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Human Urinary Bladder Strip Relaxation by the β-Adrenoceptor Agonist Isoprenaline: Methodological Considerations and Effects of Gender and Age.

Schneider T, Fetscher C, Michel MC - Front Pharmacol (2011)

Bottom Line: Storage of detrusor strips in cold buffer for up to 2 days did not affect contractile responses to KCl or efficacy of isoprenaline to cause relaxation but significantly affected the isoprenaline potency.The type (KCl vs. passive tension) or strength of contractile stimulus had only minor effects on isoprenaline responses although these differences reached statistical significance in some cases.Similarly, gender and age had only minor if any effects on KCl-induced contraction or isoprenaline-induced relaxation, but the current data are too limited for robust conclusions.

View Article: PubMed Central - PubMed

Affiliation: Departments of Urology and Medicine, University of Duisburg-Essen Essen, Germany.

ABSTRACT
The present study was primarily designed to explore various methodological aspects related to organ bath experiments evaluating human detrusor relaxation by the β-adrenoceptor agonist isoprenaline. Data are based upon a series of 30 consecutive patients, and this cohort was also used to explore possible effects of gender and age. KCl-induced contraction was related to strip length but not weight or cross-sectional area, indicating that the former is most suitable for data normalization. Storage of detrusor strips in cold buffer for up to 2 days did not affect contractile responses to KCl or efficacy of isoprenaline to cause relaxation but significantly affected the isoprenaline potency. No such alterations were observed with up to 1 day of cold storage. The type (KCl vs. passive tension) or strength of contractile stimulus had only minor effects on isoprenaline responses although these differences reached statistical significance in some cases. Similarly, gender and age had only minor if any effects on KCl-induced contraction or isoprenaline-induced relaxation, but the current data are too limited for robust conclusions. In summary we have evaluated experimental conditions for the testing of human detrusor strip contraction and relaxation which should be useful for future larger studies.

No MeSH data available.


Related in: MedlinePlus

Effect of gender and age on contractile responses to 50 mM KCl. Each data point represents one patient (25 males, 5 females, 1–6 strips per patient), whereas the bars in the upper panel represent the group means.
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Figure 3: Effect of gender and age on contractile responses to 50 mM KCl. Each data point represents one patient (25 males, 5 females, 1–6 strips per patient), whereas the bars in the upper panel represent the group means.

Mentions: While KCl responses were numerically about a third lower in strips from female as compared to male patients, the difference did not reach statistical significance with the limited number of patients (Figure 3). Pooling data from both genders, KCl responses tended to decrease with age but this also failed to reach statistical significance (Figure 3). If only male patients were considered, the association between age and contraction also lacked statistical significance (r2 = 0.0349; p = 0.1891). However, in both cases the youngest patient, who had a very small response, appeared to affect the correlation analysis; if he was excluded from the analysis, the inverse association between age and KCl response remained very weak but became statistically significant (r2 = 0.0934; p = 0.0133) in the pooled group of both genders.


Human Urinary Bladder Strip Relaxation by the β-Adrenoceptor Agonist Isoprenaline: Methodological Considerations and Effects of Gender and Age.

Schneider T, Fetscher C, Michel MC - Front Pharmacol (2011)

Effect of gender and age on contractile responses to 50 mM KCl. Each data point represents one patient (25 males, 5 females, 1–6 strips per patient), whereas the bars in the upper panel represent the group means.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108483&req=5

Figure 3: Effect of gender and age on contractile responses to 50 mM KCl. Each data point represents one patient (25 males, 5 females, 1–6 strips per patient), whereas the bars in the upper panel represent the group means.
Mentions: While KCl responses were numerically about a third lower in strips from female as compared to male patients, the difference did not reach statistical significance with the limited number of patients (Figure 3). Pooling data from both genders, KCl responses tended to decrease with age but this also failed to reach statistical significance (Figure 3). If only male patients were considered, the association between age and contraction also lacked statistical significance (r2 = 0.0349; p = 0.1891). However, in both cases the youngest patient, who had a very small response, appeared to affect the correlation analysis; if he was excluded from the analysis, the inverse association between age and KCl response remained very weak but became statistically significant (r2 = 0.0934; p = 0.0133) in the pooled group of both genders.

Bottom Line: Storage of detrusor strips in cold buffer for up to 2 days did not affect contractile responses to KCl or efficacy of isoprenaline to cause relaxation but significantly affected the isoprenaline potency.The type (KCl vs. passive tension) or strength of contractile stimulus had only minor effects on isoprenaline responses although these differences reached statistical significance in some cases.Similarly, gender and age had only minor if any effects on KCl-induced contraction or isoprenaline-induced relaxation, but the current data are too limited for robust conclusions.

View Article: PubMed Central - PubMed

Affiliation: Departments of Urology and Medicine, University of Duisburg-Essen Essen, Germany.

ABSTRACT
The present study was primarily designed to explore various methodological aspects related to organ bath experiments evaluating human detrusor relaxation by the β-adrenoceptor agonist isoprenaline. Data are based upon a series of 30 consecutive patients, and this cohort was also used to explore possible effects of gender and age. KCl-induced contraction was related to strip length but not weight or cross-sectional area, indicating that the former is most suitable for data normalization. Storage of detrusor strips in cold buffer for up to 2 days did not affect contractile responses to KCl or efficacy of isoprenaline to cause relaxation but significantly affected the isoprenaline potency. No such alterations were observed with up to 1 day of cold storage. The type (KCl vs. passive tension) or strength of contractile stimulus had only minor effects on isoprenaline responses although these differences reached statistical significance in some cases. Similarly, gender and age had only minor if any effects on KCl-induced contraction or isoprenaline-induced relaxation, but the current data are too limited for robust conclusions. In summary we have evaluated experimental conditions for the testing of human detrusor strip contraction and relaxation which should be useful for future larger studies.

No MeSH data available.


Related in: MedlinePlus