Sodium plays an important role in the absorption of intravesical fluid

Abstract

Objectives: To investigate the role of sodium in intravesical absorption of water in the bladder and the sodium pathway in the urothelium. Methods: Adult female Sprague-Dawley rats received either saline or a 5% glucose solution injection into their bladders. The changes in intravesical fluid volume; concentrations of sodium and chlorine and osmolality; and expression of aquaporin-2, epithelial sodium channel, and claudins were compared after 3 hours. Results: Intravesical volume decreased significantly in the saline group compared to that in the 5% glucose solution group. The expression of claudin-3 and-6 was higher in the saline group than in the glucose group. There was a significant correlation between changes in the intravesical saline volume and the concentration of sodium and chlorine. Intravesical administration of amiloride did not affect changes in the fluid volume and concentration of sodium. Conclusions: The presence of sodium is important for the absorption of intravesical fluid through aquaporin-2 in the urinary bladders of rats. Claudin-3 and-6 may be associated with the transport of sodium through the bladder urothelium.

Urinary Reabsorption in the Rat Kidney by Anticholinergics

“…8 The bladder epithelium has a role in sodium transport, possibly via epithelial sodium channels (ENaCs) or claudin-3,6. 16,17 In humans, > 100 ml of bladder urine disappears during sleep at night, when the bladder capacity reaches its functional limit as shown by the time-course monitoring of bladder capacity by transabdominal 3D ultrasound. 18 Our present ndings in an animal model con rmed that physiological saline and glucose solution injected into the rat bladder were each absorbed through the bladder.…”

Enhancing Therapeutic Efficacy and Safety of Immune Checkpoint Inhibition for Bladder Cancer: A Comparative Analysis of Injectable vs. Intravesical Administration

“…Since absorbed mitomycin is excreted renally, an increase in the systemic absorption of mitomycin [34] with longer dwell time of 1 h rather than 0.5 h in BC patients [34] can be ascertained from Mitomycin levels excreted in urine and higher urine levels of excreted Mitomycin coincided with a significant reduction of cancer recurrence [33,48]. The role of venous outflow in maintaining static urothelial drug levels after intravesical therapy is also corroborated by the blood levels of drugs in patients without BC [49,50] and by systemic absorption of radiolabeled urea, sodium and radio-iodinated albumin in accordance with the Stokesian diffusion principle [30,31] (see Figure 1). While the systemic absorption of intravesical pembrolizumab could be heightened by immature tight junctions of undifferentiated high-grade tumors and carcinoma in situ but the low assay sensitivity and inefficient timing of blood sampling could still contribute to the undetectable blood levels of pembrolizumab in BC patients exhibiting characteristic ICI toxicity after intravesical pembrolizumab [25].…”

“…The antitumor immune response evoked by a single dose of pembrolizumab and its higher systemic toxicity in combination with BCG implicates that stark differences in the pharmacokinetics and pharmacodynamics of intravesical pembrolizumab and BCG were compounded by the differences in regimen of two entities. A higher systemic toxicity of intravesical pembrolizumab can be logically traced to a higher systemic absorption of a 200 times smaller molecule than BCG [28,29] as inverse size dependence of Stokesian diffusion principle dictates faster diffusion of smaller molecules and slower diffusion of macromolecules [30,31]. Moreover, the systemic uptake of pembrolizumab into bladder mucosa after intravesical administration for ≥30 min is assured by the tumoritropic infiltration of macromolecules of comparable size such as radiolabeled dextran-99mTechnetium conjugated to epidermal growth factor (EGF) after 30 min instillation in non-muscle invasive BC patients [32].…”

SWOT and Root Cause Analyses of Antimicrobial Resistance to Oral Antimicrobial Treatment of Cystitis

“…The bladder participates in homeostasis via endocrine and stretch-mediated urine reabsorption [9,51,52,54,55] to match with the constant-but-slow rate of urine production during sleep [56]. The multicellular layer of the urothelium [57] lining the bladder is a highly metabolically active [12] multifunctional tissue for monitoring bladder distension [58] and signaling constitutional changes in urine [53,59,60] to the detrusor, micturition centers, and the immune system [61]. The top layer of the urothelium relies on the restricted transcellular permeability [62] of the umbrella cells endowed with the asymmetric membrane on the apical side to survive the low pH and three-fold-higher osmotic pressure of urine [9,63] than the serum (Figure 1).…”