A longitudinal study of pain sensitivity and blood pressure in adolescent boys: Results from a 5-year follow-up.

A growing literature has observed a significant reduction in pain sensitivity among hypertensive animals and humans. It is uncertain whether a reduced sensitivity to pain can be observed in normotensive individuals who go on to develop high blood pressure. Blood pressure (BP) was reassessed in one hundred fifteen 19-year-old boys initially tested at age 14, when they were also presented with a pain stimulus (mechanical finger pressure). Hierarchical regression analyses indicated that information regarding pain tolerance improved prediction of changes in systolic and diastolic blood pressure beyond that afforded by differences in BP at age 14, parental history of hypertension, and body mass index. These analyses suggest that pain sensitivity may be associated with physiological processes involved in the development of sustained high blood pressure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between pain sensitivity and resting arterial blood pressure in patients with painful temporomandibular disorders

OBJECTIVE: Patients experiencing temporomandibular disorders (TMD) show greater sensitivity to painful stimuli than age- and gender-matched control subjects. This enhanced pain sensitivity may result, at least in part, from an alteration in pain regulatory systems that are influenced by resting arterial blood pressure. In this study, we examined the relationship between resting systolic blood pressure and pain perception in 64 female TMD and 23 age-matched pain-free female subjects. METHOD: Resting arterial blood pressure and measures of thermal and ischemic pain threshold and tolerance were determined for each participant. Subjective ratings of thermal pain evoked by suprathreshold noxious thermal stimuli (45-49 degrees C) using a magnitude matching procedure were also obtained for both groups. RESULTS: TMD patients had lower thermal and ischemic pain thresholds and tolerances than pain-free subjects (ps < .05). Both groups provided equivalent intensity ratings to suprathreshold noxious thermal stimuli. A median split of each group based on resting systolic blood pressure revealed an influence of blood pressure on both thermal and ischemic pain perception for the Pain-Free group. The Pain-Free high resting blood pressure subgroup had higher thermal pain tolerances, higher ischemic pain thresholds, and provided lower magnitude estimates of the intensity of graded heat pulses compared with the Pain-Free low blood pressure subgroup. A trend toward a significant effect of blood pressure level on ischemic pain tolerance was also observed for the Pain-Free group. In contrast to the Pain-Free group, blood pressure level did not influence ischemic or thermal pain perception for TMD patients. Similar to the lack of effect of resting blood pressure on experimental pain perception in TMD patients, resting blood pressure was not related to measures of clinical orofacial pain in TMD patients. CONCLUSIONS: These findings confirm our previous findings that TMD patients are more sensitive to noxious stimuli and suggest that painful TMD may result, at least in part, from an impairment in central pain regulatory systems that are influenced by resting arterial blood pressure.     

Protective effect of GTS-21, a novel nicotinic receptor agonist, on delayed neuronal death induced by ischemia in gerbils

BACKGROUND: The difference between clinic and ambulatory average daytime blood pressures is frequently taken as a surrogate measure of the 'white-coat effect' (i.e. the pressor reaction triggered in the patient by the physician's visit). OBJECTIVE: To assess the reproducibility of this difference and its relationship with clinic and average ambulatory daytime blood pressure levels. DESIGN AND METHODS: These issues were addressed with two large groups of subjects in whom both clinic and ambulatory blood pressures were measured, namely 783 outpatients with systolic and diastolic essential hypertension [Group 1, aged 50.8+/-9.4 years (mean +/- SD)], participating in standardized Italian trials of antihypertensive drugs, and 506 elderly patients (group 2, age 71+/-7 years) with isolated systolic hypertension, participating in the European Syst-Eur trial. RESULTS: The clinic-daytime blood pressure difference for the essential systolic and diastolic hypertensive patients (group 1) was 13.6+/-14.3 mmHg for systolic and 9.1+/-8.6 mmHg for diastolic blood pressure (P always < 0.01). This difference for the elderly patients with isolated systolic hypertension (group 2) was 21.2+/-16.0 mmHg for systolic and only 1.3+/-10.2 mmHg for diastolic blood pressure (P < 0.01 and P < 0.05, respectively). In both studies little or no systematic clinic-daytime difference could be observed for heart rate. The reproducibility of the clinic-daytime blood pressure difference, tested for 108 essential systolic and diastolic hypertensive patients from group 1 and 128 isolated systolic hypertensives from group 2, was invariably lower than that both of daytime and of clinic blood pressure values. Finally, the clinic-daytime blood pressure difference was progressively higher for increasing levels of clinic blood pressure and progressively lower for higher levels of ambulatory daytime blood pressure. CONCLUSIONS: Thus, the clinic-daytime blood pressure difference has a limited reproducibility; depends not only on clinic but also on daytime average blood pressure, which means that its size is a function of the blood pressure criteria employed for selection of the patients in a trial; and is never associated with a systematic clinic-daytime difference in heart rate, which further questions its use as a reliable surrogate measure of the true pressor response induced in the patient by the doctor's visit.     

Domiciliary liquid oxygen versus concentrator treatment in chronic hypoxaemia: a cost-utility analysis

An elevated red blood cell (RBC) sodium-lithium countertransport (Na-Li CT) is associated with high blood pressure (BP) in cross-sectional investigations; however, its value as a predictor of future hypertension, and thus of cardiovascular risk, has not been defined. The present study evaluated the association between Na-Li CT and risk of future hypertension in a sample of 106 untreated normotensive middle-aged men participating in the Olivetti Prospective Heart Study in southern Italy. BP, anthropometric and metabolic variables, and RBC Na-Li CT were measured at baseline in 1987 and at a follow-up visit in 1994 through 1995. Na-Li CT was stable over time (r=0.85) and was significantly associated to systolic BP in both visits. Of the 106 initially normotensive participants, 14 were found to be hypertensive at the 8-year follow-up examination. Eleven of these 14 hypertensives were in the highest tertile of systolic BP at baseline, and 9 of 11 also had an elevated baseline Na-Li CT. In multiple logistic regression analysis, baseline BP, Na-Li CT, and age were all significant predictors of the risk of future hypertension. Individuals with baseline systolic BP in the highest tertile had a 60% risk of developing hypertension if their Na-Li CT was also high, whereas their risk was only 5% if Na-Li CT was in the two lowest tertiles (P=0.003). RBC Na-Li CT was a valuable predictor of subsequent hypertension in middle-aged men with a high-normal BP level for their age.     

The effect of heparin on the activity of Trichosporon cutaneum casein kinase I

To compare hypertensive end-organ damage in two genetic forms of hypertension we assessed cardiovascular function in two rat strains of genetic hypertension: transgenic rats overexpressing the mouse Ren-2 gene [(TGR(mREN2)27]) and blood pressure matched spontaneously hypertensive rats (SHR). Despite similarly elevated blood pressure, systolic dp/dt (mmHg/s) was more impaired in transgenic rats (3099 +/- 446) than in SHR (3571 +/- 272) and normals (4342 +/- 119; P < 0.05). Left ventricular weight (mg/g body weight) increased more in the transgenic rats (40 +/- 3) than in SHR (31 +/- 2) and normals (26 +/- 2). Endothelium-dependent relaxation was significantly decreased only in the transgenic rats. This study shows significantly more cardiac and endothelial dysfunction in transgenic, hypertensive TGR (mREN2)27 than in age and blood pressure matched SHR. This supports the hypothesis that chronic activation of the renin-angiotensin system significantly contributes to hypertensive end-organ damage.     

How far should blood pressure be reduced in diabetic hypertensive patients?

