Biomedical subjects

W H Martin

Publications and source records attributed to W H Martin.

At least 73 records · Page 4Linked to original sources

PubMed1990

Correlation study of two-channel recordings of the brain stem auditory evoked potential.

Two-channel recordings of the brain stem auditory evoked potential (BAEP), for example, forehead to ipsilateral mastoid and forehead to contralateral mastoid, presumably provide "views" of the generators from different, nearly orthogonal, directions. The two channels thus are expected to register somewhat different waveforms, as revealed by past research. Still, the absolute latencies of the peaks are expected to be strongly correlated between channels. To test this notion, correlation analyses were made of the latencies of positive and negative peaks of normal-appearing BAEPs. The results demonstrated the expected high correlations for brain stem components but less tight coupling between peaks of waves of more peripheral origins. The possible influence of residual noise also was considered. Implications of the findings for clinical and multichannel recording applications are discussed.

Adult↗

PubMed1990

Interactions of the complex secretory vesicle binding protein chromobindin A with nucleotides.

Chromobindin A is a large, multisubunit protein that binds to chromaffin granule membranes in a Ca2+- and ATP-regulated manner. Ca2+ stimulates binding to the membrane, whereas ATP, in the the absence of Ca2+, is required for release of the protein from the membrane. We now report that spectral and HPLC data indicate that nucleotides are associated with the native chromobindin A complex and that the protein can bind two molecules of [3H]ATP in vitro. Chromobindin A also appears to be a novel nucleotide triphosphatase. ATPase activity was detected in fractions containing chromobindin A isolated by affinity chromatography, gel filtration, or ion exchange chromatography. Kinetic studies indicated that the Vmax is 44 nmol of Pi/mg/min and the Km is 0.115 mM, whereas the nonhydrolyzable ATP analog 5'-adenylylimidodiphosphate acts as a competitive inhibitor of this reaction with a Ki of 0.08 mM. The activity was found to be sensitive to protease treatment or to preincubation at 65 degrees C and was inhibited by Ca2+ or low pH. The ATPase activity was not inhibited by N-ethylmaleimide, N,N'-dicyclohexylcarbodiimide, vanadate, oligomycin, or azide.

Adenosine Triphosphatases↗

PubMed1990

Autoradiographic delineation of skeletal muscle alpha 1-adrenergic receptor distribution.

We used light microscopic autoradiography to quantify the distribution of alpha 1-adrenergic receptors in vessels and muscle fibers of slow-twitch (type I), fast-twitch (types IIa and IIb), and mixed fiber muscles of the rat hindquarter. Frozen cross sections of soleus, vastus lateralis, and gastrocnemius muscles were incubated under equilibrium binding conditions with 10-200 pM [3H]prazosin with or without 10(-5) M phentolamine. Because of the low concentration of bound radioligand, specific binding could not be detected with scintillation spectrometry in whole tissue sections scraped from slides. However, quantitative autoradiographic analysis after extended intervals of emulsion exposure revealed a low but significant level of specific binding in muscle fibers. No difference in alpha 1-receptor density was observed among types I, IIa, and IIb fibers. Small blood vessels had a much greater alpha 1-receptor density than muscle fibers. Resistance arterioles (20-100 microns diam) and small arteries (100-500 microns diam) contained 5.8 +/- 0.9 and 31.6 +/- 7.6 (+/- SE) times more binding sites per unit section area, respectively, than did surrounding muscle fibers (both P less than 0.001). Ratios of specific grain densities in fibers and blood vessels did not vary with radioligand concentration, indicating that observed grain densities reflected differences in receptor concentration rather than radioligand affinity by fiber and vessel receptors. The densities of vascular alpha 1-receptors did not vary in slow- and fast-twitch muscles, but resistance arterioles were six and eight times more numerous in soleus than in gastrocnemius and vastus muscles, respectively (both P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗

PubMed1990

Decline in VO2max with aging in master athletes and sedentary men.

