Structural and functional relations between the connective tissue and epithelium of enamel organ and their role during enamel maturation.

The morphological and possible functional interactions between the connective tissue and enamel organ cells were examined during the maturation phase of enamel formation, using immunohistochemical techniques. Decalcified mandibular sections (10 µm) including incisors were used from Wistar rats ages 10-12 weeks. Sections were incubated with one or two primary antibodies targeting cell cytoskeleton (vimentin, α-actin, α-tubulin), dendritic marker (OX6), gap junctions (cx-43), enzymes (nitric-oxide synthase (nos1) and cyclooxygenase (cox1)), and the ion transporters (Na/H exchanger (NHE1) and Na/Ca exchanger (NCX)) for 24 h, before incubation with the appropriate conjugated fluorescent secondary antibodies.

The actions of prolonged exposure to cholinergic agonists on isolated bladder strips from the rat.

The present study was done to explore the cholinergic systems operating in the wall of the isolated rat bladder. In a first set of experiments, bladder strips in vitro were subjected to cumulative concentration-response curve (CRC) to non-selective muscarine agonist carbachol or the partially M2>M3 selective agonist arecaidine to establish optimal concentration to be used thereafter. In a second set of experiments, the effects of drugs (solifenacin, isoproterenol, and mirabegron) were tested on urinary bladder contraction induced by the non-selective muscarinergic agonist carbachol.

The concept of peripheral modulation of bladder sensation.

It is recognized that, as the bladder fills, there is a corresponding increase in sensation. This awareness of the volume in the bladder is then used in a complex decision making process to determine if there is a need to void. It is also part of everyday experience that, when the bladder is full and sensations strong, these sensations can be suppressed and the desire to void postponed.

"Focused introspection" during naturally increased diuresis: description and repeatability of a method to study bladder sensation non-invasively.

Objective: To present and describe a non-invasive method to study the origin and development of bladder filling sensation and to evaluate the repeatability of the method.

Method: Eighteen volunteers participated in the study and were given a water loading protocol consisting of 1,000 ml water intake 1 hr before the session and 200 ml every 10 min during the session. Protocol 1: To evaluate diuresis rate, seven participants were asked to void every 15 min and the voided volume was measured.

Modulation of non-voiding activity by the muscarinergic antagonist tolterodine and the β(3)-adrenoceptor agonist mirabegron in conscious rats with partial outflow obstruction.

Unlabelled: Experimental urethral obstruction in rats alters micturition patterns with non-voiding activity (NVA) during filling cystometry, showing similarity to that observed in human detrusor overactivity. Several drug classes with therapeutic potential in overactive bladder in humans have been tested in this model in rats, rabbits or guinea pigs, but no detailed analysis of drug effects on cystometric patterns has been published. The present study uses a rat model of overactivity with partial bladder outflow obstruction (BOO) in combination with the procedures to analyse NVA to study the effects of the anticholinergic drug tolterodine and the novel β(3)-adrenoceptor agonist mirabegron.

Nonvoiding activity of the guinea pig bladder.

Purpose: Detrusor nonvoiding contractions occur in up to 70% of healthy individuals. These contractions increase in those with pathological detrusor function and may be associated with afferent activity. We examined nonvoiding contractions in the urethane anesthetized guinea pig bladder and studied the effect of filling rate and intravesical volume.

M3 muscarinic receptor-like immunoreactivity in sham operated and obstructed guinea pig bladders.

Purpose: Type 3 muscarinic receptors, which are present in the bladder wall, are important for bladder function. However, their role in the context of the urothelium is not well defined. Understanding the role of type 3 muscarinic receptors has been limited by the lack of specific type 3 muscarinic receptor antibodies.

The relationship between prostaglandin E receptor 1 and cyclooxygenase I expression in guinea pig bladder interstitial cells: proposition of a signal propagation system.

Purpose: We explored the structural relationship between enzymes producing prostaglandin (cyclooxygenase I) and 1 of the receptor families that respond to prostaglandin (prostaglandin E receptor 1) in the bladder muscle.

Materials And Methods: Nine male guinea pigs were sacrificed by cervical dislocation. Bladders were removed and fixed in 4% paraformaldehyde in phosphate buffered saline.

Prostaglandin receptor EP1 and EP2 site in guinea pig bladder urothelium and lamina propria.

