Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Renin-associated, chronic psychosocial hypertension of 150-160 mmHg develops in groups of mice interacting socially in complex population cages. 2. The blood pressures of 16 males in a cage were measured and an intraperitoneal injection of the angiotensin coverting enzyme inhibitor captopril (SQ 14,225) was given. Three hours later blood pressures were measured again. 3. During the first 3 weeks of psychosocial hypertension SQ 14,225 was without effect. But at 1 month and subsequently up to 7 months, SQ 14,225 reduced blood pressure to the normal range of 120-130 mmHg. 4. Plasma renin activities were not related to the extent of blood pressure reduction by SQ 14,225. Hence other factors in addition to the renin-angiotensin mechanism play a part in maintaining chronic psychosocial hypertension.
 ...
PMID:Effects of an angiotensin converting enzyme inhibitor on psychosocial hypertension in mice. 23 19

Fifty male albino rats were used to study how social factors (animals kept in large groups with playing-cage character, or in social isolation by solitary maintenance) are reflected in the responsiveness of cerebro-visceral regulation processes to chronic stress exposure. The following results were obtained: Animals kept from the 12.-30. week of life in social companionship and, additionally, exposed to chronic stress influences, proved to be greatly resistant to permanent load. This effect is referred to the rich supply of social afferentations and to the pronounced stimulation of proprioreceptive reafference as a result of social communication and motor activity. Animals kept, after preceding large-group maintenance, in social isolation from the 17.-30. week and simultaneously being exposed to the same stress influence as the animals in the playing cage, showed symptoms of an early stage of neurotically induced, arterial hypertension. Here, the chronic lack of socially determined, adequate environmental afferentation and of proprioreceptive reafference, as was typical of solitary maintenance, proved to be a factor enhancing the pathological predisposition of the organism under extreme environmental conditions.
 ...
PMID:[Significance of different social factors active in the course of ontogenesis, for the effectiveness of chronic stress influences upon cerebro-visceral regulation processes of albino rats]. 124 30

Studies were undertaken to evaluate the fundamental conditions for a low-intensity voluntary wheel running model in rats and its chronic effects on health indexes. Male Fischer rats (SPF) 5 weeks of age were housed in individual sedentary conditions or in individual wheel-cage units which allowed free access to voluntary wheel running for 8 months. Voluntary running averaged 640 +/- 198 m/day, reached a peak (965m) at the 2nd month and waned over time, reaching a plateau after the 6th month (about 400-500m). Exercising rats consumed more food (+23%), but exhibited decreased body weight gains (-9%), suggesting a remarkable lowering of fat. A lowering effect on resting blood pressure (-5%) was also recognized. In addition, preventive effects on oxygen toxicity and effective bactericidal activity of neutrophils and pulmonary alveolar macrophages (PAM) were suggested. Although the amount of exercise in this study was the smallest of the other preceding ones conducted with a voluntary wheel running model, many potential health benefits were recognized. Such health promoting and protective effects by low-intensity voluntary exercise and the harmfulness of forced exercise in rats have been reported in researches on cancer, lowering fat and hypertension. Therefore it is important to set up conditions for low-intensity voluntary running. It was also demonstrated by this study that strictly controlled environmental conditions, such as room temperature and humidity, a 12-hr light-dark cycle and prevention of infection and psychological stress to rats, as well as using male rats, which are more inactive, were important factors to establish this model.
 ...
PMID:[Conditions for low-intensity voluntary wheel running in rats and its chronic effects on health indexes]. 128 62

The spontaneously hypertensive rat (SHR) is behaviorally hyperactive relative to the Wistar-Kyoto rat (WKY). By breeding SHR with WKY, followed by inbreeding, two new strains have been developed in which hypertension seems to be separated from hyperactivity to novel stimuli: the WKHT and the WKHA strains. The main purpose of the present study was to determine which behavioral characteristics of SHR have been dissociated from the hypertensive trait in the WKHA strain. Male SHR, WKY, WKHT, and WKHA were subjected to three protocols: 1) Two forced-exploration tests, where the results showed that both the SHR and the WKHA rats were hyperactive. 2) A free-exploration open field, where the SHR was more active than the other strains, showing shorter latencies to leave the home cage, spending more time in the field, ambulating and rearing more. Furthermore, the WKHT behavior was more similar to the SHR behavior than the WKHA behavior. 3) A two-component schedule of reinforcement, where one component (fixed-interval 2 min) was signaled by houselight on and the other (extinction, EXT) by houselight off. In this test, the SHR behavior was markedly different from that of the three other strains: the fixed-interval scallop, the accelerated responding towards the end of the interval, was steeper in SHR than in the other groups. The SHR emitted more responses during the extinction component of the schedule. The SHR hyperactivity was dependent upon the reinforcement value of the water deliveries and was increased even further by sensory-reinforcing respones feedback lights. Thus, the hyperactivity of the WKHA strain seems to be less pervasive than that of the SHR.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Behavior of hypertensive and hyperactive rat strains: hyperactivity is not unitarily determined. 152 13

