| 21. |
- Frederiksen, Hans, et al.
(författare)
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Nerve induced responses and force-velocity relations of regenerated detrusor muscle after subtotal cystectomy in the rat.
- 2004
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Ingår i: Neurourology and Urodynamics. - : Wiley. - 0733-2467 .- 1520-6777. ; 23:2, s. 159-165
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To study the pharmacological and mechanical properties of newly developed detrusor muscle after subtotal cystectomy, to explore if the regenerated detrusor has characteristics similar to the normal bladder base, from which it regenerated, or to the normal bladder body which it replaces. METHODS: Partial cystectomy was performed in female rats. Fifteen weeks later, detrusor strips were cut from supratrigonal and equatorial segments. Unoperated rats served as controls. Responses to field stimulation were obtained in the absence and presence of scopolamine, prazosin, and P2X1 blockade. Dose-response curves were obtained for carbachol, alpha,beta-methylene-ATP, and phenylephrine. Force-velocity data were obtained on maximally activated chemically skinned preparations. RESULTS: Maximal contractile response to field stimulation was 60% of that to high-K+ with no difference between strips from control and cystectomy bladders. Prazosin had no effect. Scopolamine decreased maximal response of supratrigonal strips to 62 +/- 6 (controls) and 61 +/- 4% (operated) of that without blocker. For equatorial strips the decrease was to 81 +/- 5 (controls) and 58 +/- 8% (operated). Frequency-response relations were obtained during blockade with scopolamine, alpha,beta-methylene-ATP, and prazosin. Supratrigonal strips showed a pronounced additional inhibition up to 40 Hz. Equatorial strips from controls were completely inhibited at all frequencies. Equatorial strips from operated bladders were inhibited up to 20 Hz but not at 40 and 60 Hz. Carbachol EC(50) values were similar in all groups. Maximum response to phenylephrine was 10-20% of high-K+ response. Maximal shortening velocity (Vmax) was similar in control supratrigonal and equatorial strips, but was significantly lower in the operated bladders. CONCLUSIONS: (1): A regional difference exists in pharmacological properties of control detrusor, with a considerable contractile response to stimulation remaining in the supratrigonal muscle after simultaneous cholinergic, adrenergic, and purinergic blockade. (2): The new detrusor was functionally well innervated with no supersensitivity to muscarinic stimulation. (3): The newly formed bladder body had pharmacological properties specific for the supratrigonal segment from which it had developed. (4): There was no regional difference in force-velocity characteristics of the control detrusor. (5): The lowered Vmax in the newly formed bladder might thus be related to growth and regeneration of muscle cells.
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| 22. |
- Frederiksen, Hans, et al.
(författare)
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Regeneration of detrusor muscle after subtotal cystectomy in the rat; effects on contractile proteins and bladder mechanics.
- 2001
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Ingår i: Neurourology and Urodynamics. - : Wiley. - 0733-2467 .- 1520-6777. ; 20:6, s. 685-697
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to determine to what extent adult rats can produce new contracting bladder muscle and to see if such newly formed bladder tissue possesses characteristic mechanical properties or whether the ability to recover mechanically is so pronounced that the prehistory of the bladder is unimportant. Subtotal cystectomy was performed in adult female rats, leading to a pronounced decrease in total bladder weight. At 10 weeks, bladder weight had normalized. The histological appearance of such bladders was similar to that of the controls. Active and passive length-tension relations for the detrusor muscle were determined in controls and up to 10 weeks after surgery. Immediately after surgery active and passive forces showed a leftward shift and maximum active force decreased markedly. With time the length-tension curves shifted back to normal, but a decreased active force still remained at 10 weeks. Detrusor actin concentration and detrusor myosin/actin ratio were unaffected by the subtotal cystectomy. Intermediate filament protein/actin ratio showed a significant but transitory increase. We conclude that there is a remarkable recovery of detrusor muscle function after subtotal cystectomy, leading to a normalization of optimum length for active force and a net synthesis of contractile and cytoskeletal proteins. The ability to produce active force does, however, not fully recover.
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| 23. |
- Frederiksen, Hans, et al.
(författare)
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Sprouting of bladder nerves into cystoplastic cecal segment in the rat.