Fifteen well-trained master endurance athletes [62.0 +/- 2.3 (SE) yr] and 14 sedentary control subjects (61.4 +/- 1.4 yr) were reevaluated after an average follow-up period of approximately 8 yr to obtain information regarding the effects of physical activity on the age-related decline in maximal O2 uptake capacity (VO2max). The master athletes had been training for 10.2 +/- 2.9 yr before initial testing and continued to train during the follow-up period. The sedentary subjects' VO2max declined by an average of 3.3 ml.kg-1.min-1 (33.9 +/- 1.7 vs. 30.6 +/- 1.6, P less than 0.001) over the course of the study, a decline of 12% per decade. In these subjects maximal heart rate declined 8 beats/min (171 vs. 163) and maximal O2 pulse decreased from 0.20 to 0.18 ml.kg-1.beat (P less than 0.05). The master athletes' VO2 max decreased by an average of 2.2 ml.kg-1.min-1 (54.0 +/- 1.7 vs. 51.8 +/- 1.8, P less than 0.05), a 5.5% decline per decade. The master athletes' maximal heart rate was unchanged (171 +/- 3 beats/min) and their maximal O2 pulse decreased from 0.32 to 0.30 ml.kg-1.beat (P less than 0.05). These findings provide evidence that the age-related decrease in VO2max of master athletes who continue to engage in regular vigorous endurance exercise training is approximately one-half the rate of decline seen in age-matched sedentary subjects. Furthermore our results suggest that endurance exercise training may reduce the rate of decline in maximal heart rate that typically occurs as an individual ages.

Aged↗

PubMed1990

Exercise training enhances leg vasodilatory capacity of 65-yr-old men and women.

To determine whether extremity vasodilatory capacity may be augmented in older persons by endurance exercise training, lower leg blood flow and conductance were characterized plethysmographically at rest and during maximal hyperemia in 9 men and 10 women aged 64 +/- 3 (SD) yr before and after 31 +/- 6 wk of walking and jogging at 70-90% of maximal oxygen uptake for 45 min 3-5 days/wk. Maximal oxygen uptake expressed as milliliters per kilogram per minute improved 25% in men and 21% in women (P less than 0.01). Maximal leg blood flow and conductance increased in all nine men by an average of 39 +/- 33 (P less than 0.001) and 42 +/- 44% (P less than 0.004), respectively. Results were more variable in women and achieved unequivocal statistical significance only for maximal blood flow (+33 +/- 54% for blood flow and +29 +/- 55% for conductance; P less than 0.02 and P = 0.05, respectively). Body weight and skinfold adiposity declined in both sexes (P less than 0.05). Enhancement of vasodilatory capacity was related to weight loss in men and adipose tissue loss in women (r = 0.61 and 0.51, respectively; P less than 0.05). There were no significant changes in exercise capacity, body weight, or maximal blood flow in four male and three female controls aged 66 +/- 4 yr. Thus adaptability of the lower limb circulation to endurance exercise training is retained to at least age 65 yr.

Aged↗

PubMed1990

A comparison of rapid enzyme immunoassay tests for the detection of Chlamydia trachomatis cervical infections.

Two rapid enzyme immunoassay test kits were compared with culture for the detection of Chlamydia trachomatis endocervical infections. Endocervical samples for C trachomatis culture and the two enzyme immunoassay tests were evaluated from 502 county health department and Planned Parenthood patients. The prevalence of infection in this population was 12%. Sensitivity and specificity of the Abbott TestPack Chlamydia were 51.7% and 99.5%, respectively, and of the Kodak Surecell Chlamydia were 76.7% and 98.6%, respectively. The positive and negative predictive values for TestPack were 93.9% and 93.8%, and for Surecell were 88.5% and 96.9%, respectively. Additionally, an in vitro investigation was used to evaluate whether typical office staff (physicians, nurses, medical technicians, receptionists, and radiology technicians) were able to perform competently the tests in each kit. Office personnel tested 12 dilutions of a C trachomatis stock sample or negative control sample as unknowns for each kit in the in vitro investigation. There were no differences among office staff in performance when compared for each test kit. Selective use of these enzyme immunoassay tests for high-risk patients in a family practice population that has a high prevalence of patients with C trachomatis infection may be helpful when rapid test results are required and cultures are not feasible. After appropriate training, most physician office personnel were equally able to perform the enzyme immunoassay tests evaluated.

Adult↗

PubMed1989

Chromobindin A, a Ca2+- and ATP-dependent chromaffin granule-binding protein, is found in a variety of tissues and in yeast.

Chromobindin A is a ring shaped, multisubunit protein which exhibits Ca2+ and ATP-dependent binding to chromaffin granule membranes. Here we report biochemical and immunochemical evidence for the presence of chromobindin A in a surprisingly broad range of tissues: The protein is abundant in bovine skeletal muscle, pancreas, adrenal cortex and in brain gray and white matter; it is present in low quantities in the parotid, intestine and spleen and is undetectable in lung. Interestingly, chromobindin A was also detected in extracts of yeast. Electron micrographs of the yeast protein reveal a morphology virtually identical to the mammalian protein. These results suggest that chromobindin A is an important protein in a wide variety of cell types and that it has been highly conserved through evolution.

