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Biomedical subjects

P Mulder

Publications and source records attributed to P Mulder.

At least 55 records · Page 3Linked to original sources
PubMed1995

Radiographic absorptiometry of the phalanges in healthy children and in girls with Turner syndrome.

Although bone mineral status in children has been measured with various techniques, information about development of the actual bone mass density during childhood and adolescent growth is scarce. Our modified radiographic absorptiometry (RA) determines bone mass density (BMaD) three dimensionally at the diaphyseal and metaphyseal site of the middle phalanx of the left second digit, representing predominantly cortical (50% site) and trabecular bone compartments (25% site), respectively. The objectives of this study were to establish reference curves with 95% prediction intervals of BMaD in relation to bone age (BA) during childhood and adolescence (N = 303) determined by RA. The specific effects of female puberty on BMaD were studied comparing the values of 110 untreated girls with Turner syndrome (TS) with those of the female reference group. For either sex, a piecewise linear model with one inflection point (IP) was postulated for the relationship of both the 25% and 50% site with BA. The IPs appeared at exactly the same BA (11.5 "years") for both the 25% and 50% site in boys and for the 25% site in girls. However, in girls the 50% site IP appeared 0.25 "years" later. All BMaD values to the left of the IPs showed little increase with age. In contrast, the slopes to the right of the IPs showed in both genders regression coefficients of approximately 0.05 for the 25% site. For the 50% site, the regression coefficient in girls was markedly higher (0.075) than in boys (0.058), resulting only in girls in a significant difference between the 25% and the 50% site to the right of the IP (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

Pubertal serum lipoprotein (a) and its correlates in Belgian schoolchildren.

BACKGROUND: Serum lipoprotein (a) (Lp(a)) is an independent risk factor for premature coronary artery disease in Caucasians. Generally Lp(a) serum levels remain fairly constant throughout an individual's life, but are presumably modulated by sex hormones. This study documents the distribution and correlates of serum Lp(a) during sexual maturation in Belgian children. A comparison with Lp(a) levels in Belgian adults is made. METHODS: Serum Lp(a), lipid and apolipoprotein A-I and B levels were determined cross-sectionally in 266 Belgian schoolchildren and adolescents in relation to sexual maturation, anthropometrics and socioeconomic status. Sexual maturity was scored according to Tanner's classification. RESULTS: Median Lp(a) levels were 82, 117, 110, 100 and 73 mg/l at the five subsequent genital development stages in boys (ANOVA, P = 0.816), and 73, 78, 204, 110 and 114 mg/l at the five breast development stages in girls (ANOVA, P = 0.087). The Lp(a) distributions in boys and girls were skewed to the right, overall medians being 82 and 94 mg/ml (P = 0.2537). The 90th and 95th percentiles were 515 and 712 mg/l respectively. The geometric Lp(a) mean in children was significantly higher compared to that in 683 sex-matched Belgian adults (89 mg/l versus 69 mg/l, P = 0.006). Multiple linear regression pointed out that developmental age, chronological age, body mass index and/or systolic blood pressure predicted serum lipid and apolipoprotein levels, but none of the Lp(a) variance. CONCLUSION: Pubertal stage was not correlated with Lp(a) levels in Belgian schoolchildren, supporting the contention that serum Lp(a) is predominantly genetically controlled.

Adolescent↗
PubMed1995

Treatment of post-menopausal osteoporosis with a combination of growth hormone and pamidronate: a placebo controlled trial.

