Inhibition of cycling and noncycling cross bridges in skinned smooth muscle by vanadate

Nayler, Ross A.; Sparrow, Malcolm

doi:10.1152/ajpcell.1986.250.2.c325

Cited by 32 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Greater increases in Pi (12 mm) were associated with only marginal decreases (< 15%) in the isometric force in skinned guinea-pig taenia caeci stimulated at maximal calcium levels (Schneider, Sparrow & Riiegg, 1981), or after thiophosphorylation (Nayler & Sparrow, 1986). IncreasingPi, however, did increase the rate of relaxation following the imposition of calcium-free conditions.…”

Section: Discussionmentioning

confidence: 95%

Effects of hypoxia on high‐energy phosphagen content, energy metabolism and isometric force in guinea‐pig taenia caeci.

Ishida

Rutgeerts

1990

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. Previously, Ishida, Takagi & Urakawa (1984) reported that, in the presence of high K+ (45-4 mM) under hypoxia (95% N2-5 % CO2 bubbling), tension and ATP content of the smooth muscle of the guinea-pig taenia caeci increased concomitantly when the glucose concentration was raised. Tension and energy metabolism of the taenia seemed to be closely correlated. In the present experiments, we investigated the metabolic changes during the relaxation phase after the taenia was exposed to hypoxia in the presence of high K+ by measuring the content of phosphagen, inorganic phosphate (Pi) and lactate in the tissue. Oxygen consumption and lactate release from the tissue were also determined to estimate the rate of ATP synthesis.2. Under hypoxic conditions, high-K+-induced tension decreased to one-tenth of maximum in aerobic conditions (95 % 02-5 % CO2 bubbling); increasing the calcium concentration from 2-5 to 10 mm had no effect. To test receptor-associated stimuli, carbachol or histamine (both 5 #M) had little effect on tension in hypoxia. The calcium ionophore A23187 (10 fM) also did not produce any significant contraction in the presence of high K+ under hypoxia.3. Hypoxia in the presence of high K+ elicited a rapid decrease in phosphocreatine, approximately in parallel with the decrease in tension. The ATP content decreased gradually while Pi content increased. Lactate content increased rapidly and then partially decreased.4. The rate of ATP synthesis estimated from the oxygen consumption and lactate release of the taenia was linearly correlated with tension development under aerobic and hypoxic conditions. 5. These results suggest that the decrease in tension of the taenia observed under hypoxic conditions is due to an inhibition of energy metabolism, and not due to an oxygen-sensing' step in excitation-contraction coupling.

show abstract

Section: Discussionmentioning

confidence: 95%

Effects of hypoxia on high‐energy phosphagen content, energy metabolism and isometric force in guinea‐pig taenia caeci.

Ishida

Rutgeerts

1990

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…They were calculated to contain 10 mM EGTA, 30ram imidazole, 0.3 mM DTT (pH of 6.8) with an ionic strength of 0.085 M using potassium acetate (Naylor & Sparrow, 1986;Arner el al., 1987;Clark et al, 1993). Control Stimulating (pCa 4.5) and Relaxing (pCa 9) Solutions also contained 3.16 mM MgATP and 12 mM PCr.…”

Section: Solutionsmentioning

confidence: 99%

Creatine kinase activity associated with the contractile proteins of the guinea-pig carotid artery

Clark

Khuchua²,

Boehm

et al. 1994

J Muscle Res Cell Motil

View full text Add to dashboard Cite

Activity and role of creatine kinase associated with contractile proteins of vascular smooth muscle have been investigated using skinned guinea-pig carotid artery rings. Membrane solubilization was performed with the detergent Triton X-100. Creatine kinase activity, isoenzyme profile as well as mechanics were performed on the Triton skinned carotid artery rings. Total creatine kinase activity was 47.3 +/- 9.3 IU g-1 ww and electrophoresis showed BB, MB, and MM isoforms (BB-CK being the predominant isoenzyme). One hour incubation with Triton X-100, produced predominantly BB-CK remaining with the myofibrils with some MB, representing 23% of the preskinned creatine kinase activity. When relaxed carotid artery rings were exposed to pCa 9 in the presence of 250 microM ADP, 0 ATP, and 12 mM phosphocreatine, tension was not significantly different from resting tension, but changing to pCa 4.5 caused the carotid artery rings to generate 49.5 +/- 4.5% of maximal tension. When a high-tension rigor state was achieved (250 microM ADP, 0 ATP, 0 phosphocreatine, and pCa 9), the addition of 12 mM phosphocreatine effected significant relaxation. These observations implicate an endogenous form of creatine kinase, associated with the myofilaments, which is capable of producing enough ATP for submaximal tension generation and significant relaxation from rigor conditions. These results suggest co-localization of ATPase, MLCK, and creatine kinase on the contractile proteins of the carotid artery. Such an enzymic association may play a role in the energetic supply to the contractile apparatus of vascular smooth muscle.