Purpose: Urothelium has 2 main functions. It is a barrier to urine and has a sensory role. In response to stretch urothelium releases various substances that modulate afferent nerve activity.

Stretch independent regulation of prostaglandin E(2) production within the isolated guinea-pig lamina propria.

Objective: To use an isolated preparation of the guinea-pig bladder lamina propria (LP) to investigate the effects of adenosine tri-phosphate (ATP) and nitric oxide (NO) on the release of prostaglandin E(2) (PGE(2)).

Materials And Methods: The bladders of female guinea-pigs (200-400 g) were isolated and opened to expose the urothelial surface. The LP was dissected free of the underlying detrusor muscle and cut into strips from the dome to base.

On the origins of the sensory output from the bladder: the concept of afferent noise.

For many people a recurrent strong desire to void, sometimes with incontinence, diminishes their quality of life. At present there are few insights into what underlies these problems. The condition is described as the 'overactive bladder symptom complex' but this definition is proving to be unhelpful.

M(3) muscarinic receptor expression on suburothelial interstitial cells.

Objective: To identify the cells expressing the M(3) muscarinic receptor subtype in the lamina propria of the bladder.

Materials And Methods: The bladders from five normal guinea pigs were isolated and fixed in 4% paraformaldehyde. Tissues sections (10 microm) were then cut and stained with antibodies to the type 3 muscarinic receptor (M(3)), the interstitial cell marker vimentin and the nonspecific nerve marker PGP 9.

Ubiquitin hydrolase (protein gene product 9.5) in the obstructed bladder: evidence for tissue remodelling involving a subset of interstitial cells.

Objective: To examine the expression of ubiquitin hydrolase (UH), an enzyme which is part of the ubiquitin-proteasome system involved in the regulation of cell growth and differentiation, to gain an insight into the cell types and processes underlying the tissue remodelling that occur after bladder neck damage.

Materials And Methods: Three groups of male guinea pigs were used, comprising controls (not operated, four), sham (five) and obstructed (six). The bladder outlet was obstructed by implanting a silver ring around the urethra, which was left in situ for 2-4 weeks.

Volume-induced responses in the isolated bladder: evidence for excitatory and inhibitory elements.

Objective: To quantify changes in autonomous activity in response to alterations in intravesical volume, to explore the possible underlying regulatory mechanisms.

Materials And Methods: Experiments were conducted using whole isolated bladders from six female guinea pigs (280-400 g). A cannula was inserted into the urethra to monitor intravesical pressure and the bladder was suspended in a heated chamber containing carboxygenated physiological solution at 33-36 degrees C.

Regional differences in sensory innervation and suburothelial interstitial cells in the bladder neck and urethra.

Objective: To identify and characterize possible structural specialisations in the wall of the lower urinary tract (LUT) in the region of the bladder urethral junction (BUJ), with the specific objective of identifying regional variations in sensory nerve fibres and interstitial cells (ICs).

Materials And Methods: The bladder base and urethra was removed from five male guinea pigs killed by cervical dislocation. Tissue pieces were incubated in Krebs' solution at 36 degrees C, gassed with 95% O(2) and 5% CO(2), fixed in 4% paraformaldehyde and processed for immunohistochemistry.

Damage to the bladder neck alters autonomous activity and its sensitivity to cholinergic agonists.

Objective: To identify and describe changes to the motor component of the motor/sensory system, which contributes to sensation during the filling phase of the micturition cycle, as a result of surgically induced bladder pathology, i.e. damage to the bladder neck and outlet obstruction.

Cholinergic activation of phasic activity in the isolated bladder: possible evidence for M3- and M2-dependent components of a motor/sensory system.

Objectives: To analyse pressure changes induced by muscarinic agonists on the isolated bladder in order to examine whether there are different responses representing different components of a motor/sensory system within the bladder wall.

Materials And Methods: Whole isolated bladders from 19 female guinea-pigs (280-400 g) were used. A cannula was inserted into the urethra to monitor intravesical pressure and the bladder was suspended in a heated chamber containing carboxygenated physiological solution at 33-36 degrees C.

The effects of exogenous prostaglandins and the identification of constitutive cyclooxygenase I and II immunoreactivity in the normal guinea pig bladder.

Objectives: To establish the functional consequences of exposing the isolated whole bladder preparation to exogenous prostaglandins (PGE(1), PGE(2), PGF(2alpha)) and to determine which cells express cyclooxygenase (COX) types I and II, to generate PG to effect these changes in vivo.