Animals↗

PubMed1989

Effect of exercise training in 60- to 69-year-old persons with essential hypertension.

This study sought to determine whether 9 months of low- or moderate-intensity exercise training could decrease blood pressure (BP) in hypertensive men and women (mean age 64 +/- 3 years). Patients underwent weekly BP evaluations for 1 month to ensure that they had persistently elevated BP and then completed a maximal treadmill exercise test to exclude those with overt coronary artery disease. The low- and moderate-intensity groups trained at 53 and 73% of maximal oxygen consumption (VO2 max), respectively; however, total caloric expenditure per week was similar in both groups. VO2 max did not increase in the low-intensity group with training, but increased 28% in the moderate-intensity group. Diastolic BP decreased 11 to 12 mm Hg in both training groups. Systolic BP decreased 20 mm Hg in the low-intensity group with training, which was significantly greater than the change in the control and the moderate-intensity groups. Although systolic BP decreased 8 mm Hg in the moderate-intensity training group, this reduction was not significant. Training resulted in a somewhat lower cardiac output at rest in the low-intensity group, whereas total peripheral resistance decreased slightly in the moderate-intensity training group. Plasma and blood volumes, plasma renin levels and urinary sodium excretion did not change in either group with training. Both groups manifested lower plasma norepinephrine levels after training during standing rest, but not while supine. Thus, low-intensity training may lower BP as much or more than moderate-intensity training in older persons with essential hypertension, but the underlying mechanisms are unclear.

Aged↗

PubMed1989

Effects of active muscle mass size on cardiopulmonary responses to exercise in congestive heart failure.

Previous studies from this laboratory demonstrated that in healthy young men, cardiac output is closely coupled to oxygen uptake during dynamic exercise, regardless of its mode or relative intensity, whereas other physiologic responses such as heart rate, blood pressure and ventilation are inversely related to the size of the active muscle mass when expressed as functions of oxygen uptake. The purpose of the current investigation was to determine whether congestive heart failure alters the pattern of physiologic responses to various modes of arm and leg exercise in proportion to the size of the active muscle mass. Cardiopulmonary responses to four modes of dynamic work (one arm curl, one arm cycle ergometry, one leg cycle ergometry and two leg cycle ergometry) were characterized in terms of absolute and relative intensities (oxygen uptake and mode-specific percent of peak oxygen uptake, respectively) in middle-aged men with congestive heart failure and control groups of healthy subjects and patients after myocardial infarction without heart failure. Peak oxygen uptake was reduced to the greatest extent in patients with heart failure for large muscle mass work (-13% for curl, -32% for one arm and one leg cycle ergometry and -37% for two leg cycle ergometry; p less than 0.05 versus the normal group for the three modes of ergometry). This finding was paralleled by a markedly blunted slope for the cardiac output-oxygen uptake relation for leg but not arm exercise that was only partially compensated for by a widened arteriovenous oxygen difference. Blood pressure expressed as a function of oxygen uptake remained inversely related to active muscle mass size in all groups of subjects despite attenuation of systolic pressure for heavy large muscle mass effort in the group with heart failure. Pulmonary ventilation at a given metabolic rate was not influenced by active muscle mass size. Thus, saturation of capacity for systemic oxygen transport occurs in conjunction with blunted cardiac output reserve in patients with heart failure during exercise involving a smaller muscle mass than in healthy subjects. The basic inverse relation between size of the active muscle mass and blood pressure at a given metabolic rate is not altered by aging or reduced cardiac reserve. The muscle mass effect on ventilation seen in young healthy subjects disappears with aging.

Blood Pressure↗

PubMed1989

Effects of fiber type and training on beta-adrenoceptor density in human skeletal muscle.

