Actomyosin, collagen, and cell hypertrophy in intestinal muscle after jejunoileal bypass

Bowers, R. L.; Eeckhout, C.; Weisbrodt, N. W.

doi:10.1152/ajpgi.1986.250.1.g70

Cited by 8 publications

(8 citation statements)

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“…Results of these experiments indicate that there are biochemical differences among the three types of muscle from opossum esophagus. Although the values obtained for total protein content were in the same range as those reported for other gastrointestinal muscles (10,20,21), the fact that the total protein per wet weight of LES was slightly less than that of SM and ST suggests that LES has a greater portion of its mass composed of nonprotein solids or water.…”

Section: Discussionsupporting

confidence: 74%

“…The esophagi used for actomyosin and collagen determinations were dissected in the presence of 0.1 mM phenylmethylsulfonylfluoride (PMSF, Sigma Chemical Co., St. Louis, MO), 1 pglml pepstatin A (Sigma), and 5 pglml leupeptin (Sigma). The muscle strips were cut and prepared for actomyosin and collagen determinations as described previously (10). Briefly, half of each muscle strip (25-50 mg) was placed in the appropriate solution for actomyosin or collagen determination.…”

Section: Biochemical Determinationsmentioning

confidence: 99%

“…The actomyosin content of the tissue extracts was determined after SDS-PAGE of the samples and rabbit skeletal muscle actin (Sigma) and myosin (Sigma) (10). After staining and destaining, the density of the actin and myosin heavy chain bands was determined on a laser scanner (LKB, Piscataway, NJ), and the area under the peak corresponding to actin or myosin was determined by computer-assisted planimetry (9845A; Hewlett Packard, Leveland, CO).…”

Section: Biochemical Determinationsmentioning

confidence: 99%

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Actomyosin, Collagen, and Succinate Dehydrogenase Determinations in Opossum Esophageal Muscles

Bowers

Dubinsky

Weisbrodt

1990

Neurogastroenterology Motil

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The contractile activities of the lower esophageal sphincter (LES), esophageal body smooth muscle (SM), and esophageal body striated muscle (ST) of the opossum differ in their dependence on oxygen. One possible explanation for this difference in oxygen dependence is that the muscles differ in their oxidative capacities. The purpose of this study was to estimate the oxidative. capacity of these muscles by measuring the activity of succinate dehydrogenase (SDH). Since the muscles are structurally as well as functionally distinct, we also determined the amount of actin, myosin, collagen, and total protein in the tissues. LES contained less total protein and more collagen than SM and ST. The actin contents per unit of total protein of all three tissues were similar. The myosin contents and the actin: myosin ratios, however, were significantly different among all three muscles. The interpretation of the values of the SDH activity depended on the manner in which the data were expressed. When SDH activity was expressed relative to the tissue content of myosin, the values were different among all three muscles. These findings support the hypothesis that there is biochemical variability in these three esophageal muscles that may account in, part for their differences in contractile behavior.

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Section: Discussionsupporting

confidence: 74%

Section: Biochemical Determinationsmentioning

confidence: 99%

Section: Biochemical Determinationsmentioning

confidence: 99%

See 1 more Smart Citation

Actomyosin, Collagen, and Succinate Dehydrogenase Determinations in Opossum Esophageal Muscles

Bowers

Dubinsky

Weisbrodt

1990

Neurogastroenterology Motil

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“…Sim ilar to methods used previously, the tissue was homogenized with 35 volumes of extraction buffer (25 mM NaP0 4 , pH 7) with 1% j3ME, 0.1 /-LM PMSF, 1 /-LglmL pepstatin A, and 5 /-LglmL leupeptin (8)(9)(10). SDS was added to a 1% concentration.…”

