Related Experiment Videos
[Superoxide anion generation of human polymorphonuclear leukocytes in urine]
Abstract:
In order to clarify the role of polymorphonuclear leukocytes (PMNs) in the defence mechanism of the urinary tract, we investigated the superoxide anion (O2-) generation of PMNs in the urine. We tested urines mixing concentrated urine with diluted ones in various ratios. Peripheral blood derived PMNs were stimulated in tested urines or phosphate buffer solution (1M, pH 7.0) with phorbol-myristate acetate and O2- generation of PMNs was measured by means of chemiluminescence (CL) method. The CL values of PMNs in tested urines were 1/30 that of phosphate buffer solution. However, PMNs generated O2- at maximum levels when the urine osmolarity was 300-400 mOsm/kg. Furthermore, PMNs did not generate O2- when the urine osmolarity was more than 600 mOsm/kg, or less than 200 mOsm/kg. We also investigated the influence of urea and creatinine on O2- generation of PMNs. The O2- generation of PMNs decreased when the urea concentration rose. However, there was no influence of creatinine on O2- generation of PMNs. From these results, it was elucidated that PMNs generated O2- when the urine osmolarity was 300-400 mOsm/kg. Therefore, urine osmolarity of the patients with urinary tract infection should be kept at 300-400 mOsm/kg, and diuresis might be important for the patients with urinary tract infection.
Insights
Polymorphonuclear leukocytes (PMNs) generate superoxide anions in urine optimally at 300-400 mOsm/kg. Urine osmolarity significantly impacts PMN function in urinary tract infections, with higher or lower levels inhibiting this crucial defense mechanism.
Area of Science:
- Urology
- Immunology
- Nephrology
Context:
- Urinary tract infections (UTIs) involve complex host-pathogen interactions.
- Polymorphonuclear leukocytes (PMNs) are critical immune cells in combating UTIs.
- Understanding PMN function in the urinary tract environment is essential for effective treatment strategies.
Purpose:
- To investigate the role of urine osmolarity and composition on polymorphonuclear leukocyte (PMN) superoxide anion (O2-) generation.
- To determine the optimal urine osmolarity range for PMN O2- generation.
- To assess the influence of urea and creatinine on PMN function in urine.
Summary:
- PMN O2- generation, measured by chemiluminescence, was significantly reduced in urine compared to buffer.
- Optimal PMN O2- generation occurred at urine osmolarity of 300-400 mOsm/kg.
- PMN O2- generation was inhibited at osmolarities above 600 mOsm/kg or below 200 mOsm/kg.
- Increased urea concentration decreased PMN O2- generation, while creatinine had no significant effect.
Impact:
- Findings suggest that maintaining urine osmolarity between 300-400 mOsm/kg may enhance PMN-mediated defense against UTIs.
- Diuresis could be a beneficial supportive therapy for patients with urinary tract infections.
- This research provides a basis for optimizing fluid management in UTI treatment.