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Contractile properties of the developing fetal sheep bladder
Author(s) -
Nyirády Peter,
Thiruchelvam Nikesh,
Godley Margaret L.,
David Anna,
Cuckow Peter M.,
Fry Christopher H.
Publication year - 2005
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.20124
Subject(s) - carbachol , isometric exercise , medicine , fetus , endocrinology , gestational age , gestation , muscle contracture , stimulation , detrusor muscle , contractility , urinary bladder , pregnancy , anatomy , biology , genetics
Aim To characterise the developmental changes to the normal bladder by examining the in vitro contractile properties of the fetal sheep detrusor smooth muscle bladder at different gestational ages. Methods Three groups of normally developing fetal sheep bladders were investigated: (1) 65–70 days gestation (2nd trimester); (2) 105–110days (3rd trimester); (3) 135–140 days (term). Isometric contractions in isolated detrusor strips were measured during either electrical field stimulation (EFS) or exposure to agonists: carbachol, α‐β methylene‐ATP (ABMA) and KCl. Results There was a significant increase of absolute force elicited by EFS with fetal age. Contractures elicited by carbachol, ABMA and KCl increased between Groups 1 and 2, but not thereafter. The proportional increase of contractions elicited by carbachol and ABMA was also greater between Groups 1 and 2, than for EFS and KCl. Conclusions Fetal development between 65 and 140 days in the sheep is associated with increased contractile activation. The data are consistent with an increase of muscle development in the earlier stages (65–110 days). In the later stage (110–140 days) muscle development is complete but functional innervation of the tissue continues. © 2005 Wiley‐Liss, Inc.