Biomaterial Database

Transmural electrical stimulation-induced relaxation of the guinea-pig gall bladder. 1981

M Yoshida, and S Ishiura

The responses of isolated gal bladder to transmural electrical stimulation with rectangular pulses (50 volt, 0.5 ms) of 30 Hz for 10 s at intervals of 30 min were observed for 5 to 6 hours continuously and compared for different values of resting tonus in Krebs solution at 27 degrees C and 37 degrees C Krebs solution, the resting tonus increased gradually with time and became stable at 0.56 +/- 0.07 g (mean +/- S.D.) after 5 h. In 37 degrees C Krebs solution, the resting tonus increased gradually with time and became stable at 1.48 +/- 0.49 g (mean +/- S.D.) to 1.5 +/- 0.19 g (mean +/- S.D.) after 5 h. Monophasic contraction was observed when the resting tonus was lower than 1.49 +/- 0.15 g (mean +/- S.D.), but above this value, biphasic response consisting of contraction and relaxation was observed. Both monophasic and biphasic responses were blocked by atropine and tetrodotoxin. Physostigmine enhanced monophasic contraction, increased the duration of contraction, and abolished the relaxation of biphasic contractile response. The results suggest that contractile response of isolated guinea-pig gall bladder to transmural electrical stimulation was directly induced by acetylcholine released from postganglionic cholinergic fibers. Transmural electrical stimulation with rectangular pulses (50 volt, 0.5 ms) at 10, 20, 30 or 40 Hz for 10 s induced biphasic response in which the contraction varied with frequency, peaking at about 30 Hz, while the relaxation was almost constant. Biphasic relaxation was reduced or inhibited by 2,4-dinitrophenol, ouabain, or K+ -free solution. This suggests that the relaxation phase of the biphasic response induced by transmural electrical stimulation was an active process.

UI	MeSH Term	Description	Entries
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
D009129	Muscle Tonus	The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. (Stedman, 25th ed)	Muscle Tension,Muscle Tightness,Muscular Tension,Tension, Muscle,Tension, Muscular,Tightness, Muscle,Tonus, 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
D010830	Physostigmine	A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity.	Eserine
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005704	Gallbladder	A storage reservoir for BILE secretion. Gallbladder allows the delivery of bile acids at a high concentration and in a controlled manner, via the CYSTIC DUCT to the DUODENUM, for degradation of dietary lipid.	Gallbladders
D006145	Guanethidine	An antihypertensive agent that acts by inhibiting selectively transmission in post-ganglionic adrenergic nerves. It is believed to act mainly by preventing the release of norepinephrine at nerve endings and causes depletion of norepinephrine in peripheral sympathetic nerve terminals as well as in tissues.	((2-Hexahydro-1(2H)-azocinyl)ethyl)guanidine,Guanethidine Monosulfate,Guanethidine Sulfate,Guanethidine Sulfate (1:1),Guanethidine Sulfate (1:2),Guanethidine Sulfate (2:1),Guanethidine Sulfate (2:1), 14C-Labeled,Ismelin,Isobarin,Octadine,Oktadin,Monosulfate, Guanethidine,Sulfate, Guanethidine
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia