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Renal and endocrine responses in the elderly during head-out water immersion.
Am J Physiol. 1988 Jun; 254(6 Pt 2):R977-83.AJ

Abstract

After overnight food and fluid restriction, seven healthy old (62-74 yr) and eight young (21-28 yr) men were examined before, during, and after 3-h head-out immersion (HOI) in thermoneutral water (34.5 +/- 0.5 degrees C). On separate days, all subjects remained seated in air for 5 h to obtain the time control data. Although HOI induced a reversible increase in urine flow in all subjects, the response was faster and greater in magnitude in the elderly than in the young. Na excretion and osmolal clearance also followed a response pattern identical to that of urine flow; thus the HOI-induced diuresis was entirely osmotic. Endogenous creatinine clearance increased in the elderly at 2 h of HOI, suggesting an age-related modification in kidney hemodynamics. Although there was virtually the same cephalad blood shift (measured by impedance cardiography), mean arterial pressure significantly increased (P less than 0.05) during HOI in the elderly, which also indicated a different response of peripheral circulation to HOI in the elderly. Control level of plasma atrial natriuretic factor (ANF) was nearly twofold greater in the elderly compared with the young. The HOI induced a nearly fourfold increase in ANF in the elderly, whereas that for the young was threefold. Both plasma aldosterone and ADH responses to HOI were attenuated in the elderly compared with the young, which had no correlation with urine flow or Na excretion. It is concluded that the elderly release more ANF at a given cephalad volume expansion compared with the young, but the vasodilative reaction to ANF was attenuated in the elderly.

Authors+Show Affiliations

Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

2968055

Citation

Tajima, F, et al. "Renal and Endocrine Responses in the Elderly During Head-out Water Immersion." The American Journal of Physiology, vol. 254, no. 6 Pt 2, 1988, pp. R977-83.
Tajima F, Sagawa S, Iwamoto J, et al. Renal and endocrine responses in the elderly during head-out water immersion. Am J Physiol. 1988;254(6 Pt 2):R977-83.
Tajima, F., Sagawa, S., Iwamoto, J., Miki, K., Claybaugh, J. R., & Shiraki, K. (1988). Renal and endocrine responses in the elderly during head-out water immersion. The American Journal of Physiology, 254(6 Pt 2), R977-83.
Tajima F, et al. Renal and Endocrine Responses in the Elderly During Head-out Water Immersion. Am J Physiol. 1988;254(6 Pt 2):R977-83. PubMed PMID: 2968055.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Renal and endocrine responses in the elderly during head-out water immersion. AU - Tajima,F, AU - Sagawa,S, AU - Iwamoto,J, AU - Miki,K, AU - Claybaugh,J R, AU - Shiraki,K, PY - 1988/6/1/pubmed PY - 1988/6/1/medline PY - 1988/6/1/entrez SP - R977 EP - 83 JF - The American journal of physiology JO - Am. J. Physiol. VL - 254 IS - 6 Pt 2 N2 - After overnight food and fluid restriction, seven healthy old (62-74 yr) and eight young (21-28 yr) men were examined before, during, and after 3-h head-out immersion (HOI) in thermoneutral water (34.5 +/- 0.5 degrees C). On separate days, all subjects remained seated in air for 5 h to obtain the time control data. Although HOI induced a reversible increase in urine flow in all subjects, the response was faster and greater in magnitude in the elderly than in the young. Na excretion and osmolal clearance also followed a response pattern identical to that of urine flow; thus the HOI-induced diuresis was entirely osmotic. Endogenous creatinine clearance increased in the elderly at 2 h of HOI, suggesting an age-related modification in kidney hemodynamics. Although there was virtually the same cephalad blood shift (measured by impedance cardiography), mean arterial pressure significantly increased (P less than 0.05) during HOI in the elderly, which also indicated a different response of peripheral circulation to HOI in the elderly. Control level of plasma atrial natriuretic factor (ANF) was nearly twofold greater in the elderly compared with the young. The HOI induced a nearly fourfold increase in ANF in the elderly, whereas that for the young was threefold. Both plasma aldosterone and ADH responses to HOI were attenuated in the elderly compared with the young, which had no correlation with urine flow or Na excretion. It is concluded that the elderly release more ANF at a given cephalad volume expansion compared with the young, but the vasodilative reaction to ANF was attenuated in the elderly. SN - 0002-9513 UR - https://www.unboundmedicine.com/medline/citation/2968055/Renal_and_endocrine_responses_in_the_elderly_during_head_out_water_immersion_ L2 - http://www.physiology.org/doi/full/10.1152/ajpregu.1988.254.6.R977?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -