Inhibition of short-circuit current by triaminopyrimidine in isolated toad urinary bladder.

The organic cation 2,4,6-triaminopyrimidine (TAP) produced inhibition of short-circuit current (SCC) when added to either the mucosal or serosal surface of the isolated urinary bladder of the toad. Fifty percent inhibition was produced by 10(-3) M TAP in the mucosal solution at pH 6.8 when the mucosal [Na+] was 113 mM. The actions of TAP resemble those produced by amiloride in several ways: a) inhibition of SCC by mucosal application is rapid; b) the mucosal inhibition is fully reversible; c) high concentrations in the serosal solutions produce irreversible inhibition; and d) the concentration required to produce 50% inhibition from the mucosal side is reduced when mucosal [Na+] is reduced. It is postulated that mucosal application of TAP and amiloride inhibit short-circuit current in high-resistance epithelia via action at a common locus.     

Intracellular potentials of toad urinary bladder

Short-circuited urinary bladders of Bufo marinus were impaled with microelectrodes. Intracellular potentials in the order of -80 mV were recorded. On inhibition of apical Na entry they hyperpolarized by about 15 mV and the fractional resistance of the apical membrane increased to near 1.0. These patterns are similar to those of other tight Na transporting amphibian epithelia. On two occasions, stable recordings from a single cell were obtained before and after oxytocin. Intracellular potential and fractional resistance of the apical membrane remained constant despite doubling of Na transport and cellular conductance. This finding suggests that oxytocin stimulates conductive pathways in both, apical and basolateral cell membranes of the toad urinary bladder.     

Intracellular potentials of toad urinary bladder

Short-circuited urinary bladders of Bufo marinus were impaled with microelectrodes. Intracellular potentials in the order of -80 mV were recorded. On inhibition of apical Na entry they hyperpolarized by about 15 mV and the fractional resistance of the apical membrane increased to near 1.0. These patterns are similar to those of other tight Na transporting amphibian epithelia. On two occasions, stable recordings from a single cell were obtained before and after oxytocin. Intracellular potential and fractional resistance of the apical membrane remained constant despite doubling of Na transport and cellular conductance. This finding suggests that oxytocin stimulates conductive pathways in both, apical and basolateral cell membranes of the toad urinary bladder.     

Release of cyclic AMP by toad urinary bladder.

Cyclic AMP accumulates in the Ringer solution bathing the toad urinary bladder in vitro. At least 4 times more cyclic AMP is released into the solution bathing the serosal surface than into the solution bathing the mucosal surface. Most of the cyclic AMP originates in the epithelial cells rather than the stroma. Vasopressin increased the content of cyclic AMP in the epithelial cells and increases the amount of cyclic AMP in the Ringer solution. Since there is not an increase in medium cyclic AMP when cell cyclic AMP levels are increased by theophylline, it is suggested that theophylline may reduce the permeability of the cell membrane to cyclic AMP. Finally, it is demonstrated that 10 mM NaF increase the amount of cyclic AMP in the epithelial cells and in the solution bathing the bladder, but block the effect of vasopressin on water permeability, presumably at a step subsequent to the formation of cyclic AMP.     

Excess antibody immunoassay for rat glandular kallikrein. Measurement of kallikrein complexed with inhibitors and in plasma

We have recently developed an immunoradiometric assay (IRMA) for specific measurement of immunoreactive kallikrein which allows a simultaneous determination of the enzymatic activity of kallikrein. This paper describes the application of this method for measurements of glandular kallikrein complexed with inhibitors. Interference by low molecular weight inhibitors such as benzamidine and Trasylol was easily overcome by increasing the amount of immobilized anti-kallikrein antibody added in the assay, and by prolonging the incubation time of the antigen-binding step. The recovery of kallikrein in complex with plasma inhibitors was complete only when the anti-kallikrein antibody was immunoadsorbed onto a solid-phase sheep anti-rabbit immunoglobulin. The dose-response curve of glandular kallikrein in plasma paralleled that of purified kallikrein in both the immunoradiometric and the immunoenzymometric assays. The concentration of immunoreactive glandular kallikrein in normal rat plasma was 12.8 +/- 4.3 nU/ml. The enzymatic activity of this immunoreactive kallikrein was 86% inhibited.     

Squamous and glandular lesions of the urinary bladder

A wide range of squamous and glandular lesions can arise within the urinary bladder. Familiarity with benign entities is important as florid examples can mimic a neoplastic process while certain histologically bland lesions have a potential malignant association.When dealing with overtly malignant lesions, careful morphologic assessment and clinicopathologic correlation are essential. This paper provides a broad overview of the spectrum of squamous and glandular lesions encountered in the bladder with an emphasis on important morphologic features, relevant clinical implications and common differential diagnoses in routine diagnostic practice.     

膀胱良性腺样病变的病理学诊断

膀胱可发生各种腺性和假腺样病变,这些病变可从完全良性到生物学行为呈侵袭性的原发或继发恶性肿瘤.膀胱良性腺性病变如囊性膀胱炎和腺性膀胱炎在小的活检标本中可误诊为恶性病变.同样,苗勒起源的异位组织偶可见于膀胱,这些病变应与膀胱真性腺样肿瘤区分开来,否则会引起不适当的治疗.本文就发生于膀胱的各种腺性和腺样病变进行介绍,重点是这些腺样病变的鉴别诊断和临床意义.