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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

Role of normalization of contractile responses to 50 mM KCl based upon strip length (upper panel), weight (middle panel), or calculated cross-sectional area (lower panel). Each data represents one strip (in total 66 strips from 30 patients), and data obtained on days 0–2 were included.
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Figure 1: Role of normalization of contractile responses to 50 mM KCl based upon strip length (upper panel), weight (middle panel), or calculated cross-sectional area (lower panel). Each data represents one strip (in total 66 strips from 30 patients), and data obtained on days 0–2 were included.

Mentions: We first analyzed how strip size and storage might affect contractile responses to KCl. Using only the 34 strips from 23 patients which had been tested on the day of surgical removal, we did not detect significant correlations between either strip length, weight or calculated cross-sectional area on the one and the magnitude of the KCl response on the other hand (data not shown). A similar picture was also obtained among the strips tested on day 2 (21 strips from 17 patients) or 3 (11 strips from 7 patients). However, if data from all 66 strips (30 patients) from all 3 days were combined, the KCl response was weakly but significantly associated with strip length but not weight or cross-sectional area (Figure 1). Therefore, all further analyses of KCl responses were based on length-adjusted force of contraction (mN/mm).


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)

Role of normalization of contractile responses to 50 mM KCl based upon strip length (upper panel), weight (middle panel), or calculated cross-sectional area (lower panel). Each data represents one strip (in total 66 strips from 30 patients), and data obtained on days 0–2 were included.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Role of normalization of contractile responses to 50 mM KCl based upon strip length (upper panel), weight (middle panel), or calculated cross-sectional area (lower panel). Each data represents one strip (in total 66 strips from 30 patients), and data obtained on days 0–2 were included.
Mentions: We first analyzed how strip size and storage might affect contractile responses to KCl. Using only the 34 strips from 23 patients which had been tested on the day of surgical removal, we did not detect significant correlations between either strip length, weight or calculated cross-sectional area on the one and the magnitude of the KCl response on the other hand (data not shown). A similar picture was also obtained among the strips tested on day 2 (21 strips from 17 patients) or 3 (11 strips from 7 patients). However, if data from all 66 strips (30 patients) from all 3 days were combined, the KCl response was weakly but significantly associated with strip length but not weight or cross-sectional area (Figure 1). Therefore, all further analyses of KCl responses were based on length-adjusted force of contraction (mN/mm).

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