Biomaterial Database

Activation of protein kinase C accelerates contraction kinetics of airway smooth muscle. 1996

U Peiper, and S C Knipp, and B Thies, and R Henke

Physiologisches Institut, Universitätskrankenhaus Eppendorf, Hamburg, Germany.

Contraction kinetics of isolated rat tracheal smooth muscle were studied by analysing the increase of force subsequent to force-inhibiting passive length changes lasting 1 s (100 Hz, sinus, 5% of muscle length). Compared with carbachol activation, phorboldibutyrate (PDBu)-induced stimulation of protein kinase C (PKC) demonstrated no significant difference in the extent of force development in the polarized preparation [mean peak force 9.16 +/- 0.37 mN (carbachol) vs. 9.12 +/- 0.37 mN (PDBu)]. However, the time constant calculated for the slow component of post-vibration force recovery was 6.40 +/- 0.29 s after addition of PDBu vs. 22.39 +/- 1.40 s during carbachol activation, indicating a significant phorbol ester-induced acceleration of the cross-bridge cycling rate. In the K-depolarized preparation, treatment with 26.4 microM indolactam (IL) to activate PKC produced muscle relaxation (9.94 +/- 0.16 mN measured 0-30 min after the onset of depolarization vs. 4.13 +/- 0.05 mN measured during 30-60 min of IL treatment). Again, even in the presence of high sarcoplasmic Ca2+ resulting from tonic depolarization, PKC activation was associated with a distinct diminution of the time constant (25.99 +/- 0.79 s during the first 30 min of depolarization vs. 10.32 +/- 0.21 s during 30-60 min of IL treatment). In contrast, addition of 0.035 microM verapamil, 1.5 microM isoproterenol, and 32 microM dibutyryl-cAMP to the bathing medium induced relaxation without affecting the rate of post-vibration force recovery. The results suggest that the calcium-dependent signal cascade (agonist receptor/inositol trisphosphate/ Ca(2+)-calmodulin/myosin light chain kinase) hardly affects the regulation of contraction kinetics in the tonically activated intact smooth muscle preparation. PKC stimulation, however, accelerates actin/myosin interaction kinetics, possibly by inhibition of phosphatase(s).

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007769	Lactams	Cyclic AMIDES formed from aminocarboxylic acids by the elimination of water. Lactims are the enol forms of lactams.	Lactam,Lactim,Lactims
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011493	Protein Kinase C	An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.	Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D011976	Receptors, Muscarinic	One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.	Muscarinic Acetylcholine Receptors,Muscarinic Receptors,Muscarinic Acetylcholine Receptor,Muscarinic Receptor,Acetylcholine Receptor, Muscarinic,Acetylcholine Receptors, Muscarinic,Receptor, Muscarinic,Receptor, Muscarinic Acetylcholine,Receptors, Muscarinic Acetylcholine
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.