Change of Neuropeptides of Bladder Afferents after Intravesical Electrical Stimulation in Spinalized Rat / 대한비뇨기과학회지

PURPOSE: The clinical benefits of intravesical electrical stimulation (IVES), in patients with increased residual urine or reduced bladder capacity, have been reported. However, studies on the underlying mechanism of IVES have been limited to the Adelta afferent in healthy rats. This study investigated the changes in the calcitonin gene- related peptide (CGRP) and substance P (SP) expressions, in the lumbosacral dorsal root ganglia (DRG) and the bladder of spinalized rats, to determine the effect of IVES on the C fiber afferent nerve. MATERIALS AND METHODS: Forty Sprague-Dawley rats were divided into normal controls (n=10); IVES treated normal rats (n=10); spinalized rats (n=10) and IVES treated spinalized rats (n=10). The IVES was performed for 2 weeks (5 days a week), 3 weeks after the spinalization in the spinalized animals. All animals had their DRG removed at the lumbosacral (L5-S1) level. Changes in the CGRP and SP, at the DRG and bladder, were measured by western-blot analysis. RESULTS: The relative density of the CGRP and SP following spinalization was significantly higher than those in the controls in both the DRG and the bladder. However, IVES in the spinalized rat significantly decreased the relative density of the SP, in both the DRG and the bladder, compared to the rats with spinalization alone. IVES in the spinalized rats significantly decreased the relative density of the CGRP, in the DRG only, compared to the rats with spinalization. CONCLUSIONS: IVES significantly reduced the CGRP and SP levels in the DRG of spinalized rats, but only the SP levels in the bladder. CGRP and SP are the main factors contributing to the hyper-excitability of the micturition reflex following spinal cord injury. These results suggest that the bladder C fiber afferents are also involved in modulating the micturition reflex with IVES.

The Effects of Acute Cystitis on the Sensory Receptors in the Feline Urinary Bladder / 대한마취과학회지

BACKGROUND: Using the urinary bladder as a model, neurophysiological studies of visceral primary afferents supplying inflamed tissue have been studied. In this study we have examined the response of the hypogastric afferents supplying the urinary bladder of the cat to intra-arterially injected algesic chemicals after experimental inflammation. METHODS: Twenty units were recorded from the strands of hypogastric nerve. Once a unit was found, the conduction velocity was determined by extracellular recording of single fiber. When the response of the unit excited by mechanical stimuli was found, chemical stimuli were applied by intra-arterial injection of algesic chemicals (bradykinin, KCl). And then, irritant chemical, 3% mustard oil injected into the urinary bladder for the induction of an experimental inflammation. After removal of the irritant and with the empty bladder, the response of the afferent unit to chemical stimuli by intra-arterially injected bradykinin and KCl were studied again. RESULTS: All units were found to be A delta fibers and responded to both mechanical and chemical stimuli. After experimental inflammation, the basal tone and spontaneous contraction of the urinary bladder were increased and spontaneous nerve activity of the hypogastric afferents appeared. Bladder contraction and nerve activity to intra-arterially injected bradykinin decreased more than those of controls before inflammation. The ratio of nerve activity to the bladder contraction after experimental inflammation was increased. CONCLUSIONS: The hypogastric afferents were sensitized after inflammation, which showed increased nerve response to intra-arterially injected bradykinin comparing to the contraction response of the urinary bladder.

THE SECONDARY AFFERENT PATHWAY OF PELVIC VISCERAL SENSATION / 解剖学报

2?l 10% ricin were injected into the pelvic nerve of cats. After 3～5 survival days 20% HRP solution was injected into the ipsilateral lateral parabrachial nucleus, 2～3 days later the animals were perfused with paraformaldehyde and glutaraldehyde, the brain and spinal cord were removed and processed for light and electron microscopy. It was confirmed that the primary afferent terminals (degenerated) of pelvic nerve formed axo-dendritic and axo-somatic synapses with the retrograde labelled neurons projected to the lateral parabrachial nucleus which were located in the dorsal commissure nucleus (DCN), intermediolateral nucleus (IML) and lamina Ⅰ of sacral spinal cord. Hence, the secondary afferent pathway of pelvic visceral sensation, as. indicated at the ultrastructural level, might originate from DCN, IML and lamina Ⅰ of sacral spinal cord and project to the lateral parabrachial nucleus.

AFFERENT PATHWAY OF THE VAGAL NERVE FIBERS CONVEYING CARDIAC PAIN INFORMATION VIA THE SUPERIOR CERVICAL GANGLION / 解剖学报

Objective To examine the cardiac primary afferents passing through the superior cervical ganglion which the sensory neurons are located in the vagal ganglion. Methods Retrograde tracing transport combined with immunohistochemistry. Results After injecting the horseradish peroxidase(HRP) into the superior cervical ganglion in the rat, the small number of retrogradely labeled neurons consistently appeared in the upper local portion of the nodose ganglion. The same injecting of fluorogold(FG) followed by immunohistochemical staining with SP, it was found that the double\|labeled neurons with FG/SP were approximately 20% occupied the total population of the SP positive neurons in the nodose ganglion. Conclusions The present results, associated with previous reports, suggest that the pathway of the vagal afferent conveying cardiac pain information which contains SP pass through the superior cervical ganglion.\;[