Effect of a Low Bulk Diet on Water and Electrolyte Exchange in Rats Exposed to Cold

1971 ◽  
Vol 49 (11) ◽  
pp. 959-966 ◽  
Author(s):  
Melvin J. Fregly
Keyword(s):  
Water Intake ◽  
Cold Exposure ◽  
Urine Output ◽  
Potassium Excretion ◽  
Drinking Response ◽  
High Bulk ◽  
Sodium And Potassium ◽  
Electrolyte Exchange

Exposure of rats to air at 6 °C for 10 days increased both intake of a low bulk diet and urine output, but failed to affect water intake. A comparison of urine output with water intake revealed a greater urine output at a given water intake in cold-exposed than in control rats. This suggests a possible mechanism for the relative dehydration induced by cold exposure. Both fecal and urinary routes of sodium and potassium excretion were increased by cold exposure. Fecal excretions of both sodium and potassium were similar fractions of their total outputs prior to, as well as during, cold exposure. In addition, both sodium and potassium exchanges were unaltered by cold exposure. These results suggest that the greater fecal sodium and potassium excretions observed previously with a high bulk food are related to fecal bulk and not to cold exposure per se.A post-cold drinking response was observed at 1, 2, and 3 h after removal from cold and is consistent with maintenance on a low bulk diet.

Water and electrolyte exchange in rats exposed to cold

1968 ◽  
Vol 46 (6) ◽  
pp. 873-881 ◽  
Author(s):  
Melvin J. Fregly
Keyword(s):  
Food Intake ◽  
Water Intake ◽  
Cold Exposure ◽  
Urine Output ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Total Output ◽  
Electrolyte Loss ◽  
Sodium And Potassium ◽  
Electrolyte Exchange

Exposure of rats to air at 6 °C for 10 days increased food intake and urine output but failed to affect water intake. A comparison of water with food intake revealed a smaller water intake for a given food intake for cold-exposed than for control rats. The urine output at a given water intake was also greater for cold-exposed rats. In addition, cold exposure failed to affect urine osmolality significantly. Thus, the greater solute output accompanying cold exposure was accomplished by increasing urine flow rather than by concentrating urine. These results suggest possible mechanisms for both the relative dehydration and increased plasma osmolality observed after removal of rats from cold air. Both fecal and urinary routes of sodium and potassium excretion were increased by cold exposure; however, fecal excretions of both potassium and sodium were greater fractions of the total output during cold exposure than prior to it. Although cold exposure tends to induce a relative dehydration in rats, an important factor limiting the extent of the dehydration may be increased fecal electrolyte loss.

Nalfurafine, a G-Protein–Biased KOR (Kappa Opioid Receptor) Agonist, Enhances the Diuretic Response and Limits Electrolyte Losses to Standard-of-Care Diuretics

Hypertension ◽  
2021 ◽  
Author(s):  
Jacob K. Meariman ◽  
Jane C. Sutphen ◽  
Juan Gao ◽  
Daniel R. Kapusta
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Urine Output ◽  
Receptor Agonist ◽  
Standard Of Care ◽  
Kappa Opioid Receptor ◽  
Potassium Excretion ◽  
Kappa Opioid ◽  
Opioid Receptor Agonist ◽  
Sodium And Potassium

Nalfurafine is a G-protein–biased KOR (kappa opioid receptor) agonist that produces analgesia and lacks CNS adverse effects. Here, we examined the cardiovascular and renal responses to intravenous and oral nalfurafine alone and in combination with furosemide, hydrochlorothiazide, or amiloride. We hypothesized that nalfurafine, given its distinct mechanism of vasopressin inhibition, would increase urine output to these diuretics and limit electrolyte loss. Following catheterization, conscious Sprague-Dawley rats received an isotonic saline infusion and were then administered an intravenous bolus of nalfurafine, a diuretic, or a combination. Mean arterial pressure, heart rate, and urine output were recorded for 90 minutes. In another study, rats were placed in metabolic cages and administered drug in an oral volume load. Hourly urine samples were then collected for 5 hours. Intravenous and oral nalfurafine produced a marked diuresis, antinatriuresis, antikaliuresis, and a decrease in mean arterial pressure. Compared with diuretic treatment alone, intravenous coadministration with nalfurafine significantly increased urine output to furosemide and hydrochlorothiazide and decreased sodium and potassium excretion. Notably, mean arterial pressure was reduced with nalfurafine/diuretic combination therapy compared to diuretics alone. Similarly, oral coadministration of nalfurafine significantly increased urine output to hydrochlorothiazide and decreased sodium and potassium excretion, whereas combination with furosemide only limited the amount of sodium excreted. Further, both intravenous and oral coadministration of nalfurafine enhanced the diuresis to amiloride and decreased sodium excretion. Together, these findings demonstrate that nalfurafine enhances the diuresis to standard-of-care diuretics without causing an excessive loss of electrolytes, offering a new approach to treat several cardiovascular conditions.

