Spontaneous white matter lesion in brain of stroke-prone renovascular hypertensive rats: a study from MRI, pathology and behavior

Hypertension is considered one of the most important controllable risk factors for white matter lesion (WML). Our previous work found that stroke-prone renovascular hypertensive rats (RHRSP) displayed a high rate of WML. This study aimed to investigate the WML in RHRSP from MRI, pathology and behavior. RHRSP model was established by two-kidney, two-clipmethod and kept for 20 weeks. WML was decteted by magnetic resonance imaging (MRI) and loyez staining. Cognition was tested by morris water maze (MWM). Vascular changes were observed by HE staining on brain and carotid sections. Ultrastucture of blood brain barrier (BBB) were observed by transmission electron microscope. Immunofluorescence was used to detect albumin leakage and cell proliferation. T(2)-weighted MRI scans of RHRSP displayed diffuse, confluent white-matter hyperintensities. Pathological examination of the same rat showed marked vacuoles, disappearence of myelin and nerve fibers in white matter, supporting the neuroimaging findings. Spatial learning and memory impairment were observed in RHRSP. The small arteries in brain exhibited fibrinoid necrosis, hyalinosis and vascular remodeling. BBB disruption and plasma albumin leakage into vascular wall was observed in RHRSP. Increased cell proliferation in subventricular zone was seen in RHRSP. RHRSP demonstrated spontaneous WML and cognitive impairment. Hypertensive small vessel lesions and BBB disruption might paly causative factors for the onset and development of WML. The characteristic features of WML in RHRSP suggested it a valid animal model for WML.

Compliance with antihypertensive therapy after renal artery stenting

Hypertension is an important clinical endpoint after renal artery revascularization for renal artery stenosis (RAS). Medication compliance is a critical determinant of blood pressure control. Although factors influencing compliance are known in essential hypertension, they have not been evaluated in studies investigating renal artery revascularization. The aim of this study was to assess the determinants of compliance to antihypertensive therapy in patients with RAS following renal artery stent placement (RASP). A cross-sectional study evaluating blood pressure, antihypertensive medications, quality of life, compliance, and determinants of compliance to antihypertensive therapy was undertaken in 112 patients undergoing RASP. Additionally, cardiovascular risk factors, antihypertensive medications, and cardiovascular history were reported. Self-reported compliance was 79% +/- 24% (scale of 0% [none] to 100% [complete] compliance) in patients after RASP. Determinants of compliance by multivariate analysis included physical symptoms, which correlated negatively to compliance and included loss of appetite (r2 = 0.26, P < 0.0001), dizziness (r2 = 0.06, P < 0.01), and cough (r2 = 0.03, P < 0.05). Systolic blood pressure correlated positively with compliance (r2 = 0.03, P < 0.05). The number or class of antihypertensive medications did not influence compliance. Patients' physical symptoms and level of systolic blood pressure, rather than the number or class of medications, influence compliance in patients with continued hypertension after RASP. Attention to physical symptoms may help to improve blood pressure control in this population.

Reproducibility and validity of quality of life measurements in hypertensive patients on stable medication

OBJECTIVE

The reproducibility and validity of a hypertension-specific questionnaire and a genetic health questionnaire (the MOS Short-form General Health Survey) were evaluated for measuring the quality of life in a randomized controlled trial comparing balloon angioplasty and long-term medication in patients with renovascular hypertension.

METHODS

The health questionnaires were filled out by 97 patients with hypertension on stable medication. The reproducibility of the questionnaires was assessed by intraclass correlation coefficients (ICCs). Pearson's correlation coefficients were calculated between the scales of the questionnaires to evaluate the validity.

RESULTS

Medication had been changed to eliminate side-effects in an earlier phase of treatment. Only 7% of the patients reported non-compliance with the medication regime. Most patients suffered from physical symptoms, but the impact of long-term antihypertensive medication on the quality of life was not substantial. The reproducibility was good for most scales (ICC > 0.70), except for the role and social functioning scales. All correlations between the scales of the questionnaires were statistically significant and no contradictory correlations were found.

CONCLUSIONS

The health questionnaires together form a reproducible and valid instrument for measuring the quality of life of hypertensive patients on stable medication.

