scholarly journals Thermodynamic Aspects of Flagellar Activity

1967 ◽  
Vol 47 (2) ◽  
pp. 249-265
Author(s):  
M. E. J. HOLWILL ◽  
N. R. SILVESTER
Keyword(s):  
Regression Line ◽  
Smooth Muscles ◽  
Activation Entropy ◽  
Striated Muscles ◽  
Kcal Mole ◽  
Thermal Dependence ◽  
Activation Free Energy ◽  
The Common ◽  
Cilia And Flagella ◽  
Rate Limiting

1. The frequencies of the beat of cilia and flagella from various organisms have been determined at temperatures in the range 5-35°C. 2. Values of the activation enthalpy (ΔH‡, kcal./mole) and activation entropy (ΔS‡, e.u.) derived from the thermal dependence of frequency show a linear correlation of the form, ΔS‡ = 3·25 ΔH‡-50·75. 3. The corresponding isokinetic activation free energy is 15·6 kcal./mole. 4. The results support a hypothesis that the breakdown of an ATP-ATPase complex could be the common rate-limiting reaction for flagellar activity. 5. Values of ΔH‡ and ΔS‡ for the decay of length or tension in striated muscles also fall on the same regression line but some smooth muscles show deviations.

The Thermal Dependence of Flagellar Activity in Strigomonas Oncopelti

1965 ◽  
Vol 42 (3) ◽  
pp. 537-544
Author(s):  
M. E. J. HOLWILL ◽  
N. R. SILVESTER
Keyword(s):  
Activation Enthalpy ◽  
Beat Frequency ◽  
Published Data ◽  
Activation Entropy ◽  
Present Value ◽  
Kcal Mole ◽  
Thermal Dependence ◽  
Flagellar Beat ◽  
Rate Limiting

The flagellar beat frequency of Strigomonas oncopelti was found by cinémicrophotography at temperatures in the range 4-45° C. The thermal dependence is described by an activation enthalpy (ΔH‡) of 15.4 kcal./mole and an activation entropy (ΔS‡ of -1 e.u. ΔH‡ is comparable with published data on cilia and glycerol-extracted sperm. Values of ΔS‡ (-20 e.u.) deduced from the literature suggest a rate-limiting reaction between ions of like charge although the present value does not support this idea.

Relationship between potency of L-isoprenaline and β-adrenoceptor density estimated in single cells from tracheal smooth muscles of guinea pigs of different ages

1992 ◽  
Vol 70 (4) ◽  
pp. 458-461 ◽  
Author(s):  
Issei Takayanagi ◽  
Mitsutoshi Satoh ◽  
Noriko Kokubu ◽  
Teruko Kato
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Dissociation Constants ◽  
Specific Binding ◽  
Single Cells ◽  
Regression Line ◽  
Smooth Muscles ◽  
Receptor Density ◽  
Age Related ◽  
Β Receptor

An age-related change in potency of L-isoprenaline in the presence of ascorbic acid, desmethylimipramine, corticosterone, pargyline, and phentolamine was obtained in tracheal strips from guinea pigs of differing ages between 6 and 40 weeks. The potency in the strips from 100-week-old guinea pigs did not significantly differ from that in strips from 40-week-old animals. Single cells were prepared from the tracheal muscles of 6-, 10-, 40-, and 100-week-old guinea pigs. The specific binding of [3H]dihydroalprenolol to the single cells was saturable. The dissociation constants of [3H]dihydroalprenolol were in good agreement with those of the membrane fractions from the guinea-pig tracheal muscles, and did not change with age. An excellent relationship between the potency of L-isoprenaline and the maximum binding of [3H]dihydroalprenolol estimated in the preparations from 6- to 40-week-old guinea pigs was found, suggesting that the increase in the potency of L-isoprenaline is due to the increase in the maximum binding or receptor density. The value in the preparations from 100-week-old guinea pigs deviated significantly from the regression line. This suggests the possibility that the decrease in potency in the strips from 100-week-old animals is due to a change in post β-receptor processes in responsiveness.Key words: guinea-pig trachea, single cells, β-receptor density, ageing, dissociation constant.

scholarly journals Embryonic chicken skeletal, cardiac, and smooth muscles express a common embryo-specific myosin light chain.

