Evidence for a role of prostaglandins in atropine-resistant transmission in the mammalian urinary bladder

It has been known for many years that atropine and other anti-cholinergic drugs readily inhibit the contractile responses of the detrusor portion of the mammalian urinary bladder to exogenous acetylcholine, but only partially inhibit responses to nerve or transmural stimulation (1,2). These findings suggest that the excitatory innervation to the bladder consists not only of cholinergic nerves but also of non-cholinergic nerves. The possibility that such a second excitatory transmitter could be a catecholamine, 5-hydroxytryptamine, bradykinin or histamine has not been supported by experimentation (2). Burnstock, Dumsday and Smythe (3) have presented evidence that ATP might be the second transmitter in the bladder. In the present study we are investigating the role, if any, of prostaglandins in the non-cholinergic responses of urinary bladder to transmural stimulation. For this purpose, we have studied the effects of indomethacin, an inhibitor of prostaglandin synthesis, on responses to transmural stimulation.     

Role of osmotic forces in exocytosis: studies of ADH-induced fusion in toad urinary bladder

Antidiuretic hormone (ADH) treatment of toad urinary bladder activates an exocytotic-like process by which intramembrane particle aggregates are transferred from membranes of elongated cytoplasmic tubules to the luminal-facing plasma membrane. We find that the number of these ADH- induced fusion events, and the number of aggregates appearing in the luminal membrane, are reduced when the luminal bathing medium is made hyperosmotic. As an apparent consequence of the inhibition of their fusion with the luminal membrane, the elongated cytoplasmic tubules become enormously swollen into large, rounded vesicles. These results are consistent with the view that osmotic forces are essential to the basic mechanism of exocytosis.     

Effect of indomethacin on atropine-resistant transmission in rabbit and monkey urinary bladder : Evidence for involvement of prostaglandins in transmission

The effects of 2.9 × 10⁻⁵M atropine and 2.8 × 10⁻⁶M indomethacin on responses of rabbit and monkey detrusor muscle to transmural stimulation were investigated. Responses to transmural stimulation were partially inhibited by atropine. Indomethacin caused further inhibition in the presence of atropine, but did not alter responses to acetylcholine. Prostaglandins E₂ and F_2α contracted rabbit and monkey detrusor. It is suggested that prostaglandins are liberated during stimulation of excitatory nerves to the rabbit and monkey detrusor, and contibute to the resultant contractile response.     

Mouse models of short- and long-term foreign body in the urinary bladder: analogies to the bladder segment of urinary catheters.

Catheter-associated bacteriuria is the most common infection occurring in hospitals, where urethral catheters are generally in place for a few days, and in nursing homes, where catheters may be in place for months or years. We developed murine models with intrabladder urinary catheters for studying complications of bacteriuria in short- and long-term catheterization. In the short-term model, a catheter segment was inserted transurethrally and lay free within the bladder lumen. Half of the animals expelled segments during a 2-to-7-day period, durations similar to catheterizations in hospitalized patients. For studies of long-term catheter use, the catheter segment was secured within the bladder by a single suture for up to 12 months. Antibiotics administered for 7 days after catheter placement and housing mice in cages with wire screen floors reduced spontaneous bacteriuria to an acceptably low incidence rate of only 7%. Proteus mirabilis bacteriuria of high concentration provoked the same complications that are common in patients with long-term catheters: acute pyelonephritis, chronic renal inflammation, and struvite stone formation. These models allow inoculation of the bacteria of interest and are suitable for studies of short- and long-term foreign body-associated bacteriuria and its complications.     

Electric field stimulation alters the outputs of prostaglandins from isolated rat urinary bladder preparations. Influences of papaverine and tetradotoxin

The effects of electric field stimulation (EFS) on the outputs of prostaglandins (PGs) E1, E2 and F2 alpha from isolated contracting rat urinary bladders, were explored. Also, the influences of papaverine (5.10(-6) M) and of tetradotoxin (TTX = 5.10(-7) M) on PGs released by spontaneously contracting or electrically driven preparations, were tested. The basal control outputs of the three PGs in spontaneously contracting urinary bladders, had a comparable magnitude. On the contrary, in electrically stimulated preparations the output of PGE2 rose significantly; that of PGF2 alpha presented a significant reduction and the release of PGE1 was similar to that in controls. Papaverine failed to modify the profile of basal control PG release in non-stimulated bladders, abolished contractile responses to EFS and blocked the augmented output of PGE2 elicited by EFS. The presence of TTX in the suspending solution had no action on the basal control release of PGs from non-stimulated spontaneously contracting preparations, depressed between 80-90% the inotropic responses triggered by EFS and completely antagonized the enhanced output of PGE2 evoked by EFS. Results are discussed in terms of the relative participations of the evoked inotropism of the detrusor muscle or by the stimulation of nerve endings, accounting for the greater release of tissue PGE2 after EFS.     

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.