Importance of contraction history on muscle force of porcine urinary bladder smooth muscle

Menzel, Robin; Böl, Markus; Siebert, Tobias

doi:10.1007/s11255-016-1482-x

Cited by 10 publications

(28 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The stomachs were taken from 41 freshly killed female pigs (~6 months and 100 kg) of a local slaughterhouse. The experimental set-up, handling, and preparation of gastric smooth muscle tissue have been described earlier (Menzel et al, 2017 ).…”

Section: Methodsmentioning

confidence: 99%

“…The tissue strips were electrically stimulated (Aurora Scientific 701C) with alternating pulses of 1 A, 100 Hz frequency, and 5 ms pulse width (van Mastrigt and Glerum, 1985 ; Menzel et al, 2017 ). All mechanical experiments were conducted at a constant temperature of 32 ± 0.1°C in aerated Krebs solution.…”

Section: Methodsmentioning

confidence: 99%

“…To determine the specific biomechanical muscle properties FLR, FVR, and history-dependent effects, isometric, isotonic, and isokinetic contractions have been performed in accordance with previous studies for smooth muscle tissue (Menzel et al, 2017 ; Seydewitz et al, 2017 ) and skeletal muscles (Böl et al, 2013 ; Siebert et al, 2015 ). Fifty-four ( n = 54) tissue strips were used in total for the in-vitro dynamic parameter determination (Table 1 ).…”

Section: Methodsmentioning

confidence: 99%

“…In order to investigate the impact of ramp length and velocity on history-dependent effects, isokinetic contractions (Herzog and Leonard, 1997 ; Menzel et al, 2017 ) have been applied to n = 17 tissue strips in dependence of varying ramp amplitudes at a given velocity (40% ν max ) and in dependence of different velocities at a constant length amplitude (7% L 0 ), respectively. The isokinetic ramps started after a period of pre-stimulation (around 14 s) under full activation until steady-state maximum isometric force, characterized by the development of a plateau, was reached.…”

Section: Methodsmentioning

confidence: 99%

“…Force generation during gastric distension as well as during and after gastric emptying is accompanied by large muscle length changes and, consequently, might be associated with FE and FD, respectively. Although there are a couple of studies reporting FD and FE for urinary bladder smooth muscle (Minekus and van Mastrigt, 2001 ; van Asselt et al, 2007 ; Menzel et al, 2017 ), to the best of our knowledge, there are no studies of history-effects in the porcine stomach.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Porcine Stomach Smooth Muscle Force Depends on History-Effects

et al. 2017

Self Cite

View full text Add to dashboard Cite

The stomach serves as food reservoir, mixing organ and absorption area for certain substances, while continually varying its position and size. Large dimensional changes during ingestion and gastric emptying of the stomach are associated with large changes in smooth muscle length. These length changes might induce history-effects, namely force depression (FD) following active muscle shortening and force enhancement (FE) following active muscle stretch. Both effects have impact on the force generating capacity of the stomach, and thus functional relevance. However, less is known about history-effects and active smooth muscle properties of stomach smooth muscle. Thus, the aim of this study was to investigate biomechanical muscle properties as force-length and force-velocity relations (FVR) of porcine stomach smooth muscle strips, extended by the analysis of history-effects on smooth muscle force. Therefore, in total n = 54 tissue strips were dissected in longitudinal direction from the ventral fundus of porcine stomachs. Different isometric, isotonic, and isokinetic contraction protocols were performed during electrical muscle stimulation. Cross-sectional areas (CSA) of smooth muscles were determined from cryo-histological sections stained with Picrosirius Red. Results revealed that maximum smooth muscle tension was 10.4 ± 2.6 N/cm2. Maximum shortening velocity (Vmax) and curvature factor (curv) of the FVR were 0.04 ± 0.01 [optimum muscle length/s] and 0.36 ± 0.15, respectively. The findings of the present study demonstrated significant (P < 0.05) FD [up to 32% maximum muscle force (Fim)] and FE (up to 16% Fim) of gastric muscle tissue, respectively. The FE- and FD-values increased with increasing ramp amplitude. This outstanding muscle behavior is not accounted for in existing models so far and strongly supports the idea of a holistic reflection of distinct stomach structure and function. For the first time this study provides a comprehensive set of stomach smooth muscle parameters including classic biomechanical muscle properties and history-dependent effects, offering the possibility for the development and validation of computational stomach models. Furthermore, this data set facilitates novel insights in gastric motility and contraction behavior based on the re-evaluation of existing contractile mechanisms. That will likely help to understand physiological functions or dysfunctions in terms of gastric accommodation and emptying.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Porcine Stomach Smooth Muscle Force Depends on History-Effects

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

Influence of layer separation on the determination of stomach smooth muscle properties

Borsdorf

Böl

Siebert

2021

Pflugers Arch - Eur J Physiol

Self Cite

View full text Add to dashboard Cite

Uniaxial tensile experiments are a standard method to determine the contractile properties of smooth muscles. Smooth muscle strips from organs of the urogenital and gastrointestinal tract contain multiple muscle layers with different muscle fiber orientations, which are frequently not separated for the experiments. During strip activation, these muscle fibers contract in deviant orientations from the force-measuring axis, affecting the biomechanical characteristics of the tissue strips. This study aimed to investigate the influence of muscle layer separation on the determination of smooth muscle properties. Smooth muscle strips, consisting of longitudinal and circumferential muscle layers (whole-muscle strips [WMS]), and smooth muscle strips, consisting of only the circumferential muscle layer (separated layer strips [SLS]), have been prepared from the fundus of the porcine stomach. Strips were mounted with muscle fibers of the circumferential layer inline with the force-measuring axis of the uniaxial testing setup. The force–length (FLR) and force–velocity relationships (FVR) were determined through a series of isometric and isotonic contractions, respectively. Muscle layer separation revealed no changes in the FLR. However, the SLS exhibited a higher maximal shortening velocity and a lower curvature factor than WMS. During WMS activation, the transversally oriented muscle fibers of the longitudinal layer shortened, resulting in a narrowing of this layer. Expecting volume constancy of muscle tissue, this narrowing leads to a lengthening of the longitudinal layer, which counteracted the shortening of the circumferential layer during isotonic contractions. Consequently, the shortening velocities of the WMS were decreased significantly. This effect was stronger at high shortening velocities.

show abstract