ISSN:
1432-136X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Mechanisms inducing drinking after water deprivation, and mechanisms terminating drinking after rehydration, were investigated in the quail,Coturnix coturnix japonica. 1. Water intake was induced after 4 h of water deprivation, and the amount of water drunk increased in proportion to the period of water deprivation. Drinking occurred immediately after deprived birds were given access to water, and continued for periods proportional to the period of water deprivation. 2. Plasma angiotensin II concentration increased, as did plasma osmolality and Na+ concentration, and blood volume decreased after water deprivation. The increase in plasma angiotensin II concentration and decrease in blood volume occurred soon after the start of water deprivation, whereas plasma osmolality and Na+ concentration did not increase until at least 4 h after the start of water deprivation. 3. These results indicate that extracellular dehydration and angiotensin II are responsible for the significant drinking that follows 4 h of water deprivation, and that cellular dehydration is also involved in the stimulation of drinking that occurs after longer periods of water deprivation. 4. Plasma osmolality and Na+ concentration in birds deprived of water for 48 h quickly returned to normal levels after the birds were allowed access to water. Plasma angiotensin II levels and blood volume also approached the values measured prior to water deprivation. However, the rate and degree of restoration of normal values were reduced, and normal values were not restored even after 1.5 h of rehydration when drinking terminated. 5. The amount of water drunk over the course of 1.5 h by birds deprived of water for 48 h was much greater than the amount required to restore the changes in plasma osmolality and blood volume to normal, but neither excessive dilution of plasma nor abnormally high blood volumes were observed during drinking or 0.5 h after drinking terminated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00692559
