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Vanilloid receptor type 1-immunoreactive nerves in the rat urinary bladder and primary afferent neurones: the effects of age
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Abstract
Indirect immunohistochemistry was used to examine the distribution of nerves immunoreactive (ir) for VR1 in the base of the urinary bladder and in the neurones of the lumbosacral dorsal root ganglia (L1-L2 and L6-S1) of young adult (3 months) and aged (24 months) male rats. Semi-quantitative estimations of nerve densities were assessed and quantitative studies were also used to examine the effects of age on the percentage of VR1-ir dorsal root ganglion neurones. The bladder base in young adults showed dense VR1-ir fibres within the urothelium and in the subepithelium and fibres ranging from sparse to moderate in number in the muscle coat. In comparison to the young animals, the aged rats showed sparse to moderate densities of VR1-ir nerves in the subepithelium and sparse fibres in the muscle layers. In the lumbosacral dorsal root ganglia the percentage of VR1-ir neuronal profiles showed a significant reduction from (mean ± SEM) 17.8 ± 2% in the young adult to 12 ± 1.6 in the aged rats. The present findings suggest that the effects of VR1 on bladder function (nociception and reflex micturition) are influenced by age and the reduction with age of VR1-ir neurones in the dorsal root ganglia could also have important implications for the micturition reflex.
Abstract
Indirect immunohistochemistry was used to examine the distribution of nerves immunoreactive (ir) for VR1 in the base of the urinary bladder and in the neurones of the lumbosacral dorsal root ganglia (L1-L2 and L6-S1) of young adult (3 months) and aged (24 months) male rats. Semi-quantitative estimations of nerve densities were assessed and quantitative studies were also used to examine the effects of age on the percentage of VR1-ir dorsal root ganglion neurones. The bladder base in young adults showed dense VR1-ir fibres within the urothelium and in the subepithelium and fibres ranging from sparse to moderate in number in the muscle coat. In comparison to the young animals, the aged rats showed sparse to moderate densities of VR1-ir nerves in the subepithelium and sparse fibres in the muscle layers. In the lumbosacral dorsal root ganglia the percentage of VR1-ir neuronal profiles showed a significant reduction from (mean ± SEM) 17.8 ± 2% in the young adult to 12 ± 1.6 in the aged rats. The present findings suggest that the effects of VR1 on bladder function (nociception and reflex micturition) are influenced by age and the reduction with age of VR1-ir neurones in the dorsal root ganglia could also have important implications for the micturition reflex.
Keywords
VR1; immunohistochemistry; sensory neurones; dorsal root ganglia
Title
Vanilloid receptor type 1-immunoreactive nerves in the rat urinary bladder and primary afferent neurones: the effects of age
Journal
Issue
Article type
Original article
Pages
213-220
Published online
2006-06-08
Page views
584
Article views/downloads
946
Bibliographic record
Folia Morphol 2006;65(3):213-220.
Keywords
VR1
immunohistochemistry
sensory neurones
dorsal root ganglia
Authors
H.A.M. Saleh