Effect of choline ester analogues, noradrenaline and nifedipine on normal and hypertrophied human urinary bladder detrusor muscle.

1. Acetylcholine, bethanechol, carbachol and propionylcholine were all agonists of normal human detrusor smooth muscle. The order of potency was found to be carbachol > acetylcholine > bethanachol > propionylcholine. 2. In hypertrophied detrusor smooth muscle carbachol was more potent than acetylcholine, but hypertrophied detrusor preparations were less sensitive to carbachol than normal detrusor smooth muscle. 3. Noradrenaline had no direct effect on either normal or hypertrophied detrusor muscle, but it had a reversible inhibitory effect on the spontaneous contractile activity of normal detrusor preparations. Hypertrophied detrusor preparations usually lacked such spontaneous activity. 4. In calcium-free saline, agonist-induced responses of both normal and hypertrophied detrusor muscle were dramatically reduced indicating that choline ester activity in the muscles was strongly dependent upon extracellular calcium. 5. Nifedipine at 10(-5) mol l-1 inhibited acetylcholine responses and K(+)-induced contractures of both normal and hypertrophied detrusor muscles. Acetylcholine-induced responses of normal detrusor preparations were much more sensitive to inhibition by nifedipine than were the responses of hypertrophied detrusor muscle. 6. The properties and densities of both the muscarinic cholinoreceptors and calcium channels appear to have been altered by the hypertrophic response secondary to benign prostatic hyperplasia.

Purinergic modulation of rat urinary bladder detrusor smooth muscle.

1. Rat detrusor muscle was responsive to both ATP and adenosine; ATP elicited an excitatory response, whereas adenosine had an inhibitory effect. 2. ATP and adenosine had an inhibitory modulatory action on responses to acetylcholine, potassium depolarization and field stimulation. 3. Quinidine inhibited the ATP response and blocked the inhibitory effect of ATP on acetylcholine, potassium-depolarization and field-stimulation responses. The effect of adenosine remained unaltered in the presence of quinidine. 4. Caffeine and theophylline blocked the adenosine inhibition of responses to field stimulation. 5. It is concluded that excitatory P2-type purinoreceptors mediated by ATP and inhibitory P1-type purinoreceptors mediated by adenosine exist in rat urinary bladder detrusor smooth muscle and that both ATP and adenosine exhibit a modulatory action on detrusor muscle agonist-induced responses.

Electrolyte homeostasis in urothelial neoplasia: the effects of amiloride.

OBJECTIVE: To investigate the effect of amiloride preincubation on the intracellular electrolyte levels in neoplastic and non-neoplastic urothelium. MATERIALS AND METHODS: Samples of papillary transitional cell carcinomas (grades 1 and 2) and non-neoplastic human urothelium were either frozen immediately or after pre-incubation with Krebs saline alone or with Krebs saline containing amiloride. The frozen samples were planed in a cryo-ultramicrotome and then examined by low temperature scanning electron microscopy. Intracellular electrolyte levels were measured using X-ray microanalysis. RESULTS: In the cells frozen immediately the ratios K+/Na+, K+/P and K+/Cl- were significantly increased in neoplastic compared with non-neoplastic urothelial cells (P < 0.001). This difference was also found in the cells pre-incubated with Krebs saline alone but was not present in the cells pre-incubated with amiloride. CONCLUSIONS: These results were consistent with the concept that activation of the amiloride-sensitive Na+/H+ membrane exchanger is a primary event in neoplasia.

Electrolyte levels in neoplastic and nonneoplastic human urothelium after ouabain treatment: X-ray microanalysis of bulk hydrated samples.

Samples of neoplastic and nonneoplastic human urothelium were immediately frozen, incubated in Krebs' saline and then frozen, or incubated in 10(-5) mol/L ouabain in Krebs' saline and then frozen. The frozen specimens were then planed in a cryoultramicrotome and examined by low-temperature scanning electron microscopy. X-Ray microanalysis was performed on the superficial urothelial cells. Neoplastic cells immediately frozen and those incubated in Krebs' saline had significantly higher K+/Na+, K+/P, and K+/Cl- ratios and lower Na+/P and Cl-/P ratios than nonneoplastic cells. Incubation in ouabain led to a fall in the K+/Na+, K+/P, and K+/Cl- ratios and a rise in the Na+/P and Na+/Cl- ratios in both neoplastic and non-neoplastic cells and effectively nullified the difference between them. These results are consistent with the concept that in neoplasia a primary event is stimulation of Na+/H+ exchange, which leads to secondary stimulation of the ouabain-sensitive Na+/K+ ATPase pump.

X-ray microanalysis of bulk hydrated specimens of neoplastic and non-neoplastic human urothelium.

