ABSTRACT
Nine normal men (mean age 27.6 yr) were exposed to continuous lower-body suction pressure (LBSP) of -20 to -50 mmHg (for 5 min at each level) on four different occasions after having consumed a single oral therapeutic dose of either diltiazem, nifedipine, verapamil, or a placebo, randomly, in a single blind manner. The suction was applied at 12.30 pm in all experiments, while the medications were administered in such a manner so that their expected peak plasma levels would have been achieved at the time of suction application. The cardiovascular reflex effects commenced at a pressure of -30 mmHg, and peaked at -50 mmHg. The increases in the heart rate for all treatments at -50 mmHg was statistically similar (about 16-20 beats/min). The systolic BP fell by about 9 mmHg for the placebo experiments, and this change was not different from the changes produced by the 3 Calcium channel blocker treatments. The diastolic BP increase was about 3 mmHg. The Cardiac index did not vary significantly. Our results suggest that the commonly used Ca++ channel blockers do not adversely affect orthostatic tolerance.
Subject(s)
Adult , Analysis of Variance , Blood Pressure/drug effects , Calcium Channel Blockers/pharmacology , Cardiovascular Physiological Phenomena , Cardiovascular System/drug effects , Electrocardiography , Heart Rate/drug effects , Humans , Lower Body Negative Pressure , Male , Physical Stimulation , Reflex/drug effects , Single-Blind Method , Stroke Volume/drug effectsABSTRACT
Peak expiratory flow rates were measured in 124 normal elderly men (55-85 yr) using the Wright's peak flow meter. In the less than 60 yrs age group (n = 32; mean age 57.7 yr) the PEFR was 431 +/- 13 lpm, while for the group greater than 60 yr (mean age 69.0 +/- 6.0; n = 92), the PEFR value was 373 +/- 11 1pm. These values are similar to those reported in other Indian studies, suggesting that the ethnic variations amongst Indian subjects do not affect the PEFR. However, the reported values are lower than those observed in Europeans, but greater than those of Chinese. The PEFR regressed at a rate of 4.47 1pm/year increase in age, but is positively correlated to the subjects' height (cm), and their FVC and FEVI. The smokers had a significantly higher PEFR as compared with the non-smokers. This finding was contrary to what was expected.