Bladder strips

Nelson I think it affects the bursting. There is another clock here. If we add iberiotoxin to bladder strips, the amplitudes and durations of the phasic contractions increase. We also observe a slowing of the phasic contraction frequency. This suggests that it is some sort of slow Ca2+ dependent process that causes longer periods between contractions. The net effect of iberiotoxin is a large increase in force amplitude and duration rise, the frequency goes down. 

A recent patent [26] describes compounds of the pinacidil 9 series where the cyanoguanidine segment has been replaced by the diamino-cyclobutenedione group. Thus compound 29, is the most potent (IC5o=0.52 fiM) of the compounds tested for their ability to inhibit 15 mM KCl-induced contractions in rat isolated bladder strips. Reports of the cardiovascular profile of this compound are awaited with interest to determine whether it has sufficient selectivity for potential in the treatment of urinary incontinence. 

Fig. (21 a). Log cumulative concentration-response curves for contraction induced by diamines (C2-C10) in mouse bladder strips. Contraction responses are expressed as % of the eontraction induced by acetylcholine (ACh, 55 pM). The values represent means S.E.M. (n = 6). 

Transmitter release in parasympathetic neurons in the mouse bladder shows a similar pattern bladder strip contraction was stimulated by single pulses or trains of 20 pulses at 1-50 Hz. Waterman [181] observed that co-conotoxin GVIA and MVIIC inhibited contractions in a concentration-dependent manner with IC50 values of approximately 30 and 200 nM, at low stimulation frequencies the same toxins had little effect at high stimulation frequencies. 

Van Mastright, R., Coosaet, B.L.R.A. and Van Duyl, N.A. (1981) First results of stepwise straining of the human urinary bladder and human bladder strips, Investigative Urology, 19, 58-61. 

A novel series of 1-aryl-3-(thiophen-2-yl)-1 H-1,2,4-triazol-5(4H)-one derivatives was synthesized and evaluated as detrusor muscle relaxants for the treatment of urinary incontinence. The effects of these compounds on bladder contractile function were determined in vitro by using isolated rat bladder strips from male Sprague-Dawley rats that were pre-contracted with carbachol. The results of the SAR studies in this series led to the identification of several potent smooth muscle relaxants. The design, synthesis, and SAR of the series will be presented. 

Male New Zealand rabbits weighing 2-3 kg are eu-thantized under anesthesia and the abdomen is opened to remove the bladder and the urethra. After excess fat and connective tissue is removed, the bladder and the urethra are dissected into dome, trigone and proximal urethral preparations. All strips are cut transversely being approximately 2-6 mm unstretched. 

Pietra et al. (1990) studied the effects of some antidepressants by the in vitro inhibition of carbachol-induced contractions of rat detrusor strip preparations. The detrusor muscle tissue (bladder dome) was cut in a semicircular direction and further dissected into strip preparations measuring approximately 2 x 20 mm. 

Maggi et al. (1985) used isolated detrusor strips of rat bladder connected to an isometric strain gauge and stimulated by field stimulation. 

Ferguson and Marchant (1995) studied the inhibitory actions of GABA on rabbit urinary bladder muscle strips. 

Bumstock et al. (1978) used recorded isometric tension of mucosal-free strips of the detrusor of the bladder from guinea pigs in vitro after electrical field stimulation. 

Hills et al. (1984) used isolated strips of the bladder from female pigs. Bladder neck strips were cut longitudinally and horizontally from the region of the bladder... 

Klarskov (1987) studied the non-cholinergic, non-adrenergic inhibitory nerve responses of bladder outlet smooth muscle from female Danish Landrace pigs in vitro. Trigone strips were taken in an oblique direction from the internal urethral orifice and medially to one of the ureteric orifices, bladder neck strips transversal from the posterior half of the borderline between bladder and urethra, and urethral strips longitudinal from the proximal posterior part. 

Ferguson DR, Marchant IS (1995) Inhibitory actions of GABA on rabbit urinary bladder muscle strips mediation by potassium channels. Br J Pharmacol 115 81-83 Hills J, Meldrum LA, Klarskov P, Burnstock G (1984) A novel non-adrenergic, non-cholinergic nerve-mediated relaxation of the pig bladder neck an examination of possible neurotransmitter candidates. Eur J Pharmacol 99 287-293... 

BTA stat. test strip. A niulticenter trial compared the BTA stat. test with voided urine cytology studies in 499 patients undergoing surveillance cystoscopy for recurrent bladder cancer. The BTA stat. test identified 40% of patients with positive cystoscopy results, and cytology detected 17%. A positive test may provide a higher degree of suspicion for recurrence. A quantitative test in ELISA format, BTA TRAK, is also availabie. 

In our laboratory, the smooth muscles (porcine carotid arteries, veins, uteri, trachea, stomach, and bladder) are pqabeled by incubation with carrier-free [32P]orthophosphate, 2 mCi per 70 ml physiological salt solution (PSS) (Barany et ah, 1992a), and bubbled with a gas mixture of 95% 02-5% CO2 at 37°C, pH 7.4, for 90-120 min. The muscle strips are then washed 15 times with PSS in 30 min to remove 32p from the extracellular space of the muscles. Subsequently the physiological experiments are performed, and the muscles are frozen in liquid nitrogen in various functional states (Barany et ah, 1992a Barany and Barany, 1993a). 

A rapid calcification process on in vitro lipid-exposed Biomer samples occurred within a 1-week period. Strips exposed to the synthetic plasma for less than 2 weeks underwent a rapid surface calcium complexation following a 7-day exposure to a calcium-containing physiological medium (pH 7), whereas unexposed Biomer samples did not calcify. The development of calcium deposits as seen in in vivo bovine LVAD bladders probably would arise from this initial nucleation process. 

GABA receptor agonists have been proposed as drugs for the treatment of bladder instability without side-effects on the central nervous system. 3-Aminopropylphosphinic acid (46, R, R R, R = H) inhibited the contraction of urinary bladder smooth muscle strips of rabbit by 45% when compared with controls. ... 

The original wiper-type units were basically two felt-covered (or similar material) pressure boards that squeeze the strip as it passes between them and produce the rewinding tension in relation to the amount of squeeze applied to them. It has been proven that two rigid boards are not desirable, as pressure is not consistent across the entire face. Therefore, most users have replaced one of the boards with an inflatable air bladder or inflatable fire hose that produces uniform pressure across the length and will conform to any varying strip shape (see Fig. 15). In addition, the pressure is easily recorded from an air-pressure gauge that will allow duplication of settings for a repeat job in the future. 

The elastic modulus of strips of the human bladder have been reported to be about 1.9 X 10° N/m (Van Mastright and Van Duyl, 1981). This is a value reasonably close to that of X -(GVGVP)25i which has been determined to be 1.6 x 10 dynes/cm or 1.6 X 10° N/m. The elastic modulus for X- -poly(GVGIP) is in the range of 4 to 8 X 10° N/m such that a functional range of elastic matrices are available. 

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