OBJECTIVE: It is known that growth hormone can induce accelerated bone turnover in GH deficient people as well as healthy elderly people. In this study we examined the effect of recombinant human GH (rhGH) on bone mineral mass and bone turnover in the presence of the bone resorption inhibiting agent, pamidronate. Effects on body composition were also studied. METHODS: Twenty-one post-menopausal osteoporotic women were treated with the bisphosphonate pamidronate during 12 months. During the initial 6 months rhGH (0.0675 IU/kg, 3 times/week) was administered in a placebo controlled fashion (10 vs 11 patients). MEASUREMENTS: Bone mineral content (BMC) of the lumbar spine and femoral neck was measured with dual-energy X-ray absorptiometry and BMC of the distal and proximal forearm with single-photon absorptiometry. Body composition was measured with bioelectrical impedance and total body dual-energy X-ray absorptiometry. Serum IGF-I and biochemical indices of bone turnover were also measured. RESULTS: The group treated with rhGH showed a two to three-fold increase in serum IGF-I levels. No effects on bone mineral mass were observed in the group treated with rhGH, either after the initial 6 months of treatment with rhGH or after the total period of 12 months. In women treated with pamidronate, however, a consistent increase of about 5% at the lumbar spine and somewhat less in the distal forearm was reached from 6 months onwards. In neither group was any change observed in BMC at the femoral neck or forearm. Compared to baseline, the biochemical measurements of bone turnover showed a decrease of about 50% in the pamidronate treated group, but this effect was blunted in the group additionally treated with rhGH. The body composition measurements showed clear effects of rhGH administration: a decrease in fat mass of about 5% and an increase in lean body mass of about 3%. However, these effects disappeared after the treatment with rhGH was stopped and both fat mass and lean body mass returned to initial values. CONCLUSIONS: The present study suggests that treatment with rhGH blunted both the pamidronate induced accumulation of bone mineral mass and the reduction of biochemical markers of bone turnover. Furthermore, the positive effect of rhGH on body composition disappears completely after cessation of treatment with rhGH.

Aged↗
PubMed1995

Accuracy of an oscillometric automatic blood pressure device: the Omron HEM403C.

The purpose of this study was to assess the accuracy of the Omron HEM403C blood pressure (BP) device and to study whether this accuracy was affected by subject-related factors such as BP level and age. A comparison was made with a Hawksley random zero sphygmomanometer. BP was measured with both meters connected to one arm-cuff by means of a T-connector. To assess the level of agreement of the Omron HEM403C with the random zero meter, BP was measured in 212 subjects. Systolic and diastolic readings with the Omron HEM403C were on average 1 mmHg (s.d. 9, 95% CI 0.4-2.2) and 4 mm Hg (s.d. 8, 95% CI 3.6-5.1) respectively, higher than those with the random zero meter. The Omron HEM403C underestimated SBP compared with the random zero at higher SBP levels and overestimated SBP at lower SBP levels. The Omron meter overestimated the diastolic pressure at all DBP levels and the diastolic difference was not related to the DBP level. A multiple linear regression analysis demonstrated that the SBP level and not age was the factor that independently influenced the systolic difference between the meters. According to the criteria of the British Hypertension Society the Omron HEM403C is accurate enough to be recommended for those clinical and research purposes that are in need of automatic measurements.

Adolescent↗
PubMed1994

Course of bone mass during and after hormonal replacement therapy with and without addition of nandrolone decanoate.

A total of 33 women with postmenopausal osteoporosis were matched pairwise by age, years since menopause, and body mass index and randomized to receive either cyclic estrogen-progestagen replacement treatment (group 1) or the same treatment plus nandrolone decanoate (ND; group 2). Both groups were treated during 3 years and subsequently followed for another year off treatment. A year after cessation of the treatment the distal forearm bone mineral content in group 2 was significantly higher than that in group 1. Bone mass measurements in the axial skeleton already showed a significant difference in favor of group 2 after 3 years treatment, which persisted during the year off treatment. The decline in lumbar bone mineral mass and density in the 1 year off treatment was similar in both groups. Correction for body mass did not change these results. Bone turnover parameters did not show significant differences between the two groups after cessation of treatment. A higher muscle mass, induced by ND, could partly explain the differences between the groups since even 1 year after treatment was stopped an increased serum creatinine level was still observed in group 2.

Aged↗
PubMed1993

Comparison of the second and third oscillatory potentials with oscillatory potential power in early diabetic retinopathy.