EPIDEMIOLOGY OF DIABETES: Diabetes mellitus and arterial hypertension are closely related diseases that strongly predispose an individual to atherosclerotic cardiovascular disease and to renal failure. High blood pressure is twice as frequent in diabetics compared with the general population, and often precedes and contributes to the development of diabetic nephropathy. The prevalence of coexisting arterial hypertension and non-insulin-dependent diabetes mellitus (NIDDM) is increasing as populations age, giving an increased prevalence of both diseases. TREATMENT OF HYPERTENSIVE DIABETIC PATIENTS: The goal of treating arterial hypertension in diabetic patients is to prevent death and disability associated with high blood pressure. In addition, other reversible risk factors for cardiovascular disease, seen so frequently in hypertensive diabetics, also need to be addressed. The optimal goal of blood pressure control in diabetics has not been established, but there are indications that it should be lower than the 130/85 mmHg systolic/diastolic pressure recommended by current guidelines. In the presence of multiple associated risk factors, most guidelines suggest a threshold for intervention of > or = 140/90 mmHg. In particular, in hypertensive diabetic patients intervention must be early and aggressive.     

Cardiovascular outcome in white-coat versus sustained mild hypertension: a 10-year follow-up study

BACKGROUND: The aim of this study was to compare the risk conferred by white-coat versus sustained mild hypertension for the development of cardiovascular disease. METHODS AND RESULTS: Patients (n=479) who underwent 24-hour intra-arterial ambulatory blood pressure monitoring on the basis of a persistently elevated clinic systolic blood pressure of 140 to 180 mm Hg were followed up for the development of subsequent cardiovascular events during a 9.1+/-4. 2-year period. White-coat hypertension, defined as a clinic systolic blood pressure of 140 to 180 mm Hg associated with a 24-hour ambulatory systolic blood pressure <140 mm Hg and diastolic blood pressure <90 mm Hg, was present in 126 patients, and the remainder had sustained mild hypertension. A subgroup of patients without complications underwent follow-up echocardiography and carotid ultrasound. White-coat hypertensives were younger (44+/-12 versus 52+/-10 years, respectively; P<0.001) and had a significantly lower incidence of cardiovascular events (1.32 versus 2.56 events per 100 patient-years, respectively; P<0.001) than sustained hypertensives. Multivariate analysis revealed age (P=0.002), sex (P=0.007), race (P=0.001), smoking (P=0.005), and the presence of white-coat hypertension (hazard ratio, 0.29; 95% CI, 0.09 to 0.90; P=0.04) to be independent predictors of subsequent cardiovascular events. Subgroup analysis in patients without complications revealed a lower incidence of left ventricular hypertrophy and lesser degrees of carotid hypertrophy in the white-coat group. CONCLUSIONS: These findings indicate a relatively benign outcome in white-coat hypertension compared with sustained mild hypertension.     

The difference between clinical ambulatory measured blood pressure and daily monitored pressure does not reflect the "white coat effect"

The difference between clinic and average daytime ambulatory blood pressure is frequently used to identify patients with "white coat" hypertension (i.e. with a pronounced pressor response to the clinical evaluation) although there is no evidence that this difference is indeed due to a white coat effect. In 28 mild hypertensive outpatients, the blood pressure was continuously recorded by a noninvasive finger device before and during the doctor's visit. The peak blood pressure increase, recorded during the visit was compared with the difference between clinic and daytime average ambulatory blood pressure. Peak increases in systolic and diastolic finger blood pressure during the doctor's visit were 38.2 +/- 3.1 mmHg and 20.7 +/- 1.6 mmHg, respectively compared to pre visit values (means +/- standard error, both p < 0.01). Daytime average systolic and diastolic blood pressure were 135.5 +/- 2.5 mmHg and 89.2 +/- 1.9 mmHg, both being lower than the corresponding clinic blood pressure values (146.6 +/- 3.6 mmHg and 94.9 +/- 2.2 mmHg, p < 0.01). Their differences, however, were < 30% of the peak finger blood pressure increase during the physician's visit. While the physician's visit was associated with tachycardia (+9.0 +/- 1.6 b/min, p < 0.01) there was no difference between clinic and daytime average heart rate. The alerting reaction and the pressor response induced by the physician's visit is not reflected by the difference between clinic and daytime average blood pressure. Such a difference is not therefore a reliable measure of the white coat effect.     