Section: Resultsmentioning

confidence: 99%

Characterization of Actin and Myosin in the Developing Stomach

1995

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During growth and development, dietary intake changes from being predominantly liquid in the newborn period to mixed solid liquid meals. These alterations in diet vary the functional demands placed on the stomach. It has been shown that, during development, smooth muscle of the stomach undergoes changes in the mechanism responsible for the contractile process. In this study, we have investigated the possibility that there are structural changes in two of the major proteins that are responsible for generation of force during smooth muscle contraction: actin and myosin. Actin and myosin were identified in newborn kittens (1 wk old) and adult gastric smooth muscle using one-dimensional SDS-PAGE. Although both the antrum and fundus of the kitten have significantly smaller total amounts of actin and myosin per mg protein than the adult, the ratio of actin to myosin is not significantly different between the age groups. Two different The changes in diet ary constitu ents during growth and development from predominantl y liquid to mixed solid liquid meals places an increasing burd en on the stomach that is required to triturate these solids and empty them from the stoma ch. The fundus or proxim al portion of the stomach is respon sibl e for the storage and empty ing of gastric food stuffs, whereas the antrum redu ces the size of ing ested solids and faci litates emptying (1). Th ere is a growing bod y of experiment al ev ide nce suggesting that functional characteristics of smoo th muscle in the sto mac h und ergo changes that parallel these alte rations in dietary mili eu. Th e frequ enc y and amplitude of contractions in the ca nine stoma ch increase during the newborn period (2). Th e in vitro force-generating capacit y of smoo th mu scle from the stomach of newborn rabbit s is less than that of adult gastri c muscl e, and this reduction in forcegeneratin g capacity did not appear to be accounted for by changes in receptor function (3,4). In addition to these quantitative differences in ability to ge nerate force, we have recentl y repo rted that isolated muscle ce lls from the antrum of the adult cat use intr acellular Ca 2 + stores that are not available for kitten antral cells (5). We observed an increase in the amount of MHC2 in the adult, which resulted in a decreased ratio of MHC1 to MHC2 in the adult. We postulate that the decreased quantity of actin and myosin in the kitten stomach and the observed changes in the ratio of the MHC isoforms are related to changes in the gastric motor that occur during growth and development. (Pediatr Res 37: 202-206, 1995) Abbreviations PMSF , phenylmethyl sulfanyl fluoride f3ME, f3-mercaptoethanol MHC , myosin heavy chain Actin and myo sin are two of the major structural proteins involved in the contractil e machinery of the cell. Th e generation of tension during muscle contraction is the result of the interaction between myos in heads and adjacent actin filaments (6). Previous studies have suggested that changes in the absolute amount and relative abundance of isoforms ...

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“…There is a hypertrophy of the smooth muscle cells such that the mass of muscle per unit length of intestine increases (4,5,8). This increase in functioning muscle mass of the bypassed segment, seen when normal transit has returned, was felt to be in response to the altered intestinal contents and was postulated to be responsible in part for the return of normal transit.…”

Section: Introductionmentioning

confidence: 99%

Effect of Acetylcysteine on Intestinal Smooth Muscle after Small Bowel Bypass in Rats

Weisbrodt

Green

Belloso

et al. 1990

Neurogastroenterology Motil

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Transit through the bypassed intestine is initially depressed in rats that have 70% of their jejunoileum bypassed. In this study, the influence of intraluminal infusion of the mucolytic N‐acetyl‐L‐cysteine on the depressed transit was determined. Beginning on the first postoperative day, the bypassed intestines were infused continuously with either saline or a 6% solution of acetylcysteine. In one group of animals, transit was determined on the third day after operation. In another group, segments of intestine were evaluated morphometrically on the twelfth day. Transit rates in bypassed intestines of those animals infused with acetylcysteine were higher than those in bypassed intestines of animals infused with saline. Compared to saline infusion, acetylcysteine infusion resulted in the following structural changes in the bypassed intestine: decreases in the total cross‐sectional area of the gut, the wet weight and cross‐sectional area of the intestinal muscle, and the thickness of the circular muscle layer. These findings support the hypothesis that the reduced transit and muscular hypertrophy seen in the uninfused bypassed intestine of rats early after operation may be due to alterations in intestinal contents which include mucus.

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Actomyosin, collagen, and cell hypertrophy in intestinal muscle after jejunoileal bypass

Cited by 8 publications

References 0 publications

Actomyosin, Collagen, and Succinate Dehydrogenase Determinations in Opossum Esophageal Muscles

Actomyosin, Collagen, and Succinate Dehydrogenase Determinations in Opossum Esophageal Muscles

Characterization of Actin and Myosin in the Developing Stomach

Effect of Acetylcysteine on Intestinal Smooth Muscle after Small Bowel Bypass in Rats

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