Venous drainage of the urinary bladder

The venous drainage of the urinary bladder was studied in 20 pelvic halves (14 males and 6 females). Vesical and prostatic plexuses draining the bladder (vesical only in females) were found in 16 cases; they supplied blood to the internal iliac vein--usually by two to five veins--the most common number being three. One vein always drained the prostatic plexus. The vesical and prostatic plexuses were absent in 4 male cases, where the vesical veins issuing from the bladder wall drained directly the internal iliac vein. Their number in such cases was minimal: between one and two only, on each side. The union of a vesical vein issuing from any of the two mentioned plexuses (when found) with the obturator, prostatic or vaginal vein was common. A shunt from a common trunk of united obturator and vesical veins to the external iliac vein was noticed in some cases. Occasionally, an inferior vesical vein ending in the obturator vein accompanied an inferior vesical artery initiating from the obturator artery.     

Diverticulum of the urinary bladder in a woman

In the two cases of congenital absence of the vagina reported herein, the embryologic point of arrest of development of the mullerian ducts was identical. Both patients had a rudimentary uterus, and one had a fibroid tumor on the rudimentary uterus. As a part of operation to construct a vagina in such cases, exploratory pelvic laparotomy appears to be a desirable step in order to determine the status of the internal genital organs. The use of a split thickness skin graft sewn around a vaginal mold and inserted into the dissected vaginal space results in more rapid healing, less scar tissue and a vagina that is soft, pliable and normal in appearance, even to the extent of having rugal folds.     

Intramural neurons in the urinary bladder of the guinea-pig

Summary The urinary bladder of adult female guinea-pigs was stained histochemically to detect the presence of intramural ganglion neurons. Counts on wholemount preparations of entire bladders revealed the presence of 2000–2500 neurons per bladder, either as individual nerve cells or, more often, as ganglia containing up to 40 neurons. Both ganglia and single neurons lie along nerve trunks and are interconnected to form a plexus. Ganglia occur in every part of the bladder; they are more numerous on the dorsal than on the ventral wall, and they are especially abundant in an area within a radius of 800 m from the point of entry into the bladder wall of ureters and urinary arteries. The ganglia are located inside the muscle coat and close to muscle bundles; they usually lie nearer the mucosa than the serosa. Ultrastructurally, each ganglion is surrounded by a capsule; in addition to neurons and glial cells, the ganglia contain capillaries, collagen fibrils and fibroblasts; ganglion neurons are individually wrapped by glial cells and are separated from one another by connective tissue.     

Inhibitory beta-adrenoceptors in the urinary bladder of the rat

The β-adrenoceptors of the urinary bladder were investigated in the rat $\text{in}$$\text{vivo}$. Isoprenaline, and the β₂-stimulating agents terbutaline and salbutamol elicited relaxation of the detrusor muscle decreasing the intravesical pressure. The responses were not affected by the β₁-blocking agents practolol or H 93/26 but were totally abolished by propranolol and the β₂-blocking agent H $\text{35}\text{25}$. Noradrenaline given after dihydro-ergotamine caused relaxation of the detrusor muscle and this response was completely blocked by propranolol and H $\text{35}\text{25}$. It is concluded that the β-adrenoceptors of the rat urinary bladder belong to the type of inhibitory receptors classified as β₂-receptors in other organs.     

Structure of the urinary bladder in the Pacific cod

The urinary bladder of the Pacific cod,Gadus macrocephalus was investigated. A pair of ureters was found to unite and form a sac-like protrusion on the posteroventral aspect of the gonad. This protrusion was confirmed as the urinary bladder based on its histology and the presence of ammonia and urea in the fluid within this structure. The urinary bladder consisted of a central lumen and two lateral expansions found on the right and left sections. The luminal epithelial cells of the Pacific cod urinary bladder, unlike those of other animals, were characterized by microvilli on the free surface, and the presence of a number of vesicles and mitochondria across the apical portion on the cells. This suggests that the luminal epithelium of the urinary bladder might be actively engaged in transportation of water or other materials from the urine. The Pacific cod urinary bladder may therefore be closely associated with osmoregulation by reabsorbing water from the urine. Ammonia-N and urea-N levels of 65–213 μg/dl and 1.5–3.5 mg/dl were measured in the fluid which filled the urinary bladder.     

