Evaluation of voiding assays in mice: impact of genetic strains and sex

Abstract

Void spot assays (VSA) and cystometry are two of the most common tests performed in mice to assess lower urinary tract function. Assay protocols and methodology vary greatly among laboratories, and little is known about reproducibility of results generated by different laboratories. We performed VSA in four mouse strains, comparing males with females and comparing results between two independent laboratories. Unique aspects of the current study include direct comparison of results of VSA performed in a similar manner in two locations and comparison of cystometry performed using two different rates of infusion in these two laboratories. Both assays were performed in male and female 129S1/SvImJ, C57BL/6J, NOD/ShiLtJ, and CAST/EiJ mice, and cystometry was performed under urethane anesthesia (10/group). Assays were performed and results analyzed as previously described. Results obtained in female mice were compared with previously reported values. Results of lower urinary tract function testing in mice vary in a consistent manner with strain and sex. Variables in husbandry, testing techniques, and analysis of results can significantly affect conclusions, particularly those obtained by cystometry. Although VSA results were remarkably similar between the two laboratories, consistent methods for performing lower urinary tract function testing in mice are required to compare results among studies with confidence.

Chronic high‐fat diet decreased detrusor mitochondrial respiration and increased nerve‐mediated contractions

“…Individual void spots were counted and their areas were measured using ImageJ (NIH, Bethesda, MD). Bright spots smaller than 0.06 cm 2 were eliminated to account for grid "spray" and nonurine particles . The VSA parameters measured were: the number of voids, the total void area, the average area per void, and the area of the primary (largest) void.…”

Factors Driving Unique Urination Phenotypes of Male and Female 9-week-old C57BL/6J Mice

“…Cystometry was performed with minimal alterations to previously published protocols. 31, 32 Mice were anesthetized with urethane (1.43 g/kg sc). Thirty minutes after urethane dosing, an incision was made in the ventral abdomen to expose the bladder.…”

Mouse urothelial genes associated with voiding behavior changes after ovariectomy and bladder lipopolysaccharide exposure

“…Total urine spots on filter paper were subsequently visualized under UV light and digitally photographed. Images were converted to black and white, and quantitation was performed with ImageJ software . VSA were performed at the time points depicted in Figure .…”

“…Images were converted to black and white, and quantitation was performed with ImageJ software. 7 VSA were performed at the time points depicted in Figure 1.…”

“…Voiding behavior was measured in the conscious, unrestrained mouse using published method of voiding spot assays (VSA). 7 We performed urothelial microarray hybridization at different time points and searched for changes in gene expression that correlated significantly with voiding behavior changes.…”