We used an oscillatory potential power method (a measure of the summed oscillatory potential activity) based on fast-Fourier transform analysis to study the oscillatory potentials in early diabetic retinopathy. The method was used in 29 diabetic patients with no ophthalmoscopically visible diabetic retinopathy, 29 diabetic patients with early signs only and 27 control subjects. The reduction in oscillatory potential power was compared with the reduction in the second and third oscillatory potential amplitudes and increase in implicit time in the diabetic patients. The amplitude of the second oscillatory potential was slightly more resistant to diabetic retinopathy than was the amplitude of the third oscillatory potential. Because the oscillatory potentials were detected by means of a high-resolution technique, their implicit times seem to be as discriminating as the oscillatory potential power in the detection of early diabetic retinopathy.

Diabetic Retinopathy↗
PubMed1993

Intratracheal perfluorocarbon administration as an aid in the ventilatory management of respiratory distress syndrome.

BACKGROUND: Respiratory distress syndrome carries a high morbidity and mortality when treated with mechanical ventilation with positive end-expiratory pressure. Perfluorocarbon liquids are employed in liquid ventilation due to low surface tension and high gas solubility. To assess whether intratracheal administration of the perfluorocarbon, perflubron, in combination with conventional mechanical ventilation could be of therapeutic benefit in respiratory distress syndrome, the authors tested the effects of different doses of intratracheal perflubron administration on gas exchange and lung mechanics in adult animals with respiratory failure during a 6-h observation period. METHODS: Respiratory failure was induced in 30 rabbits by saline lung lavage (arterial oxygen tension < 100 mmHg at 100% oxygen with the following ventilator settings: tidal volume, 12 ml.kg-1; respiratory frequency, 30 per min; inspiratory/expiratory ratio, 1:2; and positive end-expiratory pressure of 6 cm H2O). Twenty-four rabbits were treated with different perfluorocarbon doses (3, 6, 9, and 12 ml.kg-1), and the remaining six served as controls while mechanical ventilation was continued with the aforementioned settings. Additionally, in ten healthy rabbits who were used as healthy controls, the lungs were mechanically ventilated either alone or in combination with intratracheal perfluorocarbon administration (3 ml.kg-1) for 6 h. RESULTS: In all treatment groups, arterial oxygen pressure increased significantly (P < 0.0001) in a dose-related fashion (193 +/- 40, 320 +/- 70, 353 +/- 125, and 410 +/- 45 mmHg at 15 min), and peak airway pressures decreased significantly (range, 18-23%; P < 0.0001) from pretreatment values. These findings were in contrast to those for the control group. The improvements were time-dependent in all four tested perfluorocarbon doses. However, the improvements in pulmonary parameters could be extended to 6 h only in groups treated with 9 ml.kg-1 and 12 ml.kg-1 perflubron. At the end of the 6-h period, the data for these two groups showed significantly higher arterial oxygen pressure (230 +/- 84 and 197 +/- 130 mmHg, respectively; P < 0.05) and lower inflation pressures than the pretreatment data for these groups and the data for the control group at 6 h. There were no clinically significant changes in pulmonary parameters in healthy animals due either to mechanical ventilation alone or mechanical ventilation in combination with intratracheal perfluorocarbon administration for 6 h. CONCLUSIONS: The results of this study imply that there is no association between the lung mechanics and gas exchange parameters for mechanical ventilation in combination with intratracheal perfluorocarbon administration. The data suggest that this type of perfluorocarbon administration with conventional mechanical ventilation offers a simple, alternative treatment of respiratory distress syndrome. With this technique, adequate pulmonary gas exchange can be maintained at relatively low airway pressures with high perfluorocarbon doses for several hours.

Animals↗
PubMed1993

Comparison of blood pressure and angiotensin responses to the renin inhibitor Ro 42-5892 and the angiotensin converting enzyme inhibitor enalapril in essential hypertension.