Photonuclear production in tissue for different 50 MV bremsstrahlung beams

BACKGROUND: The occurrence of lacunar infarction is closely related to arterial hypertension. However, there is only limited and partly controversial knowledge regarding the possible pathogenetic role of circadian blood pressure changes. OBJECTIVE: To evaluate the relationship between circadian blood pressure rhythm, occurrence, and extent of lacunar infarction. METHODS: We analyzed circadian blood pressure patterns, other cardiovascular risk factors, and occurrence of lacunar infarction in 118 hospitalized patients older than 55 years. Noninvasive 24-hour blood pressure measurements and magnetic resonance or computed tomographic brain imaging were performed in 61 patients with lacunar infarction and in 57 control patients. Daytime blood pressure variability was defined as the within-subject SD of all systolic and diastolic blood pressure readings during the daytime measurement period. Circadian blood pressure variation was defined as the average percentage change of nighttime blood pressure values compared with the daytime blood pressure values. RESULTS: Patients with lacunar infarction were significantly older and showed more often a history of arterial hypertension, elevated average daytime blood pressure values, an increased systolic daytime blood pressure variability, and a reduced circadian blood pressure variation due to an increased incidence of a pathologic nighttime blood pressure increase. No significant correlation was found between these parameters and the number of lacunae. A logistic regression analysis revealed that a reduced systolic circadian blood pressure variation, age, systolic average daytime blood pressure, and a history of arterial hypertension were best correlated with the occurrence of lacunar infarction. CONCLUSION: Reduced nighttime decline in systolic blood pressure may be an important risk factor for the development of lacunar infarction in addition to the absolute level of blood pressure and age.     

Nocturnal blood pressure and relation to vasoactive hormones and renal function in hypertension and chronic renal failure

The purpose of this study was to assess the blood pressure profile and to measure vasoactive hormones in patients with essential hypertension (n=61), secondary hypertension (n=32) and chronic renal failure (n=32) matched with healthy control subjects (n=35), and to study the relationship between circadian changes in blood pressure and baseline levels of vasoactive hormones and renal function. Non-invasive, automatic blood pressure measurement was performed for 24 or 48 h. Venous plasma concentrations of renin, angiotensin II, aldosterone, arginine vasopressin, atrial natriuretic peptide and endothelin were measured. The mean 24-h blood pressure was higher in all groups of hypertensive patients than in control subjects. The nocturnal blood pressure fall was preserved in essential hypertension, in contrast to secondary hypertension in which it was attenuated. In the patients with chronic renal failure the 24-h mean blood pressure was the same as in the controls. Night-time blood pressure was higher among the chronic renal failure patients than in the control group, and the nightly blood pressure fall in both diastolic and systolic blood pressure was reduced. Plasma concentrations of renin activity, arginine vasopressin, atrial natriuretic peptide, aldosterone and endothelin were significantly increased in secondary hypertension and chronic renal failure, compared to essential hypertension and control subjects. Plasma angiotensin II was increased in chronic renal failure compared to essential hypertension and controls. Estimated creatinine clearance and nightly blood pressure dips were inversely correlated in essential and secondary hypertension, i.e. with a decreasing renal function both systolic and diastolic nightly blood pressure dips were gradually attenuated. In the whole group of patients the nightly systolic and diastolic blood pressure dips were negatively correlated to basal plasma renin activity, plasma aldosterone and atrial natriuretic peptide levels, i.e. the higher the basal plasma hormone level the lower the blood pressure dip. In conclusion, patients with essential hypertension have elevated but normally configured 24-h blood pressure profiles, and patients with different kinds of secondary hypertension have elevated 24-h blood pressure profiles and attenuated nightly systolic and diastolic blood pressure falls. The more the renal function is reduced and the more the plasma levels of renin and aldosterone are increased, the more the nocturnal fall in blood pressure is reduced. It is suggested that the attenuated or absent decrease in nocturnal blood pressure in secondary renal hypertension is caused by an abnormally increased secretion of vasoactive hormones and/or by so far unknown factors released from the diseased kidney.     