Quality of life in elderly renovascular hypertensive patients

This study assessed perceived quality of life in elderly, surgically managed renovascular hypertension patients. Twenty-three patients, aged 55 to 90 years, with unilateral or bilateral aortorenal bypass grafting or transrenal or transaortic endarterectomy, participated in the study. The Sickness Impact Profile was used to measure perceived quality of life. Overall, elderly, renovascular hypertension patients, at least 1 year postoperatively, experienced quality of life comparable to persons with other serious chronic illnesses; and females reported significantly poorer quality of life than males.

Beta-blocker effects on 24-h activity in normotensive and renovascular hypertensive baboons

Spontaneous motor activity of normotensive and renovascular hypertensive baboons was measured during oral dosing with the beta-adrenergic antagonists atenolol HCl (2.6 mg/kg/day) and d,l-propranolol HCl (6.8 mg/kg twice daily) in separate studies. Each study administered active drug for 21 consecutive days. Piezoelectric monitors sensitive to movement were worn continuously by the baboons. Propranolol decreased overall 24-h average activity during the third week of dosing in normotensive baboons but not in renovascular hypertensive baboons. The greatest reductions in activity averaged 20% at those times of day corresponding to the second daily drug dose both in normotensive baboons and, at this time of day only, in the majority of hypertensive baboons. Activity decreases reversed to baseline levels when propranolol was discontinued. For atenolol, most normotensive but no hypertensive baboons showed decreases in activity at the time of day corresponding to the daily drug dose.

Behavioral performance effects of verapamil in normotensive and renovascular hypertensive baboons

Behavioral performances of normotensive and hypertensive adult male baboons were tested before, during, and following chronic oral dosing with verapamil. Performances during a five-color simultaneous match-to-sample task were measured for two doses (2.0, and 3.2 mg/kg/day) and vehicle. Each dose was administered for 21 consecutive days preceded and followed by 14-day baseline and recovery periods, respectively. Choice reaction times increased by 9% during the lower dose of verapamil, compared to vehicle; choice reaction times were unchanged at the higher dose. At baseline and during vehicle administration, the yellow and white stimuli were the most difficult to discriminate correctly; discrimination of these colors was slightly impaired by the lower, but not the higher dose of verapamil. Verapamil's behavioral effects were not modulated by blood pressure changes since both baboon groups showed equivalent changes in behavioral performance, but only renovascular hypertensive baboons showed blood pressure decreases. Verapamil appears to be an effective hypotensive and does not produce profound psychomotor impairment at clinically used doses during the first weeks of treatment.

Performance of baboons under a repeated acquisition procedure during chronic oral exposure to atenolol and propranolol

Repeated acquisition behavioral performances of normotensive and renovascular hypertensive baboons were tested before, during, and following chronic oral dosing with the beta-adrenergic antagonists atenolol HCl (2.6 mg/kg/day PO), and d,l propranolol HCl (6.8 mg/kg twice daily PO) in separate studies. Each study administered active drug for 21 consecutive days preceded and followed by 14-day baseline and recovery periods, respectively. Animals pressed five keys in sequence for food reinforcement during daily experimental sessions which consisted of alternating acquisition (new sequence learning) and performance (previously learned) task components. Atenolol increased response latencies during acquisition in comparison to performance components, and during early portions of sessions. Propranolol also increased response latencies during acquisition components in early periods of sessions, but fewer dependent measures were affected, and the magnitude of increases in response latencies was smaller (12% +/- 5 SEM) as compared with atenolol (47% +/- 13). Test doses of phencyclidine HCl (PCP) increased latencies to the same degree as atenolol. PCP markedly reduced accuracy, while atenolol or propranolol did not. Blood pressures remained stable under atenolol, and decreased by approximately 10-15 mmHg under propranolol. No differences between renovascular hypertensive and normotensive baboons were found as a function of drug conditions. Drug effects were not dependent on plasma propranolol concentration.

[Behavioral factors in the problem of treating arterial hypertension]

The paper deals with the role of the psychological factors in the control of arterial hypertension in the population. The attitude of the population towards their own health and possible medical intervention--these are the factors. It is proved that the negative attitude can low down the efficiency of the public health effort in the revealment and systematic management of hypertensives. Special attention is paid to the discussion of the role of the psychological factors in the pathogenesis of the essential hypertension. Personality traits of the patients with different forms and course of arterial hypertension (symptomatic included) are considered. Strategy and psychological intervention methods in essential hypertension control in order to increase the treatment efficiency are also discussed. The importance of the multidisciplinary approach which envisages routine hypertensive drugs, beta-blocker, psychotropic agents and relaxatiion technique, causal-pathogenetic psychotherapy methods, psychosocial intervention is stressed.