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Cystometric and in vitro muscle studies of cystoplastic appendiceal segments in the rat
Author(s) -
Semerdzhiev Yavor,
Frederiksen Hans,
Hedlund Petter,
Davidsson Thomas,
Mansson Wiking,
Uvelius Bengt
Publication year - 2006
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.20155
Subject(s) - cystometry , medicine , urination , detrusor muscle , carbachol , urinary bladder , urology , stimulation , muscle contraction , anesthesia , anatomy , urinary system , endocrinology
Abstract Aims The functional integration of the smooth muscle of enterocystoplasties into the detrusor muscle was investigated in an awake‐rat cystometry model and in vitro. Methods The upper fourth of the bladder was removed, and a detubularized appendiceal segment (7 × 7 mm), with preserved vasculature, was incorporated into the bladder. After 1 or 3 months, a catheter was fixed to the top of the bladders. After a 3‐day recovery, cystometries were performed. In separate experiments, agonist and nerve‐induced responses were evaluated on isolated bladder strips. Results Cystometries revealed reduced basal pressure and micturition pressure in enterocystoplasty (ECP) bladders. Bladder capacity and micturition volume were increased. Threshold pressure (pressure immediately before micturition) was significantly lower at 1 month, but not at 3 months. Bladder compliance was significantly higher in the operated at 1 month but not at 3 months. Threshold tension did not differ between control and corresponding operated groups. Residual urine was significantly higher in the operated groups. ECP strips showed increased maximal contractions to nerve stimulation, to levels similar to those of detrusor strips. Maximal responses to carbachol increased to levels between those of intestine and detrusor. The inhibitory effect of scopolamine on nerve induced contractions increased to levels similar to those for detrusor. Purinergic activation had no effect on intestinal or ECP strips, but contracted detrusor muscle. Conclusions The smooth muscle of the bowel segment in rat ECP bladders underwent a partial change in the response to nerve stimulation from that of intestine towards that of detrusor. The cystometry experiments suggested a partial functional integration of the ECP segment into the detrusor. Neurourol. Urodynam. 25:259–267, 2006. © 2006 Wiley‐Liss, Inc.