Correlation of SPECT and PET cardiac images by a surface matching registration technique

To study the potential role of sympathetic activity in the pathogenesis of arterial hypertension associated with autosomal dominant polycystic kidney disease (ADPKD) and to analyze its relationship with 24-hour blood pressure pattern, plasma catecholamines and 24-hour ambulatory blood pressure monitoring were evaluated in 30 ADPKD hypertensive patients (of which 17 without and 13 with renal failure) and in 50 essential hypertensives. The groups were matched for sex, body mass index, known duration of hypertension, and clinic blood pressure. Plasma catecholamines, determined in resting position, were higher in ADPKD patients without renal failure than in essential hypertensives. Nighttime diastolic blood pressure was higher and the percentage day-night difference in mean blood pressure was lower in hypertensives with ADPKD compared to patients with essential hypertension. Blood pressure was significantly correlated with plasma noradrenaline in ADPKD patients, independently of renal function. No significant differences were observed between ADPKD patients with and without renal failure, with respect to plasma catecholamines, 24-hour daytime and nighttime ambulatory blood pressures and the percentage day-night difference in mean blood pressure.     

Maintenance of maternal diet-induced hypertension in the rat is dependent on glucocorticoids

Recent epidemiological evidence suggests that adult cardiovascular risk is determined by birth weight and factors that influence birth weight, such as maternal nutrition. Data from animal models suggest that an interaction between nutrition and glucocorticoid hormones "programs" increased risk of adult hypertension. Increased fetal exposure to maternal glucocorticoids that is proposed to occur from a reduction in the placental barrier to maternal glucocorticoid, 11beta-hydroxysteroid dehydrogenase, is suggested to program hypertension in the resultant offspring from both glucocorticoid-treated and maternally protein-restricted rats. The extent to which postnatal glucocorticoid stimulation may influence the progression of hypertension in the offspring from protein-restricted rat dams was assessed in 6-week-old male Wistar rats, prenatally exposed to either an 18% casein (control) or 9% casein (low protein) diet. Rats from each dietary group were sham operated, adrenalectomized or adrenalectomized, and treated with 20 mg corticosterone/kg body weight per day. Before surgery, systolic blood pressure was significantly higher in the low protein-exposed rats compared with controls (165+/-3.8 versus 142+/-3.3 mm Hg, P<.0001). Adrenalectomy of the low protein-exposed animals significantly reduced the blood pressure to control levels, while corticosterone replacement restored the hypertensive state. No effect of adrenalectomy on blood pressure was observed in 18% casein controls. In both dietary groups adrenalectomy decreased brain, but not hepatic, glucocorticoid-sensitive enzyme activities and corticosterone treatment elevated activities of all enzymes. The data suggest that maternal diet-induced hypertension is dependent on an intact adrenal gland postnatally and that glucocorticoids are key trophic agents in maintaining the high blood pressure.     

The effect of minoxidil on blood pressure and plasma renin activity in patients with essential and renal hypertension