- 1999
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Ingår i: Urological Research. - : Springer Science and Business Media LLC. - 0300-5623 .- 1434-0879. ; 27:6, s. 476-482
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Tidskriftsartikel (refereegranskat)abstract
- Incorporation of bowel into the bladder (enterocystoplasty) has been widely used to increase bladder capacity. It has been reported by others that the response of smooth muscle from the cystoplastic segment of the intestine shifts from that of the intestine (relaxation to α-agonists and ATP) to that of the bladder (contraction to α-agonists and ATP). This suggests a functional integration of the intestinal muscle into the bladder; the mechanisms are unknown. The aims of the present study were (1) to elucidate if there are signs of bladder nerves sprouting across the anastomosis into the intestinal segment, and (2) to study what happens with the intrinsic innervation of the intestinal segment. As a model, we used cecocystoplasty in rats. The bladder was opened and a patch of cecum with intact vascular supply was anastomosed to the bladder. After two to 11 months the rats were sacrificed and the bladders mounted as wholemounts and stained for acetylcholinesterase-containing nerves, or embedded in paraffin for histology. A pronounced degeneration of the myenteric plexus was found in the cecal segments. In some areas, this had proceeded to the extent that the ganglia were isolated ovoid lumps of cells with no apparent connection to other ganglia. Areas lacking ganglia and nerve trunks but still with muscle could be found in all specimens. Abundant axon bundles were demonstrated sprouting from the cut bladder nerves close to the anastomosis. The bundles spread out in a fan-like pattern or were organized as fewer thicker nerves. There were many nerve bundles entering the cecal segment where they branched and the diameter decreased till they no longer became visible. Some nerves reached surviving lumps of myenteric ganglion cells. The results show that the bladder nerves sprout into the anastomosed cecal segment. It is reasonable to assume that these nerves are responsible for the changes in receptor pharmacological properties of the cecal smooth muscle towards that of bladder muscle.
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| 24. |
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| 25. |
- Hjortswang, Henrik, et al.
(författare)
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Contractile properties of ureters from rats with infravesical urinary outlet obstruction
- 1998
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Ingår i: Urological Research. - : Springer Science and Business Media LLC. - 0300-5623 .- 1434-0879. ; 26:5, s. 337-342
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Tidskriftsartikel (refereegranskat)abstract
- Mechanical properties of ureters from rats with infravesical urinary outflow obstruction were studied in vitro. Urinary outflow obstruction was created by partial ligation of the urethra in female rats. After 10 days a marked hypertrophy of the urinary bladder and a dilatation of the ureters were observed. Proximal and distal segments of the ureters from these animals were isolated and mounted in a wire myograph for force registration. Comparisons were made with ureters from control rats. The ureters from the rats with urinary outflow obstruction exhibited a large increase in lumen diameter and an unchanged thickness of the muscle layer. These data suggest that the dilatation of the ureters is associated with growth of the smooth muscle in the wall. All ureter preparations were relaxed in normal physiological salt solution. When the extracellular K+ concentration was increased to 20 mM the dilated ureters became spontaneously active. At [K+] in the range 20-40 mM in the presence of noradrenaline (10(-5) M) all ureters exhibited high-frequency spontaneous contractions. The dilated ureters had a lower frequency of spontaneous contractions and a higher force. The results show a pronounced remodelling of the ureter wall following infravesical outlet obstruction. The structural changes were associated with alterations in the contraction pattern of the preparations, most probably reflecting changes in the excitation-contraction coupling of the growing cells.
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| 26. |
- Håkansson, Ulf, et al.