Molecular mechanisms in urinary bladder carcinogenesis

Urinary bladder cancer accounts for approximately 5% of all newly diagnosed malignancies in the developed world. Smoking, occupational exposure and dietary factors constitute the most important exogenous risk factors for bladder carcinogenesis. Yet, individuals with seemingly equal exposure to environmental carcinogens develop bladder cancer in an unpredictable manner. This is probably attributed to the fact that DNA repair capacity varies in human populations, pointing the role of genetic susceptibility in human cancer. Numerous studies demonstrated that certain genetic and epigenetic alterations are fairly constant. Loss of heterozygosity (LOH) at chromosome 9 is an aberration found in urothelial cell carcinoma (UCC) of all stages and grades as well as in dysplastic urothelium, possibly representing an early event in urinary bladder carcinogenesis. On the contrary, gains of 3p can only be found in tumors demonstrating highly malignant behavior. Microsatellite instability (MSI) is another frequent finding in urinary bladder cancer. This has led many investigator groups to employ the analysis for MSI for early diagnosis of UCC with promising results. The silencing of certain genes such as p16(INK4A) and DAPK by aberrant methylation of their promoter region also represents an important mechanism in carcinogenesis. Similarly, alterations in certain tumor suppressor genes and proto-oncogenes result in uncontrolled cell proliferation, reduced apoptosis and have been associated with more aggressive UCC phenotypes. Undoubtedly, the application of these observations in clinical practice will make a breakthrough in the management of bladder cancer.     

Telocytes subtypes in human urinary bladder

Urinary bladder voiding is a complex mechanism depending upon interplay among detrusor, urothelium, sensory and motor neurons and connective tissue cells. The identity of some of the latter cells is still controversial. We presently attempted to clarify their phenotype(s) in the human urinary bladder by transmission electron microscopy (TEM) and immunohistochemistry. At this latter aim, we used CD34, PDGFRα, αSMA, c‐Kit and calreticulin antibodies. Both, TEM and immunohistochemistry, showed cells that, sharing several telocyte (TC) characteristics, we identified as TC; these cells, however, differed from each other in some ultrastructural features and immunolabelling according to their location. PDGFRα/calret‐positive, CD34/c‐Kit‐negative TC were located in the sub‐urothelium and distinct in two subtypes whether, similarly to myofibroblasts, they were αSMA‐positive and had attachment plaques. The sub‐urothelial TC formed a mixed network with myofibroblasts and were close to numerous nerve endings, many of which nNOS‐positive. A third TC subtype, PDGFRα/αSMA/c‐Kit‐negative, CD34/calret‐positive, ultrastructurally typical, was located in the submucosa and detrusor. Briefly, in the human bladder, we found three TC subtypes. Each subtype likely forms a network building a 3‐D scaffold able to follow the bladder wall distension and relaxation and avoiding anomalous wall deformation. The TC located in the sub‐urothelium, a region considered a sort of sensory system for the micturition reflex, as forming a network with myofibroblasts, possessing specialized junctions with extracellular matrix and being close to nerve endings, might have a role in bladder reflexes. In conclusions, the urinary bladder contains peculiar TC able to adapt their morphology to the organ activity.     

Ion channels in urinary bladder.

Urinary epithelia separate urine from interstitial fluid. In the mammal, this tight epithelium has a limited transport capacity but is capable of moving sodium from urine to blood through an aldosterone-sensitive cellular pathway. In lower vertebrates, absorption of ions and water from the urine can contribute significantly to fluid and electrolyte homeostasis. Transepithelial ion transport and maintenance of cellular composition are interdependent, requiring a balance between movements across the apical and basolateral plasma membranes through a variety of pathways including electrodiffusion through ion channels. A variety of such channels has been identified in urinary epithelia. Apical membranes contain amiloride-sensitive, highly selective sodium channels of low conductance (approximately 5-10 pS). There is evidence that in mammalian bladders trypsin-like enzymes in the urine continually degrade these channels, decrease in cation selectivity being followed by loss of the channels from the membrane. New channels stored in the cytoplasm appear to provide a source for replenishment of the membrane. Other channels of higher conductance and lower selectivity have also been described in both mammalian and amphibian bladders, but their physiological significance remains to be established. Basolateral membranes contain potassium channels. In the mammalian bladder, in which chloride appears to be distributed at electrochemical equilibrium, chloride conductance exceeds potassium conductance and patch clamp studies have revealed a chloride channel of conductance approximately 60 pS detectable immediately on patch excision and active at normal membrane potentials. In the amphibian bladder, a variety of findings indicates the presence of a basolateral membrane chloride conductance, but patch clamp data are not yet available.