Metabolic effects in rats drinking increasing concentrations of sea-water.
Research on laboratory rats confirmed that drinking sea-water when dehydrated, was not beneficial and caused impaired renal function. When the concentration of sea-water in the drinking water is gradually increased there is a gradual increase in water uptake and corresponding urine excretion. At 50% sea-water the maximum uptake and excretion is reached. Following this there is a decline in appetite, water uptake and urine secretion. When on 100% sea-water, the creatinine clearances were greater than on tap water, while urine/plasma osmolalities (U/P) averaged 7. The only higher U/P was found in animals drinking sea-water when dehydrated, i.e. a U/P of 11. The urea metabolism appears to be suited to either the need to conserve body water, up to 50% sea-water, or to guarantee an adequate urine production, from 50% sea-water to pure sea-water. It is suggested that when a man is stranded at sea it is not advisable to drink all the fresh water and then be compelled to drink sea-water when dehydrated. It is better to slowly increase the sea-water uptake. This will prolong the time before sea-water needs to be drunk and result in only minor metabolic changes. Return to fresh water will be followed by an immediate return to normal homeostasis.
D000818:Animals; D001066:Appetite; D001835:Body Weight; D003404:Creatinine / Q000378:metabolism; D004326:Drinking; D005243:Feces; D006400:Hematocrit; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012623:Seawater; D014508:Urea / Q000378:metabolism; D014556:Urine; D014881:Water Supply; D014882:Water-Electrolyte Balance
D014508:Urea; D003404:Creatinine