We studied the recent alcohol consumption and other possible precipitating factors in 99 consecutive patients (53 men and 46 women) all under 65 years of age with sustained re-entry and automatic supraventricular tachyarrhythmias and compared them with those of two groups of controls. One control group was derived from the Emergency Room patients and matched for age and sex; the other group (44 men, 22 women, mean age 48.7 years) was randomly selected from the general out-of-hospital population. There were 50 patients with supraventricular tachycardia, 30 with atrial flutter, and 19 with paroxysmal atrial tachycardia. Coronary heart disease (14% of patients), hypertension (10%), and dilated cardiomyopathy (6%) were the most prevalent cardiovascular diseases associated with the arrhythmias. The self-reported alcohol consumption of patients with arrhythmias during the week preceding the arrhythmia did not differ significantly from that of hospital or population controls, although significantly more patients than controls had liver enzyme levels above normal; neither were there any significant differences between the groups regarding prevalence for alcoholism as judged by the CAGE questionnaire. The results were essentially similar when patients with supraventricular tachycardia and those with intra-atrial tachyarrhythmias (flutter and paroxysmal tachycardia) were separately compared with the controls. We conclude that alcohol consumption, although a risk factor for atrial fibrillation, is not associated with the induction of other supraventricular tachyarrhythmias in patients of working age.
 ...
PMID:Alcohol consumption of patients with supraventricular tachyarrhythmias other than atrial fibrillation. 187 80

The effect of maternal strain on reactivity to acute stress was studied in F1 reciprocals produced by crossing the spontaneously hypertensive rat (SHR) with its normotensive progenitor, the Wistar-Kyoto (WKY). This F1 generation, known as the borderline hypertensive rat (BHR), is genetically predisposed to develop hypertension in response to chronic stress or high dietary sodium. Reciprocals, considered to be genetically equivalent aside from sex-linked traits, differ in strain of dam during intrauterine and preweanling development. At 17 weeks of age, reciprocal F1 males did not differ in open-field behavior (squares crossed, rearings, and defecation measured over 3 days in 15-min sessions) or in home-cage measurements of mean arterial pressure (MAP) and heart rate (HR). However, different patterns of cardiovascular reactivity were displayed to transfer and footshock. While WKY-mothered rats reacted with graded pressor responses, SHR-mothered rats responded maximally to transfer, showed no additional increase to footshock, and maintained peak responding after footshock was terminated. Such reactivity differences may mediate the impact of environmental variables on the genetic disposition to hypertension.
 ...
PMID:Dam strain affects cardiovascular reactivity to acute stress in BHR. 232 28

The purpose of this study was to assess the effects of chronic insulin infusion on blood pressure and urinary sodium excretion in Wistar rats. Fifteen Male Wistar rats weighing about 220 g were used. The rats were housed in metabolic cage and measured urine volume. Osmotic minipumps filled with insulin (0.57 U/day, Insulin group, n = 9) or saline (0.014 cc/day, Control group, n = 6) were implanted subcutaneously under ether anaesthesia, and blood pressure, urine volume, urinary sodium excretion (UNaV), plasma renin activity (PRA), plasma norepinephrine concentration (PNE) were measured for 4 weeks. In insulin group, there were no significant changes on plasma glucose levels, but systolic blood pressure rose significantly from 119 mmHg to 140 mmHg after 4 weeks. In this group, urine volume, UNaV, and PRA were significantly lower than those of control group and PNE was tended higher but not significant (P less than 0.1). Exogenous NE was given intravenously to assess the endogenous NE activity. Blood pressure elevation caused by exogenous NE in insulin group was suppressed significantly than that of control group. On the basis of these findings, we conclude that insulin can cause high blood pressure due to sodium retention and activation of endogenous NE.
 ...
PMID:[Insulin and hypertension--the mechanisms of high blood pressure during chronic insulin infusion]. 268 19

