Premium
Comparison of relaxation responses of detrusor strips from neuropathic and control patients
Author(s) -
WILLIAMS P.,
DATTA S.,
GERMAN K.,
STEPHENSON T.P.,
BEDWANI J.R.
Publication year - 1995
Publication title -
british journal of urology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 0007-1331
DOI - 10.1111/j.1464-410x.1995.tb00764.x
Subject(s) - guanethidine , stimulation , relaxation (psychology) , chemistry , anesthesia , sodium nitroprusside , nitric oxide , medicine , endocrinology
Objectives To confirm the existence of relaxation responses to electrical‐field stimulation in strips of human detrusor, and to compare these responses in strips from control subjects with those in strips from a group of neuropathic patients exhibiting hyper‐reflexia. Patients and methods Detrusor specimens were obtained at operation from a group of control patients, and from a group of patients with neuropathy (mainly spina bifida) and a history of hyper‐reflexia. Muscle strips were prepared from these, mounted in organ baths, and contracted by exposure to a modified Krebs' solution containing 26 m m KCl and atropine. Relaxation responses were induced by an electrical‐field stimulation (50 V, 90 μs pulses at 2–16 Hz for 10 s). Results Of 29 strips, 20 (69%) from control patients showed relaxations, compared with 17 of 28 strips (61 %) from neuropathic patients ( P > 0.1). The maximum relaxation response in the control strips was 49 ± 5.6% (mean ± sem ) of the maximum relaxation induced by isobutyl methylxanthine, compared with 43 ± 4.8% in the strips from neuropathic patients ( P > 0.1). The maximum response occurred at similar frequencies (4 or 8 Hz) in the two groups. The relaxations were reduced by the inhibitor of nitric oxide synthase, N‐nitro L‐arginine methyl ester (0.1 m m , P < 0.05), but were not affected by guanethidine (50 μ m ) or tetrodotoxin (0.5 μ m ). Conclusion These results confirm the existence of field stimulation‐induced relaxation in human detrusor, but suggest that hyper‐reflexia in the neuropathic bladder cannot be accounted for by any deficiency in this response.