjects younger than 40 and older than 70 years; moderate ED rose from 8% to 27%, and minimal ED remained constant at approximately 31%. In bivariate age-adjusted analyses, low educational attainment, black race/ethnicity, homo/bisexuality, and a history of diabetes, hypertension, or depression were significantly (P <0.05) associated with an increased prevalence of ED. In the multivariate logistic regression model, these variables remained significantly associated with ED. CONCLUSIONS: The results of our study show that ED is a major health problem in Brazil and both the severity and prevalence increase with age. The medical, sociodemographic, and lifestyle variables associated with ED may alert physicians to patients who are at risk of ED, as well as offer clues to the etiology of ED.

Adult↗

PubMed2001

Baroreflex depression persists in the early phase after hypertension reversal.

The baroreflex control of heart rate (HR) was evaluated in conscious chronic renal hypertensive rats (RHR; 1K-1C, 2 mo) under control conditions and after reversal of hypertension by unclipping the renal artery or sodium nitroprusside infusion. Unclipping and nitroprusside infusion were both followed by significant decreases in the mean arterial pressure (unclipping: from 199 +/- 4 to 153 +/- 8 mmHg; nitroprusside infusion: from 197 +/- 9 to 166 +/- 6 mmHg) as well as slight and significant increases, respectively, in the baroreflex bradycardic response index (unclipping: from 0.2 +/- 0.04 to 0.6 +/- 0.1 beats x min(-1) x mmHg(-1); nitroprusside infusion: from 0.1 +/- 0.04 to 0.5 +/- 0.1 beats x min(-1) x mmHg(-1)). However, this index was still depressed compared with that for normotensive control rats (2.1 +/- 0.2 beats x min(-1) x mmHg(-1)). The index for the baroreflex tachycardic response was also depressed under control conditions and remained unchanged after hypertension reversal. RHR possessed markedly attenuated vagal tone as demonstrated by pharmacological blockade of parasympathetic and sympathetic control of HR with methylatropine and propranolol, respectively. A reduced bradycardic response was also observed in anesthetized RHR during electrical stimulation of the vagus nerve or methacholine chloride injection, indicating impairment of efferent vagal influence over the HR. Together, these data indicate that 2 h after hypertension reversal in RHR, the previously described normalization of baroreceptor gain occurs independent of the minimal or lack of recovery of baroreflex control over HR.

Animals↗

PubMed2001

Chronic AT(1) receptor blockade alters autonomic balance and sympathetic responses in hypertension.

In the coarctation hypertension model, we have shown that chronic treatment with losartan causes both normalization of impaired reflex control of heart rate and partial correction of the depressed aortic nerve activity/pressure relationship, even with the persistence of hypertension. In the present study, we analyzed the effects of angiotensin II blockade on the efferent pathways of coarcted and sham-operated groups treated chronically with vehicle or losartan (10 mg/kg per day PO). Hypertension was induced by subdiaphragmatic aortic coarctation, and the treatments lasted 9 days (4 control and 5 experimental days). On day 5, autoregressive power spectral analysis was performed on heart rate recordings made in conscious rats. Other groups were used for sympathetic splanchnic nerve activity recordings made simultaneously with pressure (anesthetized rats) at basal condition and during loading/unloading of baroreceptors. Losartan treatment induced a significant reduction in basal pressure but did not interfere with the development of hypertension (similar pressure increases of 24% and 28% over control values in losartan and vehicle groups, respectively). In vehicle-treated rats, establishment of hypertension was accompanied by a marked change in power spectral density from high- (1.19+/-0.06 Hz, 33+/-6%) to low-frequency components (0,42+/-0.03 Hz, 54+/-6%), with increased low-frequency-to-high-frequency ratio. When compared with sham-operated vehicle-treated rats, there was also increase in the gain of sympathetic activity/pressure relationship, with displacement of lower plateau toward high levels of sympathetic activity. No changes in the power spectral density and sympathetic activity/pressure relationship were observed when hypertension developed in the presence of chronic angiotensin type 1 (AT(1)) receptor blockade. The data suggest that angiotensin II, activated during the establishment of coarctation hypertension, acts via AT(1) receptors to alter sympathovagal balance, facilitating the sympathetic outflow to heart and peripheral circulation during baroreceptors unloading. Data also indicate that the observed effects are not conditioned by preexisting pressure levels.

Angiotensin Receptor Antagonists↗

PubMed2001

Reporting on methods of subgroup analysis in clinical trials: a survey of four scientific journals.

