KOLANUT (KOLA-NITIDA) ENHANCES ANTIDIURETIC ACTIVITY IN YOUNG DEHYDRATED SUBJECTS

We have studied the influence of kolanut (approximately 0.50 g/kg body weight) on thirst and fluid intake, as well as urine output in young and elderly control and dehydrated healthy subjects in the North and S outh-West of Nigeria, Fluid intake was either ad libitum (water only) or a fixed load of approximately 17.5 mL/kg of either water or 0.9 % N aCl orally, Thirst rating and urine output were determined every 30 mi n for up to 120 min, The 12 h urine output in the northern part of the country was lower than that in the southern part, Dehydration reduced the 12 h urine output and increased thirst rating in both young and e lderly subjects, Much of the drinking associated with thirst took plac e within the first 30 min of provision of water, There is a significan t relationship between thirst rating and the amount of fluid intake du ring this period, Kolanut stimulates drinking and elevates thirst rati ng, However, when urine output was expressed as a percentage of the fl uid intake/load, kolanut significantly reduced the excretion of water in only the dehydrated subjects suggesting that kolanut may be potenti ating antidiuretic hormone activity in circulation, This was significa nt only in the young subjects, Since this response was blunted in norm al saline loaded subjects, the results further suggest that a change i n plasma osmolality (rather than volume) is the major determinant of p lasma antidiuretic activity affected by kolanut, It can be concluded t hat kolanut enhances plasma antidiuretic activity and this is related to a change in plasma osmolality and to the age of subjects.