Proteolytic Inactivation of Substance P and Neurokinin A in the Longitudinal Muscle Layer of Guinea Pig Small Intestine

2006 ◽  
Vol 47 (3) ◽  
pp. 856-864 ◽  
Author(s):  
R. Nau ◽  
G. Schäfer ◽  
C. F. Deacon ◽  
T. Cole ◽  
D. V. Agoston ◽  
...  
Keyword(s):  
Small Intestine ◽  
Substance P ◽  
Guinea Pig ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Neurokinin A ◽  
Longitudinal Muscle Layer

Separation of enkephalin-degrading enzymes from longitudinal muscle layer of bovine small intestine

1985 ◽  
Vol 34 (17) ◽  
pp. 3179-3183 ◽  
Author(s):  
Tadahiko Hazato ◽  
Mariko Shimamura ◽  
Ryoichi Kase ◽  
Mikio Iijima ◽  
Takashi Katayama
Keyword(s):  
Small Intestine ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Longitudinal Muscle Layer ◽  
Degrading Enzymes ◽  
Bovine Small Intestine

Responses of muscles of cat small intestine to autonomic nerve stimulation

1963 ◽  
Vol 204 (2) ◽  
pp. 352-358 ◽  
Author(s):  
Gordon L. Van Harn
Keyword(s):  
Small Intestine ◽  
Muscle Contraction ◽  
Nerve Stimulation ◽  
Sympathetic Nerve ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Slow Waves ◽  
Intraluminal Pressure ◽  
Sympathetic Nerve Stimulation ◽  
Longitudinal Muscle Layer

The externally recorded slow waves from the cat small intestine originate in the longitudinal muscle layer. In vitro the slow waves are recorded from all layers of the intestine if the segment is not immersed in a saline bath. When the longitudinal layer is removed from one region, the magnitude of the slow-wave potential in the other intestinal layers decreases as the distance from the intact longitudinal muscle layer is increased. An active intestine, in vivo, responds to sympathetic nerve stimulation by a hyperpolarization, cessation of spikes, and inhibition of muscle contraction. During inactivity of the intestine, either vagus or sympathetic nerve stimulation results in a depolarization, initiation of spikes, and muscle contraction. The nature of the response is influenced by the frequency of nerve stimulation and by the level of activity of the intestinal muscle, which is altered by intraluminal pressure changes. The effect of drugs on the response of the intestine to vagal and sympathetic nerve stimulation is such as to indicate that both inhibitory and excitatory nerve fibers are present in each of the autonomic nerves. The duration of the latent period of the response is long and highly variable, and a response requires 50–100 nerve volleys.

scholarly journals Relationship between stimulated phosphatidic acid production and inositol lipid hydrolysis in intestinal longitudinal smooth muscle from guinea pig

1987 ◽  
Vol 244 (3) ◽  
pp. 763-768 ◽  
Author(s):  
R S E Mallows ◽  
T B Bolton
Keyword(s):  
Smooth Muscle ◽  
Small Intestine ◽  
Substance P ◽  
Guinea Pig ◽  
Phosphatidic Acid ◽  
Inositol Phosphates ◽  
Muscle Layer ◽  
Phospholipid Hydrolysis ◽  
Longitudinal Smooth Muscle ◽  
Inositol Phospholipid

Accumulation of [32P]phosphatidic acid (PA) and total [3H]inositol phosphates (IPs) was measured in the longitudinal smooth-muscle layer from guinea-pig small intestine. Stimulation with carbachol, histamine and substance P produced increases in accumulation of both [3H]IPs and [32P]PA over the same concentration range. The increase in [32P]PA accumulation in response to carbachol (1 microM-0.1 mM) was inhibited in the presence of atropine (0.5 microM). Buffering the external free [Ca2+] to 10 nM did not prevent the carbachol-stimulated increase in [32P]PA accumulation. Carbachol and Ca2+ appear to act synergistically to increase accumulation of [32P]PA. In contrast, although incubation with noradrenaline also increased accumulation of [3H]IPs, no increase in accumulation of [32P]PA could be detected. These results suggest that an increase in formation of IPs is not necessarily accompanied by an increase in PA formation, and imply the existence of receptor-modulated pathways regulating PA concentrations other than by phospholipase-C-catalysed inositol phospholipid hydrolysis.

Transmission of electrical activity through the gastroduodenal junction

1965 ◽  
Vol 208 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Alex Bortoff ◽  
Noah Weg
Keyword(s):  
Small Intestine ◽  
Electrical Activity ◽  
Longitudinal Muscle ◽  
Muscle Layer ◽  
Slow Waves ◽  
Pyloric Antrum ◽  
Longitudinal Muscle Layer ◽  
Proximal Duodenum ◽  
Electrical And Mechanical Activities ◽  
Electrode Technique

The electrical and mechanical activities of the gastroduodenal junction were studied in isolated cat preparations, using the pressure-electrode technique. The spontaneous electrical activity of the pyloric antrum consists of periodic depolarizations, the configuration of which is somewhat more complex than that of comparable potentials recorded from the longitudinal muscle layer of the small intestine. Like their intestinal counterparts these antral slow waves may be associated with spike potentials which are thought to initiate contractions. The electrical activity at the gastroduodenal junction consists of a combination of antral and duodenal slow waves, sometimes accompanied by spike potentials. In the proximal duodenum, antral slow waves are represented by periodic depolarizations which may be associated with spike potentials followed by contractions. Because of the extension of the antral slow waves into the proximal duodenum, contractions initiated in the antrum may also extend into the proximal duodenum. It is concluded that the gastroduodenal junction is a transition zone, coordinating the electrical and corresponding mechanical activities of the antrum and proximal duodenum.

Electrical activity of longitudinal and circular muscle during peristalsis

1983 ◽  
Vol 244 (1) ◽  
pp. G83-G88 ◽  
Author(s):  
S. Yokoyama ◽  
R. A. North
Keyword(s):  
Small Intestine ◽  
Substance P ◽  
Guinea Pig ◽  
Action Potentials ◽  
Muscle Activation ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Intraluminal Pressure ◽  
Longitudinal Muscles ◽  
Spike Bursts

Action potentials were recorded simultaneously from the longitudinal and circular muscle layers of the guinea pig isolated small intestine. Both the graded reflex of the longitudinal muscle and the peristaltic reflex proper could be evoked by raising the intraluminal pressure. At low intraluminal pressures, intervals between spike bursts of the circular muscle were longer than those of the longitudinal muscle. The higher the intraluminal pressure, the shorter became the intervals between spike bursts in the circular muscle, until both muscle layers showed synchronous discharge of action potentials. Tetrodotoxin (100 nM) abolished the excitation of both circular and longitudinal muscles produced by raising intraluminal pressure. Hexamethonium (280 microM) abolished excitation of the circular muscle but not that of the longitudinal muscle. Atropine (100 nM) reduced the excitatory effects of raising pressure on both muscle layers but did not abolish them. The atropine-resistant excitation of the circular, but not the longitudinal, muscle was reversibly blocked by exposure to substance P (100–500 nM). Chymotrypsin (200 micrograms/ml) reversibly abolished the atropine-resistant excitation of the circular muscle. It was concluded that during peristalsis both longitudinal and circular muscle layers are activated synchronously; muscle activation during peristalsis is not entirely cholinergic but may involve in addition a substance P-like peptide.

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