Elektrophysiologische Untersuchungen zur Spontanaktivität isolierter Muskelpräparate aus verschiedenen Abschnitten des Meerschweinchen-Magens

Golenhofen, K.; D, von Loh; Milenov, K

doi:10.1007/bf00593460

Cited by 25 publications

(11 citation statements)

References 15 publications

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“…Slow waves are inhibited by metabolic inhibitors in the guinea-pig stomach (Nakayama et al, 1997). Slow waves are sensitive to temperature, and the temperature coefficient (Q10) of their frequency is high (Q10 = 2-3) (Job, 1969;Golenhofen et al, 1970;Ohba et al, 1975). These observations again suggest that mitochondrial activity may be causally related to the generation of spontaneous activity.…”

Section: Introductionmentioning

confidence: 91%

Metabolic component of the temperature-sensitivity of slow waves recorded from gastric muscle of the guinea-pig

Nakamura

Kito

Hashitani

et al. 2006

J. Smooth Muscle Res.

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The effects of changes in temperature on slow waves were investigated in smooth muscle tissues isolated from the guinea-pig gastric antrum. Within the range 24°C to 42°C, elevation of temperature increased the frequency and maximum rate of rise of the upstroke phase (dV/dt) of slow waves and decreased their duration, with no alteration to amplitude or resting membrane potential. These observations also applied to follower potentials and pacemaker potentials recorded from longitudinal muscle and myenteric interstitial cells, respectively. Slow waves were comprised of 1st and 2nd components, and the latency for generating the 2nd component was decreased exponentially by elevating temperature, reaching a stable value of about 1 s above 32°C. The temperature coefficient was >2 for the frequency, dV/dt and latency of the 2nd component, about 1.7 for the duration and about 1 for amplitude. Potassium cyanide (KCN), an inhibitor of mitochondrial metabolic activity, reduced the frequency and duration of slow waves, with no alteration to other parameters (amplitude, dV/dt, latency). In the presence of 30 μM KCN, the temperature-dependency of the frequency of slow waves was diminished or abolished, while other parameters of slow waves remained unaltered. These results indicate that in slow waves the frequency may be related to metabolic activities, while the temperature-dependent changes in the dV/dt, latency for the 2nd component and duration of slow waves are produced largely by mechanisms other than metabolic activity.

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Section: Introductionmentioning

confidence: 91%

Metabolic component of the temperature-sensitivity of slow waves recorded from gastric muscle of the guinea-pig

Nakamura

Kito

Hashitani

et al. 2006

J. Smooth Muscle Res.

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“…In guinea-pig, gastric fundus preparations exhibit tonic contractile force, which is combined with regular spike discharge. Antrum preparations, on the other hand, contract rhythmically, each phasic contraction being induced by a slow wave of depolarization which may have superimposed a multispike complex (Golenhofen, von Loh & Milenov, 1970). Both types of activity in the guinea-pig stomach are unaffected by tetrodotoxin (TTX) and atropine.…”

Section: Introductionmentioning

confidence: 99%

Characterization of membrane currents in single smooth muscle cells from the guinea‐pig gastric antrum.

Noack

Deitmer

Lammel

1992

The Journal of Physiology

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SUMMARY1. Smooth muscle cells, enzymatically isolated from the antrum of the guinea-pig stomach, were voltage clamped at room temperature using the whole-cell patch clamp technique. In physiological salt solution (PSS), step depolarization from a holding potential of -90 mV elicited inward calcium current (ICa) followed and superimposed by outward potassium current.2. Outward current was divided into components depending on the presence of extracellular Ca2+ and others which were not activated as a result of Ca2+ influx.Ca2+-dependent components were (1) 3. It. activated with a threshold around -30 mV, was fully available at -90 mV and completely inactivated at -10 mV. The time course of both activation and inactivation of Ito at different potentials could be described by single exponential functions. Time constants of activation decreased from 35 ms at -10 mV to 10 ms at + 40 mV. The time constant of inactivation was about 2 s and only weakly voltage dependent. Time constants for exponentially developing recovery from inactivation

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“…It is tempting to compare this type of activity to the "hourrhythm" known from the guinea-pig stomach (7). Activity complexes in the cat colon usually are propagated in an aborad direction, but we don't know yet whether they propel colonic contents.…”

Section: Effect Of Time Of Daymentioning

confidence: 98%

Circadian rhythm of colonic motility in the cat

Wienbeck

Kreuzpaintner²

1976

Res. Exp. Med.

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Since circadian patterns of colonic motility are largely unknown the electrical activity of the colon musculature was recorded in 6 unanesthetized cats during day and night. All parts of the colon exhibited 6 patterns of electrical activity: spikes, oscillations, omnipresent regular slow waves, and three composite patterns, i.e. a minute-rhythmic activity, activity complexes of 1 to 18 minute duration and a nyctohemeral pattern. The circadian rhythm was different between the proximal and distal colon resulting in activity gradients. These were directed in an aborad direction from 7 to 9 a.m. and from 9 p.m. to midnight. Most of the defecations of the 6 cats occured in the late evening until 1 a.m. Spike activity of the distal colon predominated from 3 to 4 a.m. and from 11 a.m. to 5 p.m. It is concluded that a circadian rhythm exists in the motility of the cat colon. Differences in the activity between the proximal and the distal colon and resulting activity gradients may offer an explanation for the influences of the time of day on the timing of defecations.

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Elektrophysiologische Untersuchungen zur Spontanaktivität isolierter Muskelpräparate aus verschiedenen Abschnitten des Meerschweinchen-Magens

Cited by 25 publications

References 15 publications

Metabolic component of the temperature-sensitivity of slow waves recorded from gastric muscle of the guinea-pig

Metabolic component of the temperature-sensitivity of slow waves recorded from gastric muscle of the guinea-pig

Characterization of membrane currents in single smooth muscle cells from the guinea‐pig gastric antrum.

Circadian rhythm of colonic motility in the cat

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