(författare)
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Organ-sparing reconstructive surgery in penile cancer : initial experiences at two Swedish referral centres
- 2015
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Ingår i: Scandinavian journal of urology. - : Informa Healthcare. - 2168-1805 .- 2168-1813. ; 49:2, s. 149-154
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to present early outcome data for patients treated for penile cancer with organ-sparing reconstructive surgery at two referral centres in Sweden.Material and methods: Oncological, cosmetic and functional outcome and complications were analysed retrospectively during the period 2011-2013. Twelve patients with non-invasive penile cancer were treated with glans resurfacing (GR), while 15 patients with invasive penile cancer underwent total glansectomy with neoglans reconstruction (TGN).Results: The 12 patients treated with GR had a median age of 66 years (range 35-83 years) and a median follow-up time of 16 months (range 4-40 months). All patients showed carcinoma in situ and negative surgical margins in the final pathology report. The 15 patients treated with TGN had a median age of 71 years (range 37-78 years) and the median follow-up time was 10 months (range 1-25 months). All patients had invasive penile cancer and the surgical margins were negative in all cases except one. Complications occurred in five of the 27 patients (18%), and in most cases these were minor and infection related. No recurrences were seen in either group during follow-up, and all patients except one, who had undergone GR, were satisfied with the functional and cosmetic results.Conclusions: GR and TGN seem to be oncologically safe procedures for treating carefully selected patients with penile cancer, and the functional and cosmetic results are promising. Based on these findings, the authors recommend that penile amputation should only be carried out in patients who are not suitable for organ-sparing reconstructive surgery.
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| 27. |
- Johansson, B, et al.
(författare)
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Effects of Tris on vascular smooth muscle
- 1979
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Ingår i: American Journal of Physiology - Heart and Circulatory Physiology. - 1522-1539. ; 237:3, s. 409-411
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Tidskriftsartikel (refereegranskat)
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| 28. |
- Johansson, B, et al.
(författare)
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Responses of smooth muscle to quick load change studied at high time resolution
- 1978
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Ingår i: Blood Vessels. - 0303-6847. ; 15:1-3, s. 65-82
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Tidskriftsartikel (refereegranskat)abstract
- Quick-release and quick-stretch experiments have been performed on preparations of smooth muscle from rat portal vein and rabbit urinary bladder. The low equivalent mass of the isotonic lever (8 mg) implied that inertial oscillations were limited to the first 5-10 msec after the load step. The high time resolution achieved in this way enabled us to separate three components in the length response to a step change in force: (1) an immediate passive elastic recoil, (2) an isotonic velocity transient lasting 50-75 msec and (3) shortening of the contractile element after its full adjustment to the new load. The maximal series elastic recoil was about 10% of the total muscle length in portal vein but only some 3% in urinary bladder. Stiffness of series elasticity increased in proportion to force and was about 3 times higher in bladder than in portal vein at any force level. Force-velocity relations for loads less than Po could be fitted to Hill's equation; Vmax in 4 AC-stimulated portal veins was 0.53 +/- 0.03 muscle lengths/sec and in 8 K+-activated bladder preparations 0.18 +/- 0.01 muscle lengths/sec. Application of loads greater than Po produced rates of lengthening greater than expected from an extrapolation of Hill's hyperbola. The nature of the transient component is discussed in the light of recent studies of force and velocity transients in skeletal muscle.
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| 29. |
- Karbalaei, Mardjaneh, et al.
(författare)
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Impaired contractility and detrusor hypertrophy in cavin-1-deficient mice.
- 2012
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Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 689:1-3, s. 179-185
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Tidskriftsartikel (refereegranskat)abstract
- Caveolae are membrane invaginations present in a variety of cell types. Formation of caveolae depends on caveolins and on the more recently discovered family of proteins known as the cavins. Genetic ablation of caveolin-1 was previously shown to give rise to a number of urogenital alterations, but the effects of cavin-1 deletion on urogenital function remain unknown. Here we characterized detrusor contractility and structure in cavin-1-deficient mice. Electron microscopy demonstrated essentially complete lack of caveolae in the knock-out detrusor, and immunoblotting disclosed reduced levels of cavin-3 and of all caveolin proteins. Bladder weight was increased in male knock-out mice, and length-tension relationships demonstrated a reduction in depolarisation-induced contraction. Contractility in response to muscarinic receptor activation was similarly reduced. Despite these functional changes, micturition patterns were similar in conscious and freely moving animals and diuresis was unchanged. Our breeding additionally disclosed that the number of knock-out mice generated in heterozygous crosses was lower than expected, suggesting embryonic/perinatal lethality. In conclusion, this is the first study to show that cavin-1 is critical for detrusor caveolae and for the overall contractility and structure of the urinary bladder.
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| 30. |
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