The Effects of Salt and Water Loading on Kidney Function in Healthy Undergraduates
Advances in Applied Physiology
Volume 4, Issue 2, December 2019, Pages: 11-18
Received: Oct. 8, 2019;
Accepted: Nov. 6, 2019;
Published: Nov. 17, 2019
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Ehmann Peter J., Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Brush Christopher J., Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA; Department of Psychology, Florida State University, Tallahassee, USA
Bozzini Brittany, Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Dowden Robert A., Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Ogilvie Anna, Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Wisniewski Paul J., Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Bernard Laura P., Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Merrill Gary F., Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, USA
Rutgers University juniors and seniors enrolled in Systems Physiology Laboratory (01:146:356) Spring, 2019. One-hundred forty-five students volunteered to test the effects of salt and water loading on kidney function. Students were investigated beginning at 8:40 a.m., 1:40 p.m., and 6:40 p.m. They were approximately evenly distributed between male and female genders and were of multiple cultural/ethnic backgrounds. Upon entering the laboratory baseline data were collected. Approximately half of the volunteers then consumed 200 mL of a 2.0% NaCl solution (n=77). The others directly consumed 1.0 L of tap water (n=68). Upon entering the laboratory baseline data were collected. The others directly consumed 1.0 L of tap water. Kidney function was monitored each 30 minutes for the next 90 minutes. Under baseline conditions, urine osmolality was elevated in all students (≥ 280 mOsm/kg) but was significantly (P<0.05) greater in the 8:40 a.m. group than in either of the p.m. groups. Urine specific gravity and sodium excretion were also elevated in the 8:40 a.m. group compared to the others. Urine flow rate was least in the 8:40 group and greatest in the 1:40 p.m. group. We conclude that in these students renal function was influenced by a diurnal pattern. We also conclude that without compelling incentives (e.g. financial, grade-influencing) it was virtually impossible to get students to comply with pre-experimental instructions (e.g. no salt-laden meals after 6:00 p.m. before the day of experimentation).
Ehmann Peter J.,
Brush Christopher J.,
Dowden Robert A.,
Wisniewski Paul J.,
Bernard Laura P.,
Merrill Gary F.,
The Effects of Salt and Water Loading on Kidney Function in Healthy Undergraduates, Advances in Applied Physiology.
Vol. 4, No. 2,
2019, pp. 11-18.
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