The effect of the new vasodilator, minoxidil, on blood pressure and plasma renin activity was studied in 21 hypertensive patients: 12 patients with essential and 9 with renal hypertension. The average maximum dosage of minoxidil was 27.9 +/- 6.0 mg/day (M +/- SD). Average duration of treatment was 84.5 days. During the observation period the average systolic blood pressure fell from 195 +/- 18 to 159 +/- 7 mm Hg (M +/- SD), and the mean diastolic blood pressure fell from 120 +/- 8.3 to 92.5 +/- 8 mm Hg (p less than 0.01). These patients had been treated earlier with other antihypertensive agents, such as reserpine, saluretics, hydralazine, alpha-methyldopa, and clonidine, without any significant reduction in blood pressure. Before treatment, plasma renin activity after resting was 59 +/- 6.4 ng/ml/16 h (M +/- SE) and after saluretics and orthostasis 89 +/- 12.7 ng/ml/16 h. After treatment, the decline in renin value after resting was statistically significant: 42.7 +/- 3.3 ng/ml/16 h (p less than 0.05), and the stimulated renin had fallen to 70 +/- 3.4 ng/ml/16 h (p greater than 0.1). A comparison of the renin stimulation values of patients with renal hypertension also revealed a significant reduction (p less than 0.01). Side effects which appeared at a daily dose of 15 to 30 mg consisted mainly of tachycardia and fluid retention and could be controlled by the administration of propranolol and chlorthalidone. In 5 women and in 1 man was observed a cosmetically disturbing, reversible hypertrichosis. Orthostatic hypotension was observed in one patient. Minoxidil is an effective antihypertensive agent. However, because of its side effects, it generally must be administered with beta-receptor blocking agents and saluretics. It is possible that its blood pressure lowering effect is due, at least in part, to a suppression of the plasma renin activity.     

Hemodynamic characteristics of young men at risk for hypertension at rest and during laboratory stressors.

Examined hemodynamic activity at rest and during arithmetic and cold pressor in 105 male medical students varying in risk for hypertension. Classification into low-, moderate-, and high-risk groups was based on resting systolic blood pressure (SBP) and parental history of essential hypertension (PH). Dependent variables were SBP, diastolic BP (DBP), heart rate, and rate-pressure product (RPP). Progressively greater hemodynamic activity was seen across risk groups at rest and during the tasks. Risk groups differed significantly in SBP, DBP, and RPP at baseline and in size of response to mental arithmetic but not cold pressor. These relationships were either absent or weaker when using either risk factor alone to form risk groups. Hemodynamic reactivity to mental stress appears to be predicted better by a combination of resting SBP and hypertension than by either risk factor alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Copper electroplating of non-aqueous elastomeric impression materials: a subjective appraisal of their platability

Adolescent students of a rural block were studied to find out variation in blood pressure in relation to sex, caste and socioeconomic status. Females had significantly higher mean values of blood pressure; both systolic and diastolic. There was significant variation in systolic blood pressure amongst adolescents of various socio- economic classes. Prevalence of systolic hypertension (95 percentile) was higher in adolescents of upper middle social class and diastolic hypertension in Prestige castes. It is suggested that screening for hypertension should be done at school leaving age and high risk adolescents should be advised about periodic check-up, proper diet, salt restrictions and exercise so that frank hypertension could be prevented in adulthood.     

A series of self-measurements by the patient is a reliable alternative to ambulatory blood pressure measurement

BACKGROUND: Several studies have reported overdiagnosis and overtreatment of hypertensive patients, especially in borderline hypertensives. AIM: To find a blood pressure measurement procedure that reduces the risk of misclassification to an acceptable level. METHOD: Comparative, prospective study over seven months of primary care patients with elevated initial blood pressures. Blood pressure measurements made by general practitioners (GPs), practice nurses, and patients were compared with ambulatory blood pressure measurements. RESULTS: Ninety-nine patients completed the study. Mean differences (systolic blood pressure) between different measurement procedures and ambulatory measurement ranged from +10 mmHg (doctor) to -1 mmHg (patient), and (diastolic) from +4 mmHg (doctor) to -2 mmHg (patient). Standard deviations of mean differences ranged from 12 mmHg (doctor/systolic) to 10 mmHg (patient/systolic), and from 8 mmHg (doctor/diastolic) to 7 mmHg (patient/diastolic). CONCLUSION: Self-measurements by the patient appear to be a reliable alternative to ambulatory blood pressure measurement. In diagnosing and managing mild hypertension, we recommend the use of a valid self-measuring device.     

Blood pressure in tenth-grade students: results from the Chicago Heart Association Pediatric Heart Screening Project

This report is based on 13,231 tenth-grade students who participated in the Chicago Heart Association Pediatric Heart Screening Project. The blood pressures of these fifteen and sixteen-year-olds were analyzed with respect to sex, race, adiposity, pulse rate, and father's educational attainment. The mean systolic blood pressure was higher in boys than girls by nearly 5 mm Hg, but mean diastolic blood pressure was lower by less than 1 mm Hg. Black tenth-graders had higher mean diastolic blood pressure than whites; the difference in systolic blood pressure was not statistically significant. Adiposity and resting pulse rate were positively correlated with systolic blood pressure and, to a lesser degree, with diastolic blood pressure. After taking adiposity and pulse rate into account, father's educational attainment had a small but statistically significant negative association with diastolic blood pressure in white but not in black students. Nearly 5 percent of students were recalled for a second test because the initial screening blood pressures equaled or exceeded 150 mm Hg systolic or 90 mm Hg diastolic, and almost half of students at the recall examination continued to have pressures of 145/85 or greater.     

Ultrasound diagnosis in primary staging of head-neck tumors

The purpose of this study was to determine the minimum number of consecutive blood pressure cuff inflations required to obtain seated stable resting baseline measurements of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP). Sixty male college students aged 18 to 31 years volunteered as study subjects. Thirteen observations of HR, SBP, DBP, and MAP were recorded at 90-second intervals for each subject using a Critikon-Dinamap monitor. Stable readings for SBP and MAP were obtained in 6.5 minutes or 3 to 5 cuff inflations in the population tested. Using this procedure, additional age- and gender-specific norms could be established for normal and hypertensive subjects. Knowing the approximate quantity and frequency of blood pressure cuff inflations needed to generate baseline minimum measurements of HR, SBP, DBP, and MAP will be helpful in studies of cardiovascular reactivity, as well as for clinical and psychophysiologic treatment of hypertension.     

Effect of bilateral lesions of the solitary tract nucleus on arterial blood pressure in spontaneously hypertensive rats of Okamoto strain

Bilateral electrolytic lesions of the solitary tract nucleus in control Wistar albino rats as well as in Okamoto rats with spontaneous arterial hypertension caused a considerable rise in the arterial blood pressure. Quantitative comparison of blood pressure rise in normotensive and hypertensive rats demonstrated that the rise in the systolic and mean blood pressure was not significantly different in both groups of animals. However, the rats with spontaneous hypertension reacted, with a greater rise in the diastolic pressure. A characteristic feature observed in the normotensive rats was a high rise in pulse pressure following lesion of the solitary tract nucleus while in the rats with spontaneous hypertension this change was not found. The authors conclude that increased peripheral vascular resistance in the rats with spontaneous hypertension is not due to inhibition or resetting of the baroreceptor reflex.     

Hypertension and the obstetrician-gynecologist

Hypertension is a major risk factor for cardiovascular-related morbidity and death. Antihypertensive therapy markedly reduces the risk caused by elevated blood pressure. Earlier treatment of hypertensive patients should reduce deaths and morbidity even further. The obstetrician-gynecologist has the opportunity and responsibility to identify hypertensive patients early in the course of their disease. He must also confront the problem of elevated blood pressure associated with the use of oral contraceptives. In addition to its impact on the general population, chronic hypertension presents special problems during pregnancy. Pregnant women with elevated blood pressure have an increased fetal mortality rate and develop pre-eclampsia more frequently and earlier than nonhypertensive women. Antihypertensive treatment possibly increases fetal survival; when used appropriately, it definitely does not decrease fetal salvage. The appropriate use of antihypertensive therapy during pregnancy requires an understanding of the mechanism of action of these agents and recognition of side effects, especially those important during pregnancy.