In unanesthetized and unrestrained rats, microinjection of L-glutamate into the posterior hypothalamus produced hypertension and tachycardia. These cardiovascular responses were mostly accompanied with behavioral excitation such as searching the cage, rearing and sniffing. The cardiovascular responses elicited by L-glutamate were attenuated by prior injection with propranolol and hexamethonium but not with glutamate diethylester, phentolamine and atropine. The behavioral responses to L-glutamate were suppressed by propranolol, hexamethonium and phentolamine. These results suggest that catecholaminergic and/or cholinergic systems in the posterior hypothalamus may be involved in the mediation of the cardiovascular and behavioral responses induced by L-glutamate.
 ...
PMID:Effect of L-glutamate, injected into the posterior hypothalamus, on blood pressure and heart rate in unanesthetized and unrestrained rats. 286 99

Responsiveness to endothelium-dependent (acetylcholine and A23187) and endothelium-independent (nitroprusside and 8-bromo cyclic guanosine 3',5'-monophosphate [cGMP]) vasodilators was examined in two vascular preparations from hypertensive and normotensive mice. CBA Agouti mice were made hypertensive by exposure to social stress in a complex population cage. After 2 months, the hindquarter vascular bed was pump-perfused at a constant flow with plasma substitute to evaluate changes in perfusion pressure, and helical strips of aorta were suspended in muscle baths for measurement of isometric force generation. Tissues were treated with methoxamine to induce contractile tone. Threshold dilator responses to acetylcholine were elicited at a significantly lower dose in the hindquarters of hypertensive mice than in those from normotensive mice, indicating increased vasodilator sensitivity. In contrast, vasodilator responsiveness to nitroprusside in hindquarters of hypertensive mice did not differ from that in hindquarters of normotensive mice. Aortas from hypertensive mice were more sensitive (lower ED50) to the relaxant effects of acetylcholine and A23187 than those from normotensive mice. The relaxant effects of nitroprusside and 8-bromo cGMP on aortas from hypertensive mice were not significantly different from those in normotensive aortas. Aortic strips that had been rubbed on the lumen surface with a wooden stick did not relax to acetylcholine or A23187. In aortas that were not initially contracted with methoxamine, acetylcholine and A23187 caused small contractions from baseline. The magnitude of these contractile responses were potentiated after removal of the endothelium, and the potentiation was greater in aortas from hypertensive mice. These results demonstrate an increased responsiveness to endothelium-dependent vasodilators in this psychosocial model of hypertension.
Hypertension 1987 Mar
PMID:Increased vasodilator responses to acetylcholine in psychosocial hypertensive mice. 302 55

The combined transplantation of heart and lungs, first done successfully by the Stanford Team (USA) in 1982, at present seems to be superseding lung transplantation alone, and has broadened the indications of heart transplantation to include terminal heart failure with fixed pulmonary arterial hypertension. After reviewing the causes for failure in lung transplants, the authors stress the superiority of heart-lung transplants compared to isolated lung transplantations: healing of the tracheal anastomosis, ease of detection of rejects by endomyocardial biopsy and the lack of inhomogeneity of the ventilation/perfusion ratios. This operation still poses problems of surgical technique as the mediastinal nerves need to be preserved and the risk of haemorrhage linked to the mediastinal dissection or to the eventual pulmonary separation under cardiopulmonary bypass is important. Donor subjects for cardiopulmonary transplantation are rare as they ought to have a thoracic cage of matching size to the recipient and to be free of pulmonary infection and trauma. The post-operative complications are essentially those of immediate haemorrhage, graft rejection, pulmonary oedema and infection. The late complications are coronary atherosclerosis and bronchiolitis obliterans. The indications of such a transplant are currently reserved for primary or secondary pulmonary hypertension and to respiratory failure with a normal thoracic cage and ventilatory mechanics.
 ...
PMID:[Heart-lung transplantation]. 310 71


1 2 3 4 5 6 7 8 9 10 Next >>