MECHANISMS OF RENAL TUBULAR DEFECTS IN OLD AGE

The mechanisms of renal tubular dysfunction in old age have been examined in twenty-eight clinically healthy elderly subjects without infection, and in fourteen subjects of similar age with laboratory evidence of intrarenal infection. The data were compared with those from thirteen clinically healthy young subjects. Studied were: proximal tubular (Tm(PAH)) and distal tubular (CH2O) activity, [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments

DISTRIBUTION OF WATER LOSSES AMONG FLUID COMPARTMENTS OF TISSUES UNDER THERMAL DEHYDRATION IN THE RAT

Dehydration amounting to about 10% of body weight was induced in adult male rats by exposure to a hot, dry environment (D.B.T., 36 degrees C; R.H., 20%) over 6 to 8 hr. The volumes of total water (TW), extracellular fluid (ECF), and plasma (PV) were determined both on individual tissues and on the whole body [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Environmental conditions, Scientific papers|0 Comments

EFFECTS OF DEHYDRATION ON GASTRIC EMPTYING AND GASTROINTESTINAL DISTRESS WHILE RUNNING

Gastrointestinal distress is commonly reported by athletes after ingestion of a beverage. We speculate that ingestion may be occurring after dehydration has taken place. The high prevalence of GI disorders in marathon runners who have lost greater than or equal to 4% body weight supports this theory. To test this theory, the effects of dehydration, [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments

THE RESPONSE OF ARGININE VASOPRESSIN TO INTRAVENOUS ETHANOL AND HYPERTONIC SALINE IN MAN: THE IMPACT OF AGING

The effect of age on the hypothalamic-hypophyseal-renal axis in normal man was determined by assaying plasma arginine vasopressin (AVP) responses to inhibitory and to secretory stimuli. Nine young (21-49 years) and 13 old (54-92 years) subjects received IV ethanol (375 mg/m2 per min). AVP levels fell progressively during the infusion in the young group, but [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments

EFFECTS OF EXERCISE ON FLUID EXCHANGE AND BODY COMPOSITION IN MAN DURING 14-DAY BED REST

To determine the cause of the body weight loss during bed rest (BR), fluid balance and anthropometric measurements were taken from seven men (19-21 yr) during three 2-wk BR periods which were separated by 3-wk ambulatory recovery periods. Caloric intake was 3,073 +/- 155 (SD) kcal/day. During two of the three BR periods they performed [...]

PHYSIOLOGICAL CONSEQUENCES OF HYPOHYDRATION: EXERCISE PERFORMANCE AND THERMOREGULATION

During exercise in the heat, sweat output often exceeds water intake, which results in a body water deficit or hypohydration. This water deficit occurs from both the intracellular and extracellular fluid compartments, and causes a hypertonic-hypovolemia of the blood. Aerobic exercise tasks are likely to be adversely affected by hypohydration; and the warmer the environment [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Exercise and sport, Scientific papers|0 Comments