Increased expression of endothelin B receptors in the diabetic rabbit urinary bladder: functional relevance
Article first published online: 28 JUN 2008
Volume 83, Issue 1, pages 113–122, January 1999
How to Cite
Mumtaz, F.H., Dashwood, M.R., Thompson, C.S., Sullivan, M.E., Mikhailidis, D.P. and Morgan, R.J. (1999), Increased expression of endothelin B receptors in the diabetic rabbit urinary bladder: functional relevance. BJU International, 83: 113–122. doi: 10.1046/j.1464-410x.1999.00897.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- Cited By
- Endothelin A;
- endothelin B;
- urinary bladder;
- diabetes mellitus
To determine the effect of diabetes mellitus on the density and distribution of endothelin A (ETA ) and endothelin B (ETB ) receptor subtypes in the rabbit urinary bladder, and to assess the in vitro functional properties of endothelin-1 (ET-1) receptors in bladder smooth muscle strips from diabetic and healthy rabbits.
Materials and methods
Diabetes mellitus was induced in six male New Zealand White rabbits with alloxan and their urinary bladders excised 6 months after the induction of diabetes. On serial detrusor and bladder neck sections, low- and high-resolution autoradiography was performed using radioligands for ET-1, ETA and ETB receptors; these sections were then analysed densitometrically. The results were compared with those from six age-matched healthy control rabbits. Functional responses were investigated using isometric tension studies.
ETA and ETB receptor binding sites were localized to both the urothelium and smooth muscle of the detrusor and bladder neck. There were significantly more ETB receptor binding sites in the diabetic detrusor and bladder neck sections than in controls. ET-1 smooth muscle contractile responses were ETA receptor-mediated. The smooth muscle contractile responses to ET-1 were unaltered in the detrusor, but significantly impaired in the bladder neck of diabetic animals compared with controls.
Alteration in the expression of ETB receptors and in vitro contractile smooth muscle responses to ET-1 in the diabetic rabbit urinary bladder neck may play a role in the pathophysiology of diabetic cystopathy.