The density and distribution of beta-adrenergic receptors in type I and II fibers of human gastrocnemius and quadriceps muscles were characterized in ten healthy sedentary subjects and in a subgroup of six subjects before and after 12 wk of endurance exercise training. Total tissue content of beta-receptors was measured in frozen sections of skeletal muscle biopsies incubated with 125I-labeled cyanopindolol in the presence and absence of 10(-5) M L-propranolol. The relative beta-receptor densities of type I and II fibers were delineated autoradiographically. Muscle fiber types were identified in adjacent serial sections by histochemical staining of myofibrillar adenosine-triphosphatase (ATPase) activity. Type I fibers had a threefold greater beta-receptor density than type II fibers of the same muscle [P less than 0.001; type I-to-type II fiber ratio of beta-receptor density was 3.06 +/- 0.43 (SD)]. Exercise training elicited a change in muscle fiber subtype composition (+34% type IIa and -42% type IIb; P less than 0.05 and P = 0.066, respectively), a 40% increase in citrate synthase activity of skeletal muscle (P = 0.01), and a 23% rise in peak oxygen uptake (P less than 0.001). However, no change in total tissue content of beta-receptors was observed after exercise training, even when receptor density was adjusted for preconditioning fiber type composition. Thus beta-receptor density of type I fibers of human skeletal muscle is threefold greater than that of type II fibers. Enhanced capacity for aerobic metabolism after endurance exercise training is not associated with upregulation of total beta-receptor density.

Adult↗

PubMed1989

Beta-adrenergic receptor distribution among muscle fiber types and resistance arterioles of white, red, and intermediate skeletal muscle.

The pathophysiological effects of congestive heart failure and physiological effects of exercise training on skeletal muscle may be mediated in part by modulation of beta-adrenergic receptor density. To shed light on the physiological role of skeletal muscle beta-receptors, their density and distribution were characterized in muscle fibers and resistance arterioles of whole tissue slices of three rat hindquarter muscles differing markedly in fiber type composition and capacities for oxidative metabolism and vasodilatation. Binding isotherms and quantitative light microscopic autoradiographic localization of receptors were performed by incubating tissue slices in selected concentrations of [125I]cyanopindolol with and without 10(-5) M l-propranolol. Muscle fiber types were delineated in adjacent sections by histochemical staining of myofibrillar ATPase activity at pH 4.5-4.55. The total tissue content of receptors (Bmax) was nearly threefold greater in the soleus, a muscle consisting almost entirely of slow-twitch (type I) fibers than in superficial white vastus lateralis, a muscle composed of greater than 95% fast-twitch (type IIb) fibers. Bmax was intermediate in gastrocnemius, a mixed fiber muscle (all differences p less than 0.01). Receptor affinity for radioligand was higher in the white vastus than in the mixed fiber and slow-twitch muscles (Kd = 3.5 +/- 0.4 pM for white vastus versus 6.8 +/- 0.8 and 6.4 +/- 1.1 pM in gastrocnemius and soleus, respectively; both p less than 0.01 versus white vastus). Disparities in Bmax among muscles were due entirely to differences in receptor densities of skeletal muscle cells as shown autoradiographically. Furthermore, variations in Bmax of the three skeletal muscles were directly related to percentage of type I fibers (r = 0.99; p less than 0.001), which had a beta-receptor density that was approximately 4.5-fold greater than in superficially located type IIb fibers, 3.2-fold greater than in intermediate depth type IIb fibers, and 2.0-fold greater than in type IIa fibers. In contrast, grain densities of resistance arterioles were similar regardless of surrounding skeletal muscle fiber type composition. However, resistance arterioles were 2.5- and 6.1-fold more numerous in the slow-twitch soleus than in the gastrocnemius and superficial white vastus, respectively (all differences p less than 0.01). We conclude that beta-receptor density of rat hindquarter skeletal muscles is directly proportional to percentage of slow-twitch fibers, while receptor affinity for antagonist is higher in fast-twitch than in slow-twitch or mixed fiber muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗

PubMed1988

Effect of 6 d of exercise training on responses to maximal and sub-maximal exercise in middle-aged men.

Nine sedentary men (53 +/- 3 yr) were studied before and after 6 d of endurance exercise training to determine the effects on maximal oxygen uptake (VO2max), and on the heart rate, blood pressure, and metabolic responses to a standard bout of steady-state sub-maximal exercise. The subjects exercised approximately 1 h.d-1 at about 68% of VO2max. The 6-d protocol elicited no improvement in VO2max (2.50 +/- 0.14 before vs 2.58 +/- 0.15 l.min-1 after training). Heart rates were significantly lower by 5 to 8 b.min-1, systolic blood pressures were reduced by 16 to 19 mm Hg, and blood lactate concentrations were 25 to 35% less at the same exercise intensities (60, 70, and 80% of VO2max) after 6 d of exercise. Rate pressure product was about 15% lower at the same exercise intensity after 6 d of training (P less than 0.05). The respiratory exchange ratio during submaximal exercise was 0.02 to 0.04 units lower (P less than 0.05; P less than 0.01) after 6 d of exercise, indicating a shift in substrate utilization favoring fat oxidation. These findings suggest that short-term endurance training can induce heart rate, blood pressure, and metabolic adaptations to sub-maximal exercise before there is a significant increase in VO2max in sedentary, middle-aged men who are capable of vigorous exercise.

