IMPAIRED OSMOSTIMULATION OF WATER INGESTION DELAYS RECOVERY FROM HYPEROSMOLARITY IN NORMAL ELDERLY
No abstract available.
HYPOHYDRATION DURING EXERCISE IN CHILDREN: EFFECT ON THIRST, DRINKING PREFERENCES, AND REHYDRATION
This study examined changes in children's thirst and drink preferences during exercise-induced hypohydration and their spontaneous rehydration during a 30-min recovery. Twenty-four 9- to 13-year-old children (14 females, 10 males) participated in four intermittent 90-min cycling sessions in the heat (35 degrees C, 20% relative humidity); the sessions differed in the drinks the children were [...]
THIRST
The homeostasis of body fluid traditionally is viewed as involving the regulation of its osmolality and of blood volume. However, the control of thirst is more complex than can be described in a two-factor model, and consideration of plasma sodium concentration and of arterial blood pressure also must be included in the discussion. This review [...]
ALTERATION OF ENDOTOXIN FEVER AND RELEASE OF ARGININE VASOPRESSIN BY DEHYDRATION IN THE GUINEA PIG
Arginine vasopressin (AVP), synthesized in hypothalamic neurons, is transported in axons either to the pituitary for release into the circulation or to different brain areas. In our previous experiments we documented central antipyretic AVP pathways from the hypothalamus to the ventrolateral septal area in the limbic system. In the present study we investigated if osmotic [...]
CHANGES IN TOTAL BODY WATER DURING ADOLESCENT GROWTH
Total body water was determined on 59 boys and 59 girls and on 40 boys and 45 girls attending junior and senior high schools, respectively. The volunteers were studied for three years. They were given D2O (99.8%) orally, and urine samples were used for determination of the ratio of heavy hydrogen to normal hydrogen by [...]
EFFECTS OF WATER TEMPERATURE AND FLAVORING ON VOLUNTARY DEHYDRATION IN MAN
Effects of water temperature and flavoring on fluid consumption and body weight losses were studied in fourteen unacclimatized men (21-33 years) during 6 hr of treadmill exercise (4.8 km.hr-1, 5% grade for 30 min.hr-1) in a hot environment. Subjects consumed each of four beverages (15 degrees C water, 40 degrees C water, 15 degrees C [...]
THE INFLUENCE OF AGE ON THE RENAL RESPONSE TO WATER DEPRIVATION IN MAN
Alterations in urine concentrating ability with age were examined in 98 active community-dwelling volunteers (aged 20-79 years) who were free from evidence of diseases known to adversely affect renal function. There was a significant decrease in urine osmolality reached after 12 h dehydration with advancing age, which could not be correlated with the age-related decline [...]
VOLUNTARY HYPOHYDRATION IN 10- TO 12-YEAR-OLD BOYS
This study was performed to determine whether a) children voluntarily dehydrate while exercising in hot climate; b) such dehydration affects their well-being and thermoregulation. Eleven 10p to 12-yr old, partially acclimatized boys underwent two work-in-the-heat protocols (cycle rides, 45% aerobic capacity at 39 degrees C, 45% rh). During one session they drank only voluntarily when [...]
VALIDATION OF THE DEUTERIUM DILUTION TECHNIQUE FOR THE MEASUREMENT OF FLUID INTAKE IN INFANTS
The validity of the deuterium dilution technique as a method of measuring fluid intake was investigated by comparing values obtained with this technique and direct measurements of milk intake in 10 exclusively bottle-fed infants recovering from protein-energy malnutrition. Values for total body water were derived from body weight and length using Friis-Hansen's formula. During a [...]
AGE-RELATED FAILURE OF VOLUME-PRESSURE-MEDIATED VASOPRESSIN RELEASE
Osmoreceptor sensitivity, as estimated by the plasma vasopressin (AVP) response to hypertonic saline infusion, increases with age. We studied volume-pressure sensitivity, as estimated by the plasma AVP response to orthostasis, in healthy young (19-31 yr old; n = 12) and old (62-80 yr old; n = 15) subjects. After remaining recumbent overnight (minimum of 8 [...]