OBJECTIVE: To compare the responses of angiotensin II (Ang II) and blood pressure to the renin inhibitor Ro 42-5892 and the angiotensin converting enzyme (ACE) inhibitor enalapril. SUBJECTS: Eight non-sodium-restricted patients with mild-to-moderate essential hypertension. DESIGN: A single-blind crossover study. Ro 42-5892 (600 mg orally, once a day) and enalapril (20 mg orally, once a day) were given for 8 days before detailed investigations were carried out. METHODS: Ambulatory blood pressure was measured directly for 24 h by the Oxford technique on three occasions. Off-treatment and on day 8 of treatment with Ro 42-5892 and with enalapril. Ang II was measured by radioimmunoassay after separation by high-performance liquid chromatography. RESULTS: Plasma renin activity and Ang II were lowered by 83% [95% confidence interval (CI) 61-105] and 68% (95% CI 49-87), respectively, 0.5-1 h after Ro 42-5892, but after only 3 h values had returned to baseline. Unlike this rapid and short-term suppression of Ang II, the maximal antihypertensive response to Ro 42-5892 (fall in blood pressure 12.9/9.0 mmHg) occurred only after 6 h. Blood pressure returned to baseline after 8 h. In response to enalapril, Ang II was maximally suppressed by 63% (95% CI 32-94) after 2 h and by 83% (95% CI 76-90) after 8 h. Despite early maximal Ang II suppression, the maximal antihypertensive response to enalapril occurred only after 12 h (fall in blood pressure 25.3/16.3 mmHg). With this compound a significant antihypertensive effect was still present 24 h after dosing. CONCLUSIONS: Compared with enalapril at 20 mg once a day, repeated oral administration of a single dose of Ro 42-5892 at 600 mg caused only short-term suppression of Ang II and blood pressure. Suppression of Ang II and reduction in blood pressure were temporally dissociated, both with the ACE inhibitor and the renin inhibitor. This implies that the blood pressure lowering effect of these inhibitors is caused partly by Ang II suppression outside the circulation.

Adult↗
PubMed1993

Glomerular hyperfiltration in insulin-dependent diabetes mellitus is correlated with enhanced growth hormone secretion.

Enhanced GH secretion and hyperglycemia are suggested to play a role in the pathogenesis of glomerular hyperfiltration in insulin dependent diabetes mellitus. In this study we measured the GH response to GHRH (1 microgram/kg body weight), metabolic control, and renal function in 44 patients in order to explore a possible association between these parameters. Hyperfiltration [glomerular filtration rate (GFR) > 130 ml/min/1.73 m2] was present in 21 patients and normofiltration in 23. The duration of diabetes, plasma concentrations of renin, catecholamines, insulin-like growth factor-1 and blood glucose during renal function measurements were not different. GH response was significantly higher in patients with hyperfiltration. There was a positive relation between GH response and GFR (r = 0.51, P < 0.001) and effective renal plasma flow (r = 0.39, P < 0.01). GFR was correlated with insulin dose (r = 0.48, P < 0.001). There was no difference in glycosylated hemoglobin between the two groups. Patients with hyperfiltration used more insulin, had more frequent blood glucose values below the threshold level for activation of GH secretion, and had greater glycemic excursions than patients with normofiltration. The results suggest that GH hypersecretion and glomerular hyperfiltration are related and they support the possibility of a linkage between GH hypersecretion and glucose variability.

Adolescent↗
PubMed1992

Can nandrolone add to the effect of hormonal replacement therapy in postmenopausal osteoporosis?