Blood Pressure↗

PubMed1987

Chromobindin A. A Ca2+ and ATP regulated chromaffin granule binding protein.

A variety of studies have shown that about 20 proteins can be isolated from bovine adrenal medullary cytosol by virtue of their ability to bind to chromaffin granule membranes in the presence of Ca2+. In the present study we have examined the properties of a group of seven of these proteins. This group of proteins binds to granule membranes in the presence of Ca2+, however, the proteins are not released from the membrane by the removal of Ca2+ unless ATP is present. The proteins range from 53 to 59 kDa and they form a multisubunit complex of about 800 kDa. This complex, which we have named chromobindin A, has 13 subunits joined together in a ring, 175 A in diameter and 115 A in height. The binding of chromobindin A to membranes is stimulated by Ca2+, Sr2+, and Ba2+. The release is stimulated by a variety of nucleotides, including the nonhydrolyzable nucleotide analog adenyl-5'-yl imidodiphosphate. At present the function of chromobindin A in vivo is not clear, although the observation that Ca2+ stimulates chromobindin A binding together with observations that imply that chromobindin A binds to a protease-sensitive receptor on the granule membrane suggest that the complex is involved in exocytosis and that it may be partially responsible for the ATP dependence of this process.

Adenosine Triphosphate↗

PubMed1987

Identification of chromaffin granule-binding proteins. Relationship of the chromobindins to calelectrin, synhibin, and the tyrosine kinase substrates p35 and p36.

At least 23 soluble proteins (chromobindins) bind to chromaffin granule membranes in the presence of Ca2+. In order to further the identification of the chromobindins and to determine the roles they may play in exocytosis or other aspects of chromaffin cell biology, several of these proteins were compared to other known membrane-binding proteins. Chromobindin 4 was identified as a 32-kDa protein called calelectrin or endonexin. Immunologically related proteins were detected in bovine brain and human platelets. Chromobindin 20 was identified as a 67-kDa variant of calelectrin and was found to have the activities of the synexin inhibitory protein, synhibin. Chromobindin 8 was identified as p36, a substrate for the tyrosine-specific kinase, pp60v-src. Chromobindin 8 was also demonstrated to undergo phosphorylation predominantly on alkali-sensitive sites during stimulation of the chromaffin cell with 20 microM nicotine. Chromobindin 6 was identified as p35, a substrate for the tyrosine kinase activity associated with the epidermal growth factor receptor. Chromobindin 9, which is known to be a substrate for protein kinase C (Ca2+/phospholipid-dependent enzyme), was found to be immunologically related to p35 and may be a precursor of chromobindin 6. The identification of these proteins from the chromaffin system may be useful in the characterization of similar, complex groups of membrane-binding proteins that have been observed in other systems.

Amino Acids↗

PubMed1987

Maximal vascular leg conductance in trained and untrained men.

Lower leg blood flow and vascular conductance were studied and related to maximal oxygen uptake in 15 sedentary men (28.5 +/- 1.2 yr, mean +/- SE) and 11 endurance-trained men (30.5 +/- 2.0 yr). Blood flows were obtained at rest and during reactive hyperemia produced by ischemic exercise to fatigue. Vascular conductance was computed from blood flow measured by venous occlusion plethysmography, and mean arterial blood pressure was determined by auscultation of the brachial artery. Resting blood flow and mean arterial pressure were similar in both groups (combined mean, 3.0 ml X min-1 X 100 ml-1 and 88.2 mmHg). After ischemic exercise, blood flows were 29- and 19-fold higher (P less than 0.001) than rest in trained (83.3 +/- 3.8 ml X min-1 X 100 ml-1) and sedentary subjects (61.5 +/- 2.3 ml X min-1 X 100 ml-1), respectively. Blood pressure and heart rate were only slightly elevated in both groups. Maximal vascular conductance was significantly higher (P less than 0.001) in the trained compared with the sedentary subjects. The correlation coefficients for maximal oxygen uptake vs. vascular conductance were 0.81 (trained) and 0.45 (sedentary). These data suggest that physical training increases the capacity for vasodilation in active limbs and also enables the trained individual to utilize a larger fraction of maximal vascular conductance than the sedentary subject.