Materials And Methods: Fifteen female guinea pigs (270-350 g) were used, i.e.

Interstitial cells and phasic activity in the isolated mouse bladder.

Objective: To describe the distribution of interstitial cells (ICs, defined as cells which show an increase in cGMP in response to nitric oxide, NO) in the isolated mouse bladder, and changes in phasic contractile activity after exposure to a NO donor.

Materials And Methods: The whole bladder was removed from 17 female mice, killed by cervical dislocation. For immunohistochemistry (six mice) the bladder was incubated in carboxygenated Krebs' solution at 36 degrees C, containing 1 mm of the phosphodiesterase inhibitor isobutyl-methyl-xanthine.

Antimuscarinic drugs in detrusor overactivity and the overactive bladder syndrome: motor or sensory actions?

Antimuscarinic drugs are generally thought to exert their therapeutic action on detrusor overactivity by reducing the ability of the detrusor muscle to contract. We review currently available published data to establish whether there is any evidence to support this contention. Using a PubMed data search, only 14 original articles (including two abstracts) were found that contained cystometric data for both filling and voiding phases and where the actions of antimuscarinic drugs have been reported in detail.

Location of interstitial cells and neurotransmitters in the mouse bladder.

Introduction: To investigate whether interstitial cells (ICs) are present in the adult mouse bladder, and what transmitters characterize adjacent nerve fibres, as ICs in human and guinea-pig bladder lie close to nerve fibres but transmitters present in these nerves have not yet been reported.

Materials And Methods: Sections of the bladder wall from 12 adult male mice (six each, aged 3-4 or 18-24 months) were incubated in carboxygenated Krebs' solution containing isobutyl-methyl-xanthene (1 mm), followed by the nitric oxide (NO) donor diethylamino-NONOate; control tissues remained in Krebs' solution. Samples were fixed in 4% paraformaldehyde and processed for immunofluorescence histochemistry for cGMP, neuronal NO synthase (nNOS), vesicular acetylcholine transferase (VAChT), calcitonin gene-related polypeptide (CGRP) and protein gene product (PGP) 9.

Phasic non-micturition contractions in the bladder of the anaesthetized and awake rat.

Objective: To characterize the contractile activity that occurs in the bladder during the filling phase of the micturition cycle (non-micturition contractions, NMCs), which generate transient rises in intravesical pressure not associated with urine flow.

Materials And Methods: The experiments were conducted using anaesthetized (chloral hydrate) and un-anaesthetized rats. In un-anaesthetized rats bladder contractile activity was measured using an intravesical cannula implanted under full surgical anaesthesia 3 days previously.

Interstitial cells and cholinergic signalling in the outer muscle layers of the guinea-pig bladder.

Objectives: To explore the relationship between cholinergic mechanisms and interstitial cells (ICs) in the outer muscle layer of the bladder.

Materials And Methods: In bladder tissue from male guinea-pigs, ICs were identified by their response to nitric oxide (NO) with a rise in cGMP. Sections of the lateral bladder wall were incubated in Krebs' solution containing 1 mm of the nonspecific phosphodiesterase inhibitor isobutyl-methyl-xanthene.

Bladder volume alters cholinergic responses of the isolated whole mouse bladder.

Purpose: The isolated bladder expresses autonomous activity, which may contribute to the generation of lower urinary tract sensation or pathophysiology. We evaluated how the effect of a cholinergic agonist on autonomous activity alters with increasing volume and in the presence of substances known to modulate functional bladder capacity.

Materials And Methods: The bladder of 22 adult female C57 black mice were mounted in whole organ tissue baths.

A developing view of the origins of urgency: the importance of animal models.

Although caution should be used when applying animal data to human physiology, if care is taken to differentiate between general principles and complications of detail, particular to the species being examined, then experimentation on animal models can reveal basic phenomena in the bladder that offer clues to the origin of urgency. Recent data from the whole isolated bladder of guinea pigs showed unexpected complexities in autonomous activity during the filling phase of the micturition cycle: small, transient increases in intravesical pressure were associated with propagating waves of contractile activity and localized stretches of bladder wall. This complex, coordinated activity suggests that there are mechanisms within the bladder wall devoted specifically to generating phasic activity.