Results of subgroup analysis (SA) reported in randomized clinical trials (RCT) cannot be adequately interpreted without information about the methods used in the study design and the data analysis. Our aim was to show how often inaccurate or incomplete reports occur. First, we selected eight methodological aspects of SA on the basis of their importance to a reader in determining the confidence that should be placed in the author's conclusions regarding such analysis. Then, we reviewed the current practice of reporting these methodological aspects of SA in clinical trials in four leading journals, i.e., the New England Journal of Medicine, the Journal of the American Medical Association, the Lancet, and the American Journal of Public Health. Eight consecutive reports from each journal published after July 1, 1998 were included. Of the 32 trials surveyed, 17 (53%) had at least one SA. Overall, the proportion of RCT reporting a particular methodological aspect ranged from 23 to 94%. Information on whether the SA preceded/followed the analysis was reported in only 7 (41%) of the studies. Of the total possible number of items to be reported, NEJM, JAMA, Lancet and AJPH clearly mentioned 59, 67, 58 and 72%, respectively. We conclude that current reporting of SA in RCT is incomplete and inaccurate. The results of such SA may have harmful effects on treatment recommendations if accepted without judicious scrutiny. We recommend that editors improve the reporting of SA in RCT by giving authors a list of the important items to be reported.

Data Interpretation, Statistical↗

PubMed2000

Aging and baroreflex control of RSNA and heart rate in rats.

Aging is associated with altered autonomic control of cardiovascular function, but baroreflex function in animal models of aging remains controversial. In this study, pressor and depressor agent-induced reflex bradycardia and tachycardia were attenuated in conscious old (24 mo) rats [57 and 59% of responses in young (10 wk) Wistar rats, respectively]. The intrinsic heart rate (HR, 339 +/- 5 vs. 410 +/- 10 beats/min) was reduced in aged animals, but no intergroup differences in resting mean arterial blood pressure (MAP, 112 +/- 3 vs. 113 +/- 5 mmHg) or HR (344 +/- 9 vs. 347 +/- 9 beats/min) existed between old and young rats, respectively. The aged group also exhibited a depressed (49%) parasympathetic contribution to the resting HR value (vagal effect) but preserved sympathetic function after intravenous methylatropine and propranolol. An implantable electrode revealed tonic renal sympathetic nerve activity (RSNA) was similar between groups. However, old rats showed impaired baroreflex control of HR and RSNA after intravenous nitroprusside (-0.63 +/- 0. 18 vs. -1.84 +/- 0.4 bars x cycle(-1) x mmHg(-1) x s(-1)). Therefore, aging in rats is associated with 1) preserved baseline MAP, HR, and RSNA, 2) impaired baroreflex control of HR and RSNA, and 3) altered autonomic control of resting HR.

Aging↗

PubMed2000

Exercise training increases baroreceptor gain sensitivity in normal and hypertensive rats.

Exercise training attenuates arterial hypertension and increases baroreflex sensitivity in spontaneous hypertension. However, no information exists regarding the portion of the baroreflex arch in which this attenuation takes place. We tested the hypothesis that exercise training increases the afferent pathway sensitivity of baroreflex control in both normotensive and spontaneously hypertensive rats (SHR). Arterial pressure and whole-nerve activity of the aortic baroreceptor (multifiber preparation) were evaluated in 30 male rats assigned to 4 groups: sedentary and exercise-trained normotensive rats and sedentary and exercise-trained SHR. Exercise training was performed on a motor treadmill, 5 d/wk for 60 minutes, gradually progressing toward a speed of 26.8 m/min. Exercise training reduced mean arterial pressure in conscious exercise-trained SHR (183+/-4 versus 165+/-7 mm Hg). The relation between changes in aortic baroreceptor discharge and changes in systolic arterial pressure increased significantly in exercise-trained normotensive rats (2.09+/-0.1 versus 1.44+/-0.1%/mm Hg) and exercise-trained SHR (0.92+/-0.1 versus 0.71+/-0.1%/mm Hg) compared with their respective sedentary rats. Likewise, the average aortic baroreceptor gain sensitivity (calculated by logistic equation) was significantly higher in exercise-trained normotensive rats (2.25+/-0.19 versus 1.77+/-0.03%/mm Hg) and exercise-trained SHR (1.07+/-0.04 versus 0.82+/-0.05%/mm Hg) compared with their respective sedentary control rats. In conclusion, exercise training increases aortic baroreceptor gain sensitivity in normotensive and SHR, thus improving baroreceptor sensitivity, which may result in a more efficient arterial pressure regulation by the baroreflexes.

Afferent Pathways↗

PubMed2000

Acute AT1 receptor blockade does not improve the depressed baroreflex in rats with chronic renal hypertension.