Rhythmic changes in renal function in the rat

1965 ◽  
Vol 209 (6) ◽  
pp. 1187-1192 ◽  
Author(s):  
George A. Bray
Keyword(s):  
Renal Function ◽  
Cold Exposure ◽  
Sodium Excretion ◽  
Urine Output ◽  
Sodium Intake ◽  
Urine Volume ◽  
Potassium Excretion ◽  
Electrolyte Excretion ◽  
Threefold Increase ◽  
Electrolyte Intake

Cold exposure causes rats to increase their urine output. This increase in urine output was found to occur in 5- to 8-day cycles with peak urine volumes three or more times the volumes prior to exposure to the cold. Cycles in urine volume occurred on a constant electrolyte intake and in animals receiving exogenous Pitressin. The peaks in urine volume were accompanied by a threefold increase in the variability of sodium excretion but not potassium excretion. The increase in urine volume which occurred at the same time in all rats in a group began at night and continued through the following day. These data have been discussed in the light of a possible mechanism controlling sodium intake with water intake and electrolyte excretion.

scholarly journals Association between 24-h urinary sodium and potassium excretion and blood pressure among Chinese adults aged 18–69 years

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaofu Du ◽  
Le Fang ◽  
Jianwei Xu ◽  
Xiangyu Chen ◽  
Yamin Bai ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Sodium Intake ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Inverse Association ◽  
Potassium Excretion ◽  
Chinese Adults ◽  
Potassium Intake ◽  
Sodium And Potassium

AbstractThe direction and magnitude of the association between sodium and potassium excretion and blood pressure (BP) may differ depending on the characteristics of the study participant or the intake assessment method. Our objective was to assess the relationship between BP, hypertension and 24-h urinary sodium and potassium excretion among Chinese adults. A total of 1424 provincially representative Chinese residents aged 18 to 69 years participated in a cross-sectional survey in 2017 that included demographic data, physical measurements and 24-h urine collection. In this study, the average 24-h urinary sodium and potassium excretion and sodium-to-potassium ratio were 3811.4 mg/day, 1449.3 mg/day, and 4.9, respectively. After multivariable adjustment, each 1000 mg difference in 24-h urinary sodium excretion was significantly associated with systolic BP (0.64 mm Hg; 95% confidence interval [CI] 0.05–1.24) and diastolic BP (0.45 mm Hg; 95% CI 0.08–0.81), and each 1000 mg difference in 24-h urinary potassium excretion was inversely associated with systolic BP (− 3.07 mm Hg; 95% CI − 4.57 to − 1.57) and diastolic BP (− 0.94 mm Hg; 95% CI − 1.87 to − 0.02). The sodium-to-potassium ratio was significantly associated with systolic BP (0.78 mm Hg; 95% CI 0.42–1.13) and diastolic BP (0.31 mm Hg; 95% CI 0.10–0.53) per 1-unit increase. These associations were mainly driven by the hypertensive group. Those with a sodium intake above about 4900 mg/24 h or with a potassium intake below about 1000 mg/24 h had a higher risk of hypertension. At higher but not lower levels of 24-h urinary sodium excretion, potassium can better blunt the sodium-BP relationship. The adjusted odds ratios (ORs) of hypertension in the highest quartile compared with the lowest quartile of excretion were 0.54 (95% CI 0.35–0.84) for potassium and 1.71 (95% CI 1.16–2.51) for the sodium-to-potassium ratio, while the corresponding OR for sodium was not significant (OR, 1.28; 95% CI 0.83–1.98). Our results showed that the sodium intake was significantly associated with BP among hypertensive patients and the inverse association between potassium intake and BP was stronger and involved a larger fraction of the population, especially those with a potassium intake below 1000 mg/24 h should probably increase their potassium intake.

scholarly journals Assessment of Foods Associated with Sodium and Potassium Intake in Japanese Youths Using the Brief-Type Self-Administered Diet History Questionnaire

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2345
Author(s):  
Masayuki Okuda ◽  
Satoshi Sasaki
Keyword(s):  
Sodium Excretion ◽  
Sodium Intake ◽  
Molar Ratio ◽  
Potassium Excretion ◽  
Potassium Intake ◽  
Soybean Paste ◽  
Diet History Questionnaire ◽  
Diet History ◽  
8Th Graders ◽  
Sodium And Potassium

The identification of sodium and potassium intake in youths is an important step to preventing the increase of blood pressure in childhood. We examined food intake and estimated mineral intake using a brief-type self-administered diet history questionnaire (BDHQ) to test its validity as a comparison with urinary excretion in Japanese youths. The subjects were 5th and 8th graders (n = 2377), who completed the BDHQ and permitted the use of their overnight urine specimens. Sodium intake was poorly associated with sodium excretion (Rho = 0.048), and the coefficients of dietary potassium and a sodium-to-potassium molar ratio were 0.091–0.130. Higher soybean paste (miso) intake and pickles were significantly associated with higher sodium excretion (p ≤ 0.005). However, these foods were positively associated with potassium excretion (p = 0.002–0.012), and not associated with an excreted sodium-to-potassium ratio. Fruits and dairy products were positively associated (p ≤ 0.048), whereas beverages were negatively associated with potassium excretion (p ≤ 0.004). The association of the sodium-to-potassium ratio was opposite to that of potassium (p ≤ 0.001). The choice of foods, potassium, and the sodium-to-potassium ratio assessed using the BDHQ are available as part of health education for youths, but the assessment of sodium intake in population levels should be carefully conducted.

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