1985 ◽  
Vol 100 (6) ◽  
pp. 2025-2030 ◽  
Author(s):  
H Takano-Ohmuro ◽  
T Obinata ◽  
M Kawashima ◽  
T Masaki ◽  
T Tanaka
Keyword(s):  
Light Chain ◽  
Gel Electrophoresis ◽  
Myosin Light Chain ◽  
Smooth Muscles ◽  
Light Chains ◽  
Myosin Light Chains ◽  
Striated Muscles ◽  
Two Dimensional Gel Electrophoresis ◽  
Embryonic Chicken ◽  
Muscle Myosin

It has been demonstrated that embryonic chicken gizzard smooth muscle contains a unique embryonic myosin light chain of 23,000 mol wt, called L23 (Katoh, N., and S. Kubo, 1978, Biochem. Biophys. Acta, 535:401-411; Takano-Ohmuro, H., T. Obinata, T. Mikawa, and T. Masaki, 1983, J. Biochem. (Tokyo), 93:903-908). When we examined myosins in developing chicken ventricular and pectoralis muscles by two-dimensional gel electrophoresis, the myosin light chain (Le) that completely comigrates with L23 was detected in both striated muscles at early developmental stages. Two monoclonal antibodies, MT-53f and MT-185d, were applied to characterize the embryonic light chain Le of striated muscles. Both monoclonal antibodies were raised to fast skeletal muscle myosin light chains; the former antibody is specific to fast muscle myosin light chains 1 and 3, whereas the latter recognizes not only fast muscle myosin light chains but also the embryonic smooth muscle light chain L23. The immunoblots combined with both one- and two-dimensional gel electrophoresis showed that Le reacts with MT-185d but not with MT-53f. These results strongly indicate that Le is identical to L23 and that embryonic chicken skeletal, cardiac, and smooth muscles express a common embryo-specific myosin light chain.

Sarcoplasmic Reticulum Function in Smooth Muscle

2010 ◽  
Vol 90 (1) ◽  
pp. 113-178 ◽  
Author(s):  
Susan Wray ◽  
Theodor Burdyga
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Physiological Activity ◽  
Smooth Muscles ◽  
Outward Current ◽  
Integrated Approach ◽  
Transient Outward Current ◽  
Coupling Mechanism ◽  
Striated Muscles ◽  
Development And Aging

The sarcoplasmic reticulum (SR) of smooth muscles presents many intriguing facets and questions concerning its roles, especially as these change with development, disease, and modulation of physiological activity. The SR's function was originally perceived to be synthetic and then that of a Ca store for the contractile proteins, acting as a Ca amplification mechanism as it does in striated muscles. Gradually, as investigators have struggled to find a convincing role for Ca-induced Ca release in many smooth muscles, a role in controlling excitability has emerged. This is the Ca spark/spontaneous transient outward current coupling mechanism which reduces excitability and limits contraction. Release of SR Ca occurs in response to inositol 1,4,5-trisphosphate, Ca, and nicotinic acid adenine dinucleotide phosphate, and depletion of SR Ca can initiate Ca entry, the mechanism of which is being investigated but seems to involve Stim and Orai as found in nonexcitable cells. The contribution of the elemental Ca signals from the SR, sparks and puffs, to global Ca signals, i.e., Ca waves and oscillations, is becoming clearer but is far from established. The dynamics of SR Ca release and uptake mechanisms are reviewed along with the control of luminal Ca. We review the growing list of the SR's functions that still includes Ca storage, contraction, and relaxation but has been expanded to encompass Ca homeostasis, generating local and global Ca signals, and contributing to cellular microdomains and signaling in other organelles, including mitochondria, lysosomes, and the nucleus. For an integrated approach, a review of aspects of the SR in health and disease and during development and aging are also included. While the sheer versatility of smooth muscle makes it foolish to have a “one model fits all” approach to this subject, we have tried to synthesize conclusions wherever possible.

The Croonian Lecture, 1979: Regulation of muscle contraction

1980 ◽  
Vol 207 (1168) ◽  
pp. 259-286 ◽  
Keyword(s):  
Muscle Contraction ◽  
Regulatory Mechanism ◽  
Smooth Muscles ◽  
Regulatory System ◽  
Point Of View ◽  
Striated Muscles ◽  
History Of ◽  
Regulation Of Muscle Contraction ◽  
Almost All ◽  
Evolutionary Point

In this lecture I review briefly the history of the recognition of calcium ion as the sole regulatory factor of muscle contraction at the molecular level and how this led to the discovery of the troponin-tropomyosin system, which is the regulatory system of striated muscles of almost all deuterostomias and some protostomias. This is followed by a brief comment on the myosin-linked regulation, which plays a dominating role in many protostomian muscles. The regulatory mechanism in vertebrate smooth muscle is then discussed; the view is advanced that the leiotonin-tropomyosin system may be the only regulatory device for this muscle. Ca-binding components of troponin and smooth muscles of vertebrates are compared with modulator protein, an omnipresent Ca-binding protein of very conservative nature throughout evolution. Finally, the modes of action of Ca ion in different kinds of cell motility are discussed from an evolutionary point of view.

Parvalbumin content in striated muscles of the common shrew (Sorex araneus)

1998 ◽  
Vol 76 (12) ◽  
pp. 2194-2199 ◽  
Author(s):  
J Savolainen ◽  
M Vornanen
Keyword(s):  
Relaxation Time ◽  
Skeletal Muscles ◽  
Gastrocnemius Muscle ◽  
Fiber Type ◽  
Common Shrew ◽  
Isometric Contractions ◽  
Striated Muscles ◽  
Type Composition ◽  
The Common ◽  
Isometric Twitch

The parvalbumin content of mammalian muscles correlates positively with isometric relaxation rate and fiber type IIB frequency of the muscles but negatively with animal size. Since shrews are small-bodied animals with a relatively low number of type IIB fibers, it is of some interest to know how the parvalbumin content of shrew muscle correlates with the above factors. Parvalbumin content in heart, diaphragm, and gastrocnemius muscle of the common shrew, mouse, and rat was determined electrophoretically. Parvalbumin was not found in heart muscle of any species. Shrew diaphragm (0.29 ± 0.04 g/kg) had significantly less parvalbumin than mouse (0.63 ± 0.11 g/kg) or rat (0.54 ± 0.09 g/kg) diaphragm. Similarly, the parvalbumin content of shrew gastrocnemius muscle (0.28 ± 0.04 g/kg) was significantly lower than in that of mouse (2.88 ± 0.38 g/kg) or rat (0.96 ± 0.25 g/kg) gastrocnemius muscle. The isometric twitch of the gastrocnemius muscle was somewhat faster than the twitch of the diaphragm in all three species. The isometric contractions of shrew and mouse skeletal muscles were generally very similar in duration, with the exception of the relaxation time of the gastrocnemius muscle, which was shorter in the mouse. Diaphragm and gastrocnemius muscle of the rat were clearly slower than the respective muscles in the mouse or shrew with regard to both the contraction and relaxation phases. The half-relaxation time of isometric contractions correlated relatively weakly with parvalbumin content of the muscles (r = 0.40) but more strongly with their fiber IIB content (r = 0.81). The unexpectedly low parvalbumin content and relatively slow rate of contraction in shrew skeletal muscles are attributed to the exceptional fiber type composition, i.e., a high proportion of type IID fibers.

Mechanics and energetics of myosin molecular motors from nonpregnant human myometrium

2011 ◽  
Vol 111 (4) ◽  
pp. 1096-1105 ◽  
Author(s):  
Edouard R. Lecarpentier ◽  
Victor A. Claes ◽  
Oumar Timbely ◽  
Abdelilah Arsalane ◽  
Jacques A. Wipff ◽  
...  
Keyword(s):  
Rate Constants ◽  
Molecular Motors ◽  
Muscle Tension ◽  
Three Dimensional ◽  
Smooth Muscles ◽  
Load Level ◽  
Mechanical Activity ◽  
Human Myometrium ◽  
Striated Muscles ◽  
Tension Peak

Mechanical properties of spontaneously contracting isolated nonpregnant human myometrium (NPHM) were investigated throughout the whole continuum of load from zero load up to isometry. This made it possible to assess the three-dimensional tension-velocity-length (T-V-L) relationship characterizing the level of contractility and to determine crossbridge (CB) kinetics of myosin molecular motors. Seventy-seven muscle strips were obtained from hysterectomy in 42 nonpregnant patients. Contraction and relaxation parameters were measured during spontaneous mechanical activity. The isotonic tension-peak velocity (T-V) relationship was hyperbolic in 30 cases and nonhyperbolic in 47 cases. When the T-V relationship was hyperbolic, the Huxley formalism could be used to calculate CB kinetics and CB unitary force. At the whole muscle level and for a given isotonic load level, part of the V-L phase plane showed a common pathway, so that a given instantaneous length corresponded to only one possible instantaneous velocity, independent of time and initial length. At the molecular level, rate constants for CB attachment and detachment were dramatically low, ∼100 times lower than those of striated muscles, and ∼5 to 10 times lower than those of other smooth muscles. The CB unitary force was ∼1.4 ± 0.1 pN. NPHM shared similar basic contractile properties with striated muscles, reflected in the three-dimensional T-V-L relationship characterizing the contractile level. Low CB attachment and detachment rate constants made it possible to generate normal CB unitary force and normal muscle tension in NPHM, even though it contracted extremely slowly compared with other muscles.