Thirty-six women with postmenopausal osteoporosis (31 of them with at least one non-traumatic vertebral compression fracture) were matched pair-wise as to age, years since menopause and body mass index and randomized to receive either cyclical estrogen-progestagen replacement treatment (group 1) or the same treatment plus nandrolone decanoate (group 2). During the first year of treatment in both groups the forearm BMC (SPA) rose proximally and distally 2-3%. Over 2 years the increments of forearm BMC in both groups were up to 4.5%. Lumbar BMC (DPA) rose in both groups nearly 10% over the first year and 12-12.5% over 2 years. The cancellous bone density of L3 (QCT) showed in 6 months an increase of 21% in group 1 and 29% in group 2 to subsequently stay at that level. All these changes from the basal levels were highly significant but there were no significant differences between the two groups. These two conclusions were also drawn with regard to the induced fall of serum alkaline phosphatase (-23%), osteocalcin (-35% to -44%) and procollagen I (-15% to -22%) and of the fasting urinary hydroxyproline (-33% to -36%). No significant increase in the number of newly deformed vertebrae occurred in 2 years.

Aged↗
PubMed1992

Long-term treatment with trandolapril opposes cardiac remodeling and prolongs survival after myocardial infarction in rats.

Long-term treatment with angiotensin I converting enzyme inhibitors (ACEIs) prolongs survival in rats developing congestive heart failure after myocardial infarction (MI). In this experimental model, we investigated at regular intervals the effects of a 1-year oral treatment with trandolapril, a new ACEI, on (a) survival rate and duration and (b) hemodynamic, biological, and cardiac and vascular histomorphological parameters. Control MI rats and sham-operated trandolapril-treated and control rats were simultaneously studied. In MI rats, trandolapril significantly increased the survival rate and duration, increasing the life expectancy by approximately 6 months. It also significantly decreased the arterial blood pressure and increased diuresis. These effects occurred as soon as the treatment was started and persisted throughout the study. Trandolapril significantly limited the development of myocardial hypertrophy, decreasing the heart weight and left ventricular hypertrophic area and increasing the left ventricular myocyte nuclear density, but these effects, starting after 3-6 months, were delayed compared to the hemodynamic ones. Finally, trandolapril limited the development of myocardial (both subendocardial and subepicardial) and aortic fibrosis. It is concluded that the early pre- and afterload effects of trandolapril are initially responsible for its beneficial action on survival, whereas later the drug's antihypertrophic and antifibrotic properties together with persistent hemodynamic effects account for the prolonged survival improvement.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

Hemodynamic and morphological effects of quinapril during genetic hypertension development.

The relative contributions of the hemodynamic and morphological (vascular and cardiac) modifications induced by long-term administration of an angiotensin I-converting enzyme inhibitor, quinapril, to the drug's long-lasting preventive effects vis-à-vis genetic hypertension development (GHD) have been investigated in young spontaneously hypertensive rats (SHRs). Two groups of SHRs were given quinapril (10 mg/kg/day) or distilled water from 5 to 20 weeks of age. The drug was then stopped, but observations continued for another 7 weeks. At selected times systemic and regional hemodynamic parameters as well as cardiac and vascular morphological effects were investigated. During the treatment period, quinapril partially opposed GHD and limited the early rise in total peripheral and regional vascular resistances observed in control animals. Quinapril's partial preventive effect vis-à-vis GHD persisted, but faded after treatment withdrawal. From a morphological point of view, quinapril strongly opposed aortic wall hypertrophy as evidenced by significant reductions in media thickness and wall to lumen ratio and by a significant increase in aortic nuclear density. Quinapril also limited vascular fibrosis development. At the cardiac level, quinapril reduced heart weight to body weight ratio and opposed myocardial hypertrophy and cardiac collagen synthesis. All these vascular and cardiac morphological changes were delayed (starting after 9-15 weeks of treatment) as compared to quinapril's hemodynamic effects. Finally, the drug's vascular and cardiac antihypertrophic properties persisted after treatment withdrawal. In conclusion, our data indicate that the early systemic and regional hemodynamic effects of quinapril initiate its antihypertensive action, but the drug-induced delayed and prolonged vascular morphological changes later take over and may be partly responsible for quinapril's residual blood pressure lowering effects after treatment withdrawal.

Animals↗
PubMed1991

Transcutaneous electrical nerve stimulation (TENS) in Raynaud's phenomenon.

Transcutaneous nerve stimulation (TENS) has been described as resulting in vasodilatation. The effect of 2 Hz TENS of the right hand during forty-five minutes on skin temperature and plethysmography of the third digit of both hands and feet and on transcutaneous oxygen tension (TcpO2) of the right hand was compared with that of a control study using indifferent stimulation of the iliopsoas region in 8 patients with primary Raynaud's phenomenon. After TENS a slight increase in skin temperature of both hands was found, while plethysmographic amplitude was increased in the contralateral hand only. No changes in TcpO2 occurred. The authors conclude that the observed small effects of TENS are of no clinical value in primary Raynaud's phenomenon.

Adult↗
PubMed1990

Prolonged blood pressure reduction by orally active renin inhibitor RO 42-5892 in essential hypertension.

OBJECTIVE: To investigate the effects of a novel specific renin inhibitor, RO 42-5892, with high affinity for human renin (Ki = 0.5 x 10(-9) mol/l), on plasma renin activity and angiotensin II concentration and on 24 hour ambulatory blood pressure in essential hypertension. DESIGN: Exploratory study in which active treatment was preceded by placebo. SETTING: Inpatient unit of teaching hospital. PATIENTS: Nine men with uncomplicated essential hypertension who had a normal sodium intake. INTERVENTIONS: Two single intravenous doses of RO 42-5892 (100 and 1,000 micrograms/kg in 10 minutes) given to six patients and one single oral dose (600 mg) given to the three others as well as to three of the patients who also received the two intravenous doses. RESULTS: With both intravenous and oral doses renin activity fell in 10 minutes to undetectably low values, while angiotensin II concentration fell overall by 80-90% with intravenous dosing and by 30-40% after the oral dose. Angiotensin II concentration was back to baseline four hours after the low and six hours after the high intravenous dose and remained low for at least eight hours after the oral dose. Blood pressure fell rapidly both after low and high intravenous doses and after the oral dose and remained low for hours. With the high intravenous dose the daytime (0900-2230), night time (2300-0600), and next morning (0630-0830) systolic blood pressures were significantly (p less than 0.05) lowered by 12.5 (95% confidence interval 5.6 to 19.7), 12.2 (5.4 to 19.3), and 10.7 (3.2 to 18.5) mm Hg respectively, and daytime diastolic pressure was lowered by 9.3 (2.2 to 16.8) mmHg. With the oral dose daytime, night time, and next morning systolic blood pressures were lowered by 10.3 (5.5 to 15.4), 10.5 (4.2 to 17.2), and 9.7 (4.0 to 15.6) mm Hg, and daytime and night time diastolic pressures were lowered by 5.8 (0.9 to 11.0) and 6.0 (0.3-12) mm Hg respectively. CONCLUSIONS: The effect of the inhibitor on blood pressure was maintained over a longer period than its effect on angiotensin II. RO 42-5892 is orally active and has a prolonged antihypertensive effect in patients who did not have sodium depletion. This prolonged effect seems to be independent, at least in part, of the suppression of circulating angiotensin II.

Administration, Oral↗
PubMed1990

Cardiovascular and biological effects of K+ channel openers, a class of drugs with vasorelaxant and cardioprotective properties.

Several new chemical entities (RP 52891, cromakalim and its derivatives) are potent and specific openers of vascular K+ channels. This mechanism is also shared, at least partially, by drugs such as minoxidil, diazoxide, pinacidil and nicorandil. The opening of plasmalemma K+ channels produces loss of cytosolic K+. This effect results in cellular hyperpolarization and functional vasorelaxation. In normotensive or hypertensive rats, K+ channel activators decrease aortic blood pressure (by producing a directly mediated fall in systemic vascular resistance) and reflexly increase heart rate. The former effect is not modified by specific blockers of classical vascular receptors but it is completely antagonized by the hypoglycemic sulphonylurea, glibenclamide, an established blocker of ATP-regulated K+ channels. K+ channel openers produce selective coronary vasodilatation and afford functional and biochemical protection to the ischemic myocardium. This salutary effect is mediated via cardiac K+ channel modulation and may result from an improved myocardial oxygen balance in the ischemic region. K+ channel openers increase plasma renin activity in animals as well as in man. However, only diazoxide, but not cromakalim or RP 52891, lowers plasma insulin concentration. The dose of glibenclamide entirely blocking the latter effect is over 50-fold smaller than that antagonizing the hypotensive and hyper-reninemic responses to diazoxide. In conclusion, K+ channel activators are potent vasorelaxant and cardioprotective agents possessing an original mechanism of action which is the opening of plasmalemma ATP-regulated K+ channels. Their clinical use as antihypertensive agents may be accompanied by undesirable effects (characteristic of peripheral vasodilators) which are likely to be attenuated or avoided by controlled release formulations. However, inasmuch as low doses of K+ channel openers may be sufficient to produce selective coronary artery dilatation and cardioprotection, these compounds could be of particular value in treating patients with coronary artery disease efficaciously and possibly without adverse cardiovascular effects.

Animals↗
PubMed1990

Systemic and regional haemodynamic interactions between K+ channel openers and the sympathetic nervous system in the pithed SHR.

1. The interactions between two K+ channel openers, cromakalim and SR 44866 (infused i.v. at equihypotensive doses), and the sympathetic nervous system at the systemic and regional (mesentery, kidney, hindlimb) vascular levels were investigated in the pithed spontaneously hypertensive rat (SHR) by use of the pulsed Doppler technique. 2. The two K+ channel openers did not affect postsynaptic alpha 1- but slightly reduced postsynaptic alpha 2-adrenoceptor mediated systemic pressor and regional vasoconstrictor responses. 3. Both drugs significantly decreased the systemic pressor and regional vasoconstrictor responses elicited by spinal cord stimulation. These sympathoinhibitory effects were not homogeneously distributed among the different vascular beds, the decreasing rank order being: mesentery greater than kidney greater than hindlimb. Simultaneously, the spinal cord stimulation-induced tachycardia remained unaffected. 4. After treatment with K+ channel openers, restoration of initial blood pressure and vascular tone values by infusion of prostaglandin F2 alpha (PGF2 alpha) and vasopressin respectively did not affect and abolished the sympathoinhibitory effects of cromakalim and SR 44866. 5. We conclude that in SHRs the two K+ channel openers that we investigated exert similar sympathohibitory effects which affect some vascular beds more than others. These effects are not dependent upon the arterial blood pressure level and are most likely prejunctionally located.

Animals↗
PubMed1989

Fatigue and heart disease. The association between 'vital exhaustion' and past, present and future coronary heart disease.

In order to study the association between vital exhaustion and different manifestations of coronary heart disease, a prospective study was conducted among 3877 males, aged 39-65. This group was studied during a mean period of 4.2 years. Vital exhaustion, a mental state characterized by unusual fatigue, a feeling of being dejected or defeated, and increased irritability, were assessed by means of the Maastricht Questionnaire. Subjects who scored in the upper third were labelled as exhausted and were compared with those who scored in the lower or middle third. The age-adjusted relative risk of angina pectoris at screening that was associated with vital exhaustion was 4.17 (p less than 0.01); that of unstable angina pectoris at screening was 17.21 (p less than 0.001). No association was observed between vital exhaustion and past myocardial infarction, except in the youngest age group (OR = 3.76; p = 0.05). Among the subjects free from coronary heart disease at screening, 54 cases of angina pectoris, 38 cases of non-fatal myocardial infarction, and 21 cases of fatal myocardial infarction were observed during follow-up. The age-adjusted relative risk of angina pectoris at follow-up was found to be 1.86 (p less than 0.03) and that of non-fatal myocardial infarction was found to be 2.28 (p less than 0.001). No association was found between vital exhaustion and fatal events.

Adult↗