To assess the role of angiotensin II in the sensitivity of the baroreflex control of heart rate (HR) in normotensive rats (N = 6) and chronically hypertensive rats (1K1C, 2 months, N = 7), reflex changes of HR were evaluated before and after (15 min) the administration of a selective angiotensin II receptor antagonist (losartan, 10 mg/kg, iv). Baseline values of mean arterial pressure (MAP) were higher in hypertensive rats (195 +/- 6 mmHg) than in normotensive rats (110 +/- 2 mmHg). Losartan administration promoted a decrease in MAP only in hypertensive rats (16%), with no changes in HR. During the control period, the sensitivity of the bradycardic and tachycardic responses to acute MAP changes were depressed in hypertensive rats (approximately 70% and approximately 65%, respectively) and remained unchanged after losartan administration. Plasma renin activity was similar in the two groups. The present study demonstrates that acute blockade of AT1 receptors with losartan lowers the MAP in chronic renal hypertensive rats without reversal of baroreflex hyposensitivity, suggesting that the impairment of baroreflex control of HR is not dependent on an increased angiotensin II level.

Angiotensin II↗

PubMed1999

Cardiopulmonary reflex impairment in experimental diabetes in rats.

The aim of the present study was to evaluate the sensitivity of the cardiopulmonary receptors in experimental diabetes induced by streptozotocin by the use of 2 different methods: (1) administration of increasing doses of serotonin to analyze peak changes of arterial pressure and heart rate for each given dose in conscious intact normal and diabetic rats; (2) expanding blood volume with the use of dextran (6%) to produce similar increases in left ventricular end-diastolic pressure to quantify the arterial pressure, heart rate, and renal sympathetic nerve activity in sinoaortic, denervated, anesthetized normal and diabetic rats. Blood samples were collected to measure blood glucose. Diabetic rats showed hyperglycemia (22+/-0. 7 versus 7+/-0.2 mmol/L), reduced body weight (226+/-12 versus 260+/-4 g) and heart rate (294+/-14 versus 350+/-10 bpm), and similar arterial pressure (104+/-4 versus 113+/-4 mm Hg) when compared with control rats. Serotonin induced significant bradycardia and hypotension, which were similar and proportional to the dose injected in both groups. Mean arterial pressure and heart rate decreases in response to volume overload were significantly lower in diabetic than in control rats. The reflex reduction of the renal sympathetic nerve activity as expressed by percentage changes in nerve activity in response to increasing left end-diastolic pressure was abolished in diabetic animals (1.9+/-0.8% versus -14+/-4%/mm Hg in controls). These results showed an impairment of cardiopulmonary reflex control of circulation in diabetes during acute volume expansion. The normal responses to serotonin administration indicated that the cardiopulmonary reflex is still preserved in diabetic rats.

Animals↗

PubMed1999

Comparison of three methods for the determination of baroreflex sensitivity in conscious rats.

Baroreflex sensitivity was studied in the same group of conscious rats using vasoactive drugs (phenylephrine and sodium nitroprusside) administered by three different approaches: 1) bolus injection, 2) steady-state (blood pressure (BP) changes produced in steps), 3) ramp infusion (30 s, brief infusion). The heart rate (HR) responses were evaluated by the mean index (mean ratio of all HR changes and mean arterial pressure (MAP) changes), by linear regression and by the logistic method (maximum gain of the sigmoid curve by a logistic function). The experiments were performed on three consecutive days. Basal MAP and resting HR were similar on all days of the study. Bradycardic responses evaluated by the mean index (-1.5 +/- 0.2, -2.1 +/- 0.2 and -1.6 +/- 0.2 bpm/mmHg) and linear regression (-1.8 +/- 0.3, -1.4 +/- 0.3 and -1.7 +/- 0.2 bpm/mmHg) were similar for all three approaches used to change blood pressure. The tachycardic responses to decreases of MAP were similar when evaluated by linear regression (-3.9 +/- 0.8, -2.1 +/- 0.7 and -3.8 +/- 0.4 bpm/mmHg). However, the tachycardic mean index (-3.1 +/- 0.4, -6.6 +/- 1 and -3.6 +/- 0.5 bpm/mmHg) was higher when assessed by the steady-state method. The average gain evaluated by logistic function (-3.5 +/- 0.6, -7.6 +/- 1.3 and -3.8 +/- 0.4 bpm/mmHg) was similar to the reflex tachycardic values, but different from the bradycardic values. Since different ways to change BP may alter the afferent baroreceptor function, the MAP changes obtained during short periods of time (up to 30 s: bolus and ramp infusion) are more appropriate to prevent the acute resetting. Assessment of the baroreflex sensitivity by mean index and linear regression permits a separate analysis of gain for reflex bradycardia and reflex tachycardia. Although two values of baroreflex sensitivity cannot be evaluated by a single symmetric logistic function, this method has the advantage of better comparing the baroreflex sensitivity of animals with different basal blood pressures.

Analysis of Variance↗