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Neurotensin Changes Propulsive Activity into a Segmental Motor Pattern in the Rat Colon.

Li H, Chen JH, Yang Z, Huang M, Yu Y, Tan S, Luo H, Huizinga JD - J Neurogastroenterol Motil (2016)

Bottom Line: High concentrations given without prior additions of low concentrations did not evoke the segmental motor pattern.These actions occurred when neurotensin was given in the bath solution or intraluminally.The segmental motor pattern evoked by neurotensin was inhibited by the neural conduction blocker lidocaine.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, Hubei Province, China.

ABSTRACT

Background/aims: Neurotensin is a gut-brain peptide with both inhibitory and excitatory actions on the colonic musculature; our objective was to understand the implications of this for motor patterns occurring in the intact colon of the rat.

Methods: The effects of neurotensin with concentrations ranging from 0.1-100 nM were studied in the intact rat colon in vitro, by investigating spatio-temporal maps created from video recordings of colonic motility before and after neurotensin.

Results: Low concentration of neurotensin (0.1-1 nM) inhibited propagating long distance contractions and rhythmic propagating motor complexes; in its place a slow propagating rhythmic segmental motor pattern developed. The neurotensin receptor 1 antagonist SR-48692 prevented the development of the segmental motor pattern. Higher concentrations of neurotensin (10 nM and 100 nM) were capable of restoring long distance contraction activity and inhibiting the segmental activity. The slow propagating segmental contraction showed a rhythmic contraction-- relaxation cycle at the slow wave frequency originating from the interstitial cells of Cajal associated with the myenteric plexus pacemaker. High concentrations given without prior additions of low concentrations did not evoke the segmental motor pattern. These actions occurred when neurotensin was given in the bath solution or intraluminally. The segmental motor pattern evoked by neurotensin was inhibited by the neural conduction blocker lidocaine.

Conclusions: Neurotensin (0.1-1 nM) inhibits the dominant propulsive motor patterns of the colon and a distinct motor pattern of rhythmic slow propagating segmental contractions develops. This motor pattern has the hallmarks of haustral boundary contractions.

No MeSH data available.


Related in: MedlinePlus

The segmental nature of the neurotensin induced contractions. In sequential video images (time between [A] and [B] is 88 seconds and time between [B] and [C] is 14 seconds) the segmental nature of the contractions is seen. The colon is divided into segments. The contractions are also seen to propagate and are seen to periodically relax, given the contractions an on/off/ on/off appearance. See Supplementary Video 1. The activity occurred in the presence of neurotensin (0.5 nM). (D) The spatio-temporal map (same as Fig. 1C) relates to the video images. The video images are moments in time, taken from Supplementary Video 1 whose spatiotemporal map is figure (D). The segmental nature can also be shown in an amplitude profile (E) made at the vertical line.
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f2-jnm-22-517: The segmental nature of the neurotensin induced contractions. In sequential video images (time between [A] and [B] is 88 seconds and time between [B] and [C] is 14 seconds) the segmental nature of the contractions is seen. The colon is divided into segments. The contractions are also seen to propagate and are seen to periodically relax, given the contractions an on/off/ on/off appearance. See Supplementary Video 1. The activity occurred in the presence of neurotensin (0.5 nM). (D) The spatio-temporal map (same as Fig. 1C) relates to the video images. The video images are moments in time, taken from Supplementary Video 1 whose spatiotemporal map is figure (D). The segmental nature can also be shown in an amplitude profile (E) made at the vertical line.

Mentions: Neurotensin was administered into the bath solution in a cumulative manner up to 0.1, 0.5, and 1.0 nM (n = 21). LDCs, always starting in the proximal colon, were inhibited in a dose dependent manner, assessed by the number of colons that lost all LDC activity (from 86% to 38%) and a significant reduction in frequency in the remainder (Fig. 1–3 and Table 1). Neurotensin also inhibited RPMC activity, a motor activity occurring in the mid-distal colon (Table 2). Replacing these 2 propulsive motor patterns22 emerged a motor pattern that originated in the proximal colon and propagated slowly as a rhythmically contracting circular muscle ring contraction (Fig. 1–3 and Table 3). The slow propagating contractions divided the colon into segments or pockets, and hence were called slow propagating segmental contractions (Fig. 2 and Supplementary Video 1). The slow propagating segmental contractions did not run from proximal to distal with a relatively constant force: rhythmic increases and decreases in amplitude occurred at a frequency of 1.6 ± 0.3 cpm. In addition, ripple activity often occurred within the pockets, often propagating retrogradely (Supplementary Video 1). Ripple activity is a low amplitude rhythmic motor pattern of the small intestine at 10–14 cpm.22


Neurotensin Changes Propulsive Activity into a Segmental Motor Pattern in the Rat Colon.

