Roger Wangler

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If adenosine is the major factor responsible for myocardial metabolic vasodilation, its release should be sustained as long as oxygen consumption and coronary flow are augmented. To see if adenosine meets this criterion, we examined the time course of its release during norepinephrine infusion in isolated, non-working guinea pig hearts (n = 8). During an(More)
We used the multiple-indicator-dilution technique to observe the capillary transport of adenosine in isolated Krebs-Henseleit-perfused guinea pig hearts. Tracer concentrations of radiolabeled albumin, sucrose, and adenosine were injected into the coronary inflow; outflow samples were collected for 10-25 s and analyzed by high-performance liquid(More)
We tested the hypothesis that capillary exchange of adenosine is influenced by the ability of endothelial cells (ECs) to take up adenosine. Triple-indicator diffusion experiments were performed by injecting [14C]adenosine, [3H]9-beta-D-arabinofuranosylhypoxanthine ( [3H]araH), and radioiodinated serum albumin (RISA) into the arterial perfusate of isolated(More)
Morphological studies have demonstrated an age-related decrease in capillary density and capillary surface area in the developing heart. However, the consequences of these changes on myocardial perfusion are not known. We tested the hypothesis that the decreased capillary density is associated with a reduction in coronary blood flow reserve. To test this(More)
We examined anatomical and physiological responses of the left coronary vascular system to thyroxine-induced myocardial hypertrophy. Wistar-Kyoto rats (1 and 5 months old) were administered thyroxine (0.25 mg/kg per day) or the saline vehicle (sham-treated controls) for 2 months. At the ages of 3 and 7 months, each group of animals was used for one of three(More)
Gastric bypass as a 90 per cent gastric exclusion operation was used in 393 patients with massive obesity to limit food intake. Stomal ulcer has occurred in 1.8 per cent of such patients or one ulcer per 140 man years of observation. The studies of indwelling fundic pH and of gastric acid secretion from the excluded stomach indicate that acid secretion is(More)
We have previously shown that maturation is associated with decreased maximum coronary flow (CF) elicited pharmacologically or by transient coronary occlusion (Toma, B.S., R.D. Wangler, D.F. DeWitt, and H.V. Sparks. Circ Res. 57: 538-544, 1985). The present study examines the influence of maturation on CF and adenosine release (RADO) during increased(More)
The felge, or undersomersault, on parallel bars has become an important skill in men's artistic gymnastics as it forms the basis of many complex variations. To receive no deductions from the judges, the felge must be performed without demonstrating the use of strength to achieve the final handstand position. Two male gymnasts each performed nine trials of(More)
Myocardial ischemia increases the release of adenosine (RADO), inosine (RINO), and norepinephrine; however, it is not known whether norepinephrine contributes to nucleoside production via the beta-adrenergic receptor. We used a Langendorff preparation (guinea pig) to study the time course of RADO and RINO during myocardial hypoperfusion (MH) produced by(More)
d-Propranolol eliminates the increased adenine nucleoside release from hypoperfused hearts [R. D. Wangler, D. F. DeWitt, and H. V. Sparks, Am. J. Physiol. 247 (Heart Circ. Physiol. 16): H330-H336, 1984]. To determine whether d-propranolol reduces adenosine formation or adenosine release into the vascular compartment, we measured myocardial tissue adenosine(More)