Specimens of neoplastic and non-neoplastic human urothelium were rapidly frozen against a copper block immersed in liquid nitrogen, planed in a cryoultramicrotome and then examined by low-temperature scanning electron microscopy (LTSEM) following coating by aluminium. Energy dispersive X-ray microanalysis (XRMA) was performed on the superficial urothelial cells and on gelatin blocks mounted in parallel which had known concentrations of sodium, potassium, chloride, and phosphorus. The neoplastic urothelial cells had significantly less phosphorus (P less than 0.05) than non-neoplastic cells and the ratios K+/P,K+/Na+, and K+/Cl- were significantly higher in neoplastic cells than in non-neoplastic cells (P less than 0.00001). These results are consistent with those expected in cells with a sustained increase in intracellular pH caused by stimulation of Na+/H+ ion membrane exchange.

Low-temperature and conventional scanning electron microscopy of human urothelial neoplasms.

The appearance of neoplastic human urothelium viewed by low-temperature scanning electron microscopy (LTSEM) and conventional scanning electron microscopy (CSEM) was compared. Fixed, dehydrated neoplastic cells viewed by CSEM had well-defined, often raised cell junctions; no intercellular gaps; and varying degrees of pleomorphic surface microvilli. The frozen hydrated material viewed by LTSEM, however, was quite different. The cells had a flat or dimpled surface, but no microvilli. There were labyrinthine lateral processes which interdigitated with those of adjacent cells and outlined large intercellular gaps. The process of fixation and dehydration will inevitably distort cell contours and on theoretical grounds, the images of frozen hydrated material should more closely resemble the in vivo appearance.

Quantitative X-ray microanalysis of bulk hydrated specimens: a method using gelatine standards.

A method of preparing and using gelatine blocks as standards for quantitative X-ray microanalysis of bulk hydrated tissue is described. Each series of standards had several constant and one variable element. The average deviations in the X-ray counts of the constant elements from the series means were used to correct the recorded count of the variable element in each block. This led to an improved linear relationship between X-ray counts and concentration. The elements tested, sodium, phosphorus, and potassium, were chosen as representatives of different parts of the X-ray spectrum. Sodium cannot be measured reliably below 50 mmol kg-1 wet weight, although phosphorus and potassium can be detected at concentrations of 5 mmol kg-1 wet weight. It is argued that this sensitivity of analysis is sufficient for studying electrolyte changes in certain pathological processes.

DIDMOAD syndrome with megacystis and megaureter.

A case of DIDMOAD syndrome (diabetes insipidus, diabetes mellitus, optic atrophy and nerve deafness) is described. There was unusually severe urinary tract dilatation which led to an ileal conduit diversion. Immunohistological study of the bladder wall and ureter revealed a marked diminution in nerve fibres, which may have been primary or secondary to the muscle hypertrophy. The possible pathogenesis of the urinary tract dilatation is discussed in relation to this finding.

Scanning electron microscopy of adenomatoid tumours.

Four adenomatoid tumours of the epididymis were embedded in paraffin wax, sectioned and the sectioned surfaces examined by scanning electron microscopy using the secondary electron mode. The solid faces of the sectioned neoplasms were damaged by the preparative technique but the depressed luminal surfaces of the tubules were well preserved and yielded useful information. Large areas of luminal surface were examined and the presence and distribution of microvilli were noted. In addition, there was a more complex cell surface pattern of intersecting cord-like elevations. Desquamating cells were seen within the tubules and the cytoplasmic bridges noted by light microscopy were shown to be thin cytoplasmic partitions. These findings are consistent with the mesothelial theory of histogenesis. Scanning electron microscopy can provide useful information about the internal structure of neoplasms even with simple preparative techniques.

Low temperature and conventional scanning electron microscopy of human urothelium.

The appearance of fixed dehydrated non-neoplastic human urothelium viewed by conventional scanning electron microscopy (CSEM) is different from that of frozen hydrated human urothelium viewed by low temperature scanning electron microscopy (LTSEM). In the fixed dehydrated material the surface is formed by well defined, polygonal, domed superficial urothelial cells which have prominent surface microridges. In places intermediate urothelial cells are visible and they have surface microvilli. In the frozen hydrated material viewed by LTSEM most of the surface is smooth. This is formed in part by a glutaraldehyde soluble extracellular secretion which may be a mucin barrier to bacteria. We believe that the rest of the smooth surface is formed by superficial urothelial cells which are not well defined and which lack microridges. There are islands of rounded cells lacking microvilli which are probably intermediate urothelial cells as they correspond in appearance with the intermediate urothelial cells seen in freeze fractured material. It seems likely that fixation and dehydration will cause some change in surface configuration and in theory the frozen hydrated material should more closely resemble the natural state. We believe that LTSEM will be of value in investigating normal and diseased urothelium.

Spontaneous resolution of multiple bladder neoplasms.

A unique case is reported in which multiple well and moderately well differentiated stage I papillary transitional cell carcinomas of the bladder underwent total spontaneous regression. Various histological features of the case suggest an immunological basis for the regression.