Li H, Chen JH, Yang Z, Huang M, Yu Y, Tan S, Luo H, Huizinga JD - J Neurogastroenterol Motil (2016)

The segmental nature of the neurotensin induced contractions. In sequential video images (time between [A] and [B] is 88 seconds and time between [B] and [C] is 14 seconds) the segmental nature of the contractions is seen. The colon is divided into segments. The contractions are also seen to propagate and are seen to periodically relax, given the contractions an on/off/ on/off appearance. See Supplementary Video 1. The activity occurred in the presence of neurotensin (0.5 nM). (D) The spatio-temporal map (same as Fig. 1C) relates to the video images. The video images are moments in time, taken from Supplementary Video 1 whose spatiotemporal map is figure (D). The segmental nature can also be shown in an amplitude profile (E) made at the vertical line.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4930308&req=5

f2-jnm-22-517: The segmental nature of the neurotensin induced contractions. In sequential video images (time between [A] and [B] is 88 seconds and time between [B] and [C] is 14 seconds) the segmental nature of the contractions is seen. The colon is divided into segments. The contractions are also seen to propagate and are seen to periodically relax, given the contractions an on/off/ on/off appearance. See Supplementary Video 1. The activity occurred in the presence of neurotensin (0.5 nM). (D) The spatio-temporal map (same as Fig. 1C) relates to the video images. The video images are moments in time, taken from Supplementary Video 1 whose spatiotemporal map is figure (D). The segmental nature can also be shown in an amplitude profile (E) made at the vertical line.
Mentions: Neurotensin was administered into the bath solution in a cumulative manner up to 0.1, 0.5, and 1.0 nM (n = 21). LDCs, always starting in the proximal colon, were inhibited in a dose dependent manner, assessed by the number of colons that lost all LDC activity (from 86% to 38%) and a significant reduction in frequency in the remainder (Fig. 1–3 and Table 1). Neurotensin also inhibited RPMC activity, a motor activity occurring in the mid-distal colon (Table 2). Replacing these 2 propulsive motor patterns22 emerged a motor pattern that originated in the proximal colon and propagated slowly as a rhythmically contracting circular muscle ring contraction (Fig. 1–3 and Table 3). The slow propagating contractions divided the colon into segments or pockets, and hence were called slow propagating segmental contractions (Fig. 2 and Supplementary Video 1). The slow propagating segmental contractions did not run from proximal to distal with a relatively constant force: rhythmic increases and decreases in amplitude occurred at a frequency of 1.6 ± 0.3 cpm. In addition, ripple activity often occurred within the pockets, often propagating retrogradely (Supplementary Video 1). Ripple activity is a low amplitude rhythmic motor pattern of the small intestine at 10–14 cpm.22

Bottom Line: High concentrations given without prior additions of low concentrations did not evoke the segmental motor pattern.These actions occurred when neurotensin was given in the bath solution or intraluminally.The segmental motor pattern evoked by neurotensin was inhibited by the neural conduction blocker lidocaine.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, Hubei Province, China.

ABSTRACT

Background/aims: Neurotensin is a gut-brain peptide with both inhibitory and excitatory actions on the colonic musculature; our objective was to understand the implications of this for motor patterns occurring in the intact colon of the rat.

Methods: The effects of neurotensin with concentrations ranging from 0.1-100 nM were studied in the intact rat colon in vitro, by investigating spatio-temporal maps created from video recordings of colonic motility before and after neurotensin.

Results: Low concentration of neurotensin (0.1-1 nM) inhibited propagating long distance contractions and rhythmic propagating motor complexes; in its place a slow propagating rhythmic segmental motor pattern developed. The neurotensin receptor 1 antagonist SR-48692 prevented the development of the segmental motor pattern. Higher concentrations of neurotensin (10 nM and 100 nM) were capable of restoring long distance contraction activity and inhibiting the segmental activity. The slow propagating segmental contraction showed a rhythmic contraction-- relaxation cycle at the slow wave frequency originating from the interstitial cells of Cajal associated with the myenteric plexus pacemaker. High concentrations given without prior additions of low concentrations did not evoke the segmental motor pattern. These actions occurred when neurotensin was given in the bath solution or intraluminally. The segmental motor pattern evoked by neurotensin was inhibited by the neural conduction blocker lidocaine.

Conclusions: Neurotensin (0.1-1 nM) inhibits the dominant propulsive motor patterns of the colon and a distinct motor pattern of rhythmic slow propagating segmental contractions develops. This motor pattern has the hallmarks of haustral boundary contractions.

No MeSH data available.


Related in: MedlinePlus