show abstract

“…The relationship between force and [Ca2 '] has been studied in skinned smooth-muscle strips (3)(4)(5)(6)(7)(8)(9)(10)(11) and in smooth muscles that were loaded with aequorin by temporarily permeabilizing the tissue (12). The sensitivity of force to [Ca24] found in chemically permeabilized (skinned) preparations by various investigators varies by almost two orders of magnitude, and several studies showed that the sensitivity can be altered by calmodulin addition (5,6,13) or by varying either inorganic phosphate (11) or Mg2+ concentration (10).…”

mentioning

confidence: 99%

Relationship between force and Ca2+ concentration in smooth muscle as revealed by measurements on single cells.

Yagi

Becker

Fay

1988

Proc. Natl. Acad. Sci. U.S.A.

104

View full text Add to dashboard Cite

The role of Ca24 in regulating smooth muscle contraction was investigated by measuring isometric force and [Ca2I] simultaneously in individual single smooth-muscle cells. [Ca24] was measured with fura-2 and a high timeresolution dual-wavelength digital microfluorimeter, and force was measured with an ultrasensitive force transducer attached to a probe around which was tied one end of the cell. Both [Ca2+1 and force increase after maximal electrical stimulus, with [Ca24] Calcium is considered the key regulator of contraction of smooth muscle (1, 2), although details of this regulation remain somewhat unclear. The relationship between force and [Ca2 '] has been studied in skinned smooth-muscle strips (3-11) and in smooth muscles that were loaded with aequorin by temporarily permeabilizing the tissue (12). The sensitivity of force to [Ca24] found in chemically permeabilized (skinned) preparations by various investigators varies by almost two orders of magnitude, and several studies showed that the sensitivity can be altered by calmodulin addition (5,6,13) per se, accounts for the several hundred-msec delay between stimulation and onset of active-force production characteristic of smooth muscle. Finally, our results show that the contractile process exhibits decreasing sensitivity to calcium during slow contraction-relaxation cycles. METHODSSmooth muscle cells were isolated from the stomach of the toad Bufo marinus as described (14). Briefly, the procedure involves incubating thin slices of stomach wall first in a dilute solution of collagenase and trypsin and then in a solution of collagenase alone. Cells released from the tissue in this latter solution are collected by mechanically separating the tissue from the cell suspension. Soybean trypsin inhibitor was added to all cell suspensions to suppress any remaining trypsin activity.Cells were loaded with the calcium-sensitive dye fura-2 (15) by incubating them in a solution of the acetoxymethyl ester form ofthe dye, fura-2/AM (Molecular Probes, Eugene, OR). Cells were incubated in this solution at 31°C for 60 min and then returned to room temperature. The amount of fura-2/AM added to the cell suspension was adjusted according to cell density at the ratio of 1.25 x 10-9 mol of fura-2/AM per 106 cells. These loading conditions were found to produce intracellular fura-2 concentrations of 30-100 ,M as estimated by comparing total fluorescence to that from droplets of fura-2 solutions in oil.A dilute suspension of cells that had been loaded with fura-2 was placed on a cover-slip chamber on the stage of an inverted microscope, and the cells were allowed to settle. A single cell was then attached at both ends to two special glass microprobes, each of which had a single anionic-exchangeresin particle cemented to its tip. After attachment of cell to probe, a small section of the muscle cell was wrapped at each end by micromanipulation around the attached probe. The procedure was basically that described by Warshaw and Fay (16). One probe was attached to a micr...

show abstract

Inhibition of cycling and noncycling cross bridges in skinned smooth muscle by vanadate

Cited by 32 publications

References 15 publications

Effects of hypoxia on high‐energy phosphagen content, energy metabolism and isometric force in guinea‐pig taenia caeci.

Effects of hypoxia on high‐energy phosphagen content, energy metabolism and isometric force in guinea‐pig taenia caeci.

Creatine kinase activity associated with the contractile proteins of the guinea-pig carotid artery

Relationship between force and Ca2+ concentration in smooth muscle as revealed by measurements on single cells.

Contact Info

Product

Resources

About