Abstract
1. During 24 hr water deprivation, the pregnant and lactating rats lost more weight than the non-mated animals. The increase in haematocrit was considerably greater in the lactating animals although plasma osmolality increased to the same extent in both lactating and non-mated animals. 2. Following water deprivation, the water intake of the lactating rats was significantly less than that of the pregnant, post-lactating or non-mated animals when expressed as a percentage of the weight loss during dehydration. While the non-mated rats restored their plasma osmolality to the pre-deprivation value upon drinking, the lactating rats sustained a new decrease in osmolality despite the fact that their mean haematocrit was still elevated. 3. When the dehydrated animals were given isotonic saline to drink instead of water, both lactating and non-mated animals restored their body weight and haematocrit to pre-deprivation levels. 4. Lactating rats showed a reduced absolute and net fluid intake in response to I.V. hypertonic saline which could not be explained by more rapid renal clearance of the solute. 5. The pregnant and lactating rats drank less in response to s.c. isoprenaline than did the post-lactating and non-mated animals. 6. The spontaneous 3 hr fluid intake was significantly less during lactation. 7. It is suggested that during the hours of daylight, lactating rats are less responsive to dipsogenic stimuli arising from deficits in both their intracellular and extracellular fluid spaces.
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Selected References
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- Atkinson J., Kaesermann H. P., Lambelet J., Peters G., Peters-Haefeli L. The role of circulating renin in drinking in response to isoprenaline. J Physiol. 1979 Jun;291:61–73. doi: 10.1113/jphysiol.1979.sp012800. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baverstock P., Green B. Water recycling in lactation. Science. 1975 Feb 21;187(4177):657–658. doi: 10.1126/science.1167701. [DOI] [PubMed] [Google Scholar]
- Blaine E. H., Covelli M. D., Denton D. A., Nelson J. F., Shulkes A. A. The role of ACTH and adrenal glucocorticoids in the salt appetite of wild rabbits (Oryctolagus cuniculus (L)). Endocrinology. 1975 Oct;97(4):793–801. doi: 10.1210/endo-97-4-793. [DOI] [PubMed] [Google Scholar]
- Covelli M. D., Denton D. A., Nelson J. F., Shulkes A. A. Hormonal factors influencing salt appetite in pregnancy. Endocrinology. 1973 Aug;93(2):423–429. doi: 10.1210/endo-93-2-423. [DOI] [PubMed] [Google Scholar]
- Denton D. A., Nelson J. F. The effects of pregnancy and lactation on the mineral appetites of wild rabbits (Oryctolagus Cuniculus (L.)). Endocrinology. 1971 Jan;88(1):31–40. doi: 10.1210/endo-88-1-31. [DOI] [PubMed] [Google Scholar]
- Findlay A. L., Fitzsimons J. T., Kucharczyk J. Dependence of spontaneous and angiotensin-induced drinking in the rat upon the oestrous cycle and ovarian hormones. J Endocrinol. 1979 Aug;82(2):215–225. doi: 10.1677/joe.0.0820215. [DOI] [PubMed] [Google Scholar]
- Kaufman S. Chronic, nonocclusive, and maintenance-free central venous cannula in the rat. Am J Physiol. 1980 Jul;239(1):R123–R125. doi: 10.1152/ajpregu.1980.239.1.R123. [DOI] [PubMed] [Google Scholar]
- Kutscher C. L. Hematocrit, plasma osmolality, and plasma protein concentration as estimators of plasma volume in hooded rats during food and water deprivation. Physiol Behav. 1971 Aug;7(2):283–285. doi: 10.1016/0031-9384(71)90302-7. [DOI] [PubMed] [Google Scholar]
- Morishige W. K., Pepe G. J., Rothchild I. Serum luteinizing hormone, prolactin and progesterone levels during pregnancy in the rat. Endocrinology. 1973 May;92(5):1527–1530. doi: 10.1210/endo-92-5-1527. [DOI] [PubMed] [Google Scholar]
- Shulkes A. A., Covelli M. D., Denton D. A., Nelson J. F. Hormonal factors influencing salt appetite in lactation. Aust J Exp Biol Med Sci. 1972 Dec;50(7):819–826. doi: 10.1038/icb.1972.79. [DOI] [PubMed] [Google Scholar]
- Tarttelin M. F., Gorski R. A. Variations in food and water intake in the normal and acyclic female rat. Physiol Behav. 1971 Dec;7(6):847–852. doi: 10.1016/0031-9384(71)90050-3. [DOI] [PubMed] [Google Scholar]
- Thrasher T. N., Fregly M. J. Effect of chronic treatment with an estrogen-progestogen combination on beta adrenergic-induced thirst. Pharmacol Biochem Behav. 1978 Feb;8(2):177–183. doi: 10.1016/0091-3057(78)90334-9. [DOI] [PubMed] [Google Scholar]
- Yoshinaga K., Hawkins R. A., Stocker J. F. Estrogen secretion by the rat ovary in vivo during the estrous cycle and pregnancy. Endocrinology. 1969 Jul;85(1):103–112. doi: 10.1210/endo-85-1-103. [DOI] [PubMed] [Google Scholar]