Urine pH Variation Dynamics in Healthy Individuals and Stone Formers

Abstract

Urine pH density distribution curves have been obtained in groups of patients with concrements of various chemical compositions. Quantitative regularities for mixing chemical compounds in the concrements established by the infrared spectroscopic method have been shown to agree with urine pH distribution density (in time). Potential physicochemical mechanisms for the revealed generality are considered. In particular, it is indicated that urine pH variations display in the first approximation buffer effect of the concrement components. A Fourier analysis of pH variations in the homogeneous urine of healthy individuals and in the systems of urine versus concrement as a time function has been made. Urine pH variations observed have been shown to be approximated by the superposition of harmonic vibrations with a range of frequencies multiple of the diurnal one. It has been found that a distinctly pronounced and complicated gamut of pH fluctuations over the entire physiological range of values (i.e. 4.5–8.5) is typical of healthy individuals in contrast to the stone formers.

Effect of acute acid loading on acid–base and calcium metabolism

“…Thus, one explanation for the marginally reduced levels of renal NA excretion during acid loading in the stone-formers may be that their kidneys experienced a reduced acid load compared to the controls due to a higher rate of NB mobilization from bone and soft tissue. Such a mechanism may also explain why calcium stoneformers frequently have higher levels of pH(U) [22,23]. The present data confirm that acid loading results in increased concentrations of ionized calcium in serum [cCa 2' (S)] [17].…”

Update on the Pathophysiology and Management of Uric Acid Renal Stones

“…Increased net acid excretion (NAE) and titratable acidity has been observed in uric acid stone formers as well , even on fixed diets. [20,27,28] The biochemical origin of these findings is unclear but may be related to endogenous organic acids [38], or impaired post-prandial alkaline tide [39,40].…”

Urinary Tract Physiological Conditions Promote Ciprofloxacin Resistance in Low-Level-Quinolone-Resistant Escherichia coli

“…Urine is a fluctuating and complex fluid composed of over 95% water, plus sodium, ammonia, phosphate, sulfate, urea, creatinine, proteins, and products processed by the kidney and liver (11). The variability in the physicochemical properties of urine is best illustrated by the wide pH range of human urine, which normally varies from 5 to 8 (12). Additionally, the bladder environment is mainly anaerobic, with a concentration of dissolved oxygen (DO) in urine of about 4.2 ppm (13); the concentration is also variable and mainly reflects the renal metabolic state.…”