Adult↗

PubMed1987

Blood pressure and hemodynamic responses after exercise in older hypertensives.

Recently, systolic and diastolic blood pressure have been reported to be significantly lower for several hours after exercise than when measured at rest before exercise in individuals with essential hypertension. We sought to determine the hemodynamic mechanism underlying this reduction in blood pressure. Twenty-four men and women 60-69 yr of age with persistent essential hypertension completed one of the following protocols: exercise at 50% of maximum O2 consumption (VO2 max) followed by 1 h of recovery, exercise at 70% of VO2 max followed by 3 h of recovery, or a 4-h control study. Systolic pressure was significantly lower during recovery after both intensities of exercise, but diastolic pressure was unchanged. The lower blood pressure was primarily due to a reduction in cardiac output, since total peripheral resistance was increased throughout both recovery periods. Cardiac output was reduced in recovery because of a reduction in stroke volume. Heart rate was above, or no different from, that at rest before exercise. Changes in plasma volume could not entirely account for the reduction in stroke volume. Therefore, other mechanisms altering venous return and/or myocardial contractility appear to be responsible for the reduction in systolic blood pressure evident after a single bout of submaximal exercise in individuals with essential hypertension.

Aged↗

PubMed1987

Cardiovascular adaptations to intense swim training in sedentary middle-aged men and women.

Central and peripheral cardiovascular adaptations to 12 weeks of intense swim training were characterized in 12 previously sedentary middle-aged men and women. Peak oxygen uptake (VO2) during upright bicycle exercise improved from 29.2 +/- 5.6 to 34.7 +/- 6.7 ml/kg/min (mean +/- SD, p less than .01) because of similar increases in peak cardiac output (CO) and calculated arteriovenous oxygen difference (both p = .02). Peak supine VO2 was 10% higher after training (p less than .005) solely because of enhanced CO (p = .005). Peak heart rate decreased in both postures; therefore stroke volume at peak exercise was greater by 10% and 18% in the upright and supine postures, respectively (p = .05 and p = .005). There was an identical 18% rise (p = .01) in peak supine left ventricular end-diastolic volume index by radionuclide ventriculography but no change in left ventricular ejection fraction or end-systolic volume index (ESVI). Peak systolic blood pressure (SBP) was unchanged in the upright posture but was 8% higher (p = .002) during recumbency despite a similar total peripheral resistance and SBP/ESVI ratio. Maximal calf conductance (Gmax), assessed separately by venous occlusion plethysmography after local ischemic exercise to fatigue, was augmented 20% (p less than .02) by training, resulting in an 18% greater hyperemic blood flow (p = .05). Peak VO2, CO, and Gmax were unchanged in five nonexercising control subjects. We conclude that in middle-aged humans, intense swim training for 12 weeks produces adaptations that include a greater capacity for vasodilatation in skeletal muscle and an enhanced cardiac pump capacity.

Adaptation, Physiological↗

PubMed1987

Reversal of exertional hypotension by prolonged exercise training in selected patients with ischemic heart disease.

The effect of prolonged intense endurance exercise training on exertional hypotension was investigated in 16 patients with coronary artery disease who had a 10 mm Hg or greater fall in systolic blood pressure (SBP) during progressive exercise testing. Training consisted of walking, running, or cycling at 50% to 60% of peak oxygen uptake (peak VO2) for 30 min 3 days per week for an initial 3 months and was followed by an additional 9 months of similar exercise performed at 70% to 90% of peak VO2 for 50 to 60 min 5 days per week. The 1 year program resulted in a 41% increase in peak VO2 and lower heart rate and blood pressure responses to submaximal work. Before conditioning, SBP attained a maximal value of 162 +/- 5 mm Hg but fell 21 +/- 3 mm Hg, to 141 +/- 7 mm Hg, at peak effort (p less than .01). After training, maximal SBP was achieved at a faster heart rate (157 +/- 5 vs 132 +/- 6 beats/min; p less than .001) and was 7.4% higher (174 +/- 6 vs 162 +/- 5 mm Hg; p less than .005), while SBP at peak exercise had increased by 21% (171 +/- 6 vs 141 +/- 7 mm Hg; p less than .001) and ST segment depression was slightly reduced. Left ventricular ejection fraction (LVEF) before training declined from 56 +/- 4% at rest to 52 +/- 3% at peak exercise (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