scholarly journals Perspective View on Sorption Thermodynamics: Basic Dye Uptake on Southern Nigerian Clay

2017 ◽  
Vol 13 (18) ◽  
pp. 355
Author(s):  
Daniel C. Emeniru ◽  
John Neminebor ◽  
Justin Ikirigo ◽  
Franklin Sogbara
Keyword(s):  
Isosteric Heat ◽  
Activation Entropy ◽  
Perspective View ◽  
Adsorption Parameters ◽  
Sorption Thermodynamics ◽  
Equilibrium Data ◽  
Value Range ◽  
High Sorption ◽  
Rate Limiting ◽  
Sorption Potential

Macroscopic phenomenon like adsorption has a mechanistic tie typical of thermodynamics and its principles. This work examined the thermodynamic parameters for methylene blue (MB) uptake onto modified Ekowe clay (EC). The purified clay was calcined for 4hrs. at 750 oC to obtain Natural Ekowe Clay (NEC). The purified clay was activated (1.6M H2SO4 (aq)) and calcined for 4hrs. at 750 oC obtaining Activated Ekowe Clay (AEC). Thermodynamic study applied the equilibrium data in determining the activation and heats of adsorption parameters. The concave Eyring plot suggests more than one rate-limiting steps coexisting in the sorption. For temperatures: 25, 30 and 40 oC, activation energies (3) for NEC and AEC lie between 2 - 29kJ/mol inferring physisorption. Negative activation enthalpies (ΔH * ) values confirm exothermic activations. The less negative ΔH * values, in compliance with the significant k2 values varying inversely with temperature, suggests high sorption rate. The negative activation entropy explained an associative uptake and the less negative values are attributive to a physical uptake. Negative free activation enthalpy, ΔG * indicated that uptake on the modified EC is spontaneous. High negativity of ΔG * values suggest strong physic-sorption bond. The negative ΔH * , ΔS * and ΔG * values characterize the physisorption of MB onto modified EC. Values of the isoexcess heats (qisox) obtained: 2.67kJ/mol. (NEC) and 2.47kJ/mol. (AEC) agreed with the value range of <80kJ/mol. typical to physic-sorption. This work opines that sorption of MB onto modified EC is a spontaneous exothermic multilayer phenomenon that progresses heterogeneously with continuous decrease in sorption potential and fall in isosteric heat.

Mechanisms of airway protection during retching, vomiting, and swallowing

2002 ◽  
Vol 283 (3) ◽  
pp. G529-G536 ◽  
Author(s):  
Ivan M. Lang ◽  
Nicole Dana ◽  
Bidyut K. Medda ◽  
Reza Shaker
Keyword(s):  
Muscle Activation ◽  
Smooth Muscles ◽  
Upper Esophageal Sphincter ◽  
Striated Muscles ◽  
Airway Protection ◽  
Laryngeal Elevation ◽  
Glottal Closure ◽  
Adductor Muscles ◽  
Pharyngeal Muscles ◽  
Subglottal Pressure

We investigated the mechanisms of airway protection and bolus transport during retching and vomiting by recording responses of the pharyngeal, laryngeal, and hyoid muscles and comparing them with responses during swallowing and responses of the gastrointestinal tract. Five dogs were chronically instrumented with electrodes on the striated muscles and strain gauges on smooth muscles. Retching and vomiting were stimulated by apomorphine (5–10 ug/kg iv). During retching, the hyoid and thyroid descending and laryngeal abductor muscles were activated; between retches, the hyoid, thyroid, and pharyngeal elevating, and laryngeal adductor muscles were activated. Vomiting always occurred during the ascending phase of retching and consisted of three sequential phases of hyoid and pharyngeal muscle activation culminating in simultaneous activation of all recorded elevating and descending laryngeal, hyoid, and pharyngeal muscles. Retrograde activation of esophagus and pharyngeal muscles occurred during the later phases, and laryngeal adductor was maximally activated in all phases of the vomit. During swallowing, the laryngeal adductor activation was followed immediately by brief activation of the laryngeal abductor. We concluded that retching functions to mix gastric contents with refluxed intestinal secretions and to impart an orad momentum to the bolus before vomiting. During retches, the airway is protected by glottal closure, and between retches, it is protected by ascent of the larynx and closure of the upper esophageal sphincter. The airway is protected by maximum glottal closure during vomiting. During swallowing, the airway is protected by laryngeal elevation and glottal closure followed by brief opening of the glottis, which may release subglottal pressure expelling material from the laryngeal vestibule.

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