AT1 receptors mediate contractile effects of Angiotensin II on mouse colon

Risultato della ricerca: Other

Abstract

Angiotensin II (Ang II) is a potent smooth muscle contractile neurohumoral agonist via interaction with AT1 and AT2 receptors. Although these receptors are well expressed in the gut, very little research has been devoted to analysed the physiological role played by Ang II (and its receptors) in the regulation of gastrointestinal motility. The effects of Ang II on mouse proximal and distal colon contractility, the receptor subtypes involved were investigated in vitro, using the organ bath technique. Longitudinally-oriented segments from mouse proximal and distal colon displayed ongoing contractile activity, characterized by phasic contractions. Ang II induced a concentration-dependent muscular contraction in both preparations, reduced by the neural blocker, tetrodotoxin, by the AT1 receptor antagonist, losartan, but not affected by the AT2 receptor antagonist, PD123319. SR140333, a tachykinin NK1 receptor antagonist, antagonized the excitatory effects induced by Ang II in the proximal but not in the distal colon, whilst atropine, muscarinic receptor antagonist, antagonized the contractile effects to Ang II only in the distal colon. In conclusion, in the murine colon Ang II positively modulates the spontaneous contractile activity, via activation of post-junctional AT1 receptors and of pre-junctional AT1 receptors on tachykinergic neurons in the proximal colon and on cholinergic neurons in the distal colon, regulating neurotransmitter release.
Lingua originaleEnglish
Numero di pagine1
Stato di pubblicazionePublished - 2011

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Angiotensin II
Colon
Tachykinin Receptors
Angiotensin Receptors
Cholinergic Neurons
Muscarinic Antagonists
Gastrointestinal Motility
Losartan
Muscarinic Receptors
Muscle Contraction
Baths
Atropine
Smooth Muscle
Neurotransmitter Agents
Neurons
Research

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title = "AT1 receptors mediate contractile effects of Angiotensin II on mouse colon",
abstract = "Angiotensin II (Ang II) is a potent smooth muscle contractile neurohumoral agonist via interaction with AT1 and AT2 receptors. Although these receptors are well expressed in the gut, very little research has been devoted to analysed the physiological role played by Ang II (and its receptors) in the regulation of gastrointestinal motility. The effects of Ang II on mouse proximal and distal colon contractility, the receptor subtypes involved were investigated in vitro, using the organ bath technique. Longitudinally-oriented segments from mouse proximal and distal colon displayed ongoing contractile activity, characterized by phasic contractions. Ang II induced a concentration-dependent muscular contraction in both preparations, reduced by the neural blocker, tetrodotoxin, by the AT1 receptor antagonist, losartan, but not affected by the AT2 receptor antagonist, PD123319. SR140333, a tachykinin NK1 receptor antagonist, antagonized the excitatory effects induced by Ang II in the proximal but not in the distal colon, whilst atropine, muscarinic receptor antagonist, antagonized the contractile effects to Ang II only in the distal colon. In conclusion, in the murine colon Ang II positively modulates the spontaneous contractile activity, via activation of post-junctional AT1 receptors and of pre-junctional AT1 receptors on tachykinergic neurons in the proximal colon and on cholinergic neurons in the distal colon, regulating neurotransmitter release.",
keywords = "Angiotensin II",
author = "Mariangela Mastropaolo and Serio, {Rosa Maria} and Flavia Mule' and Zizzo, {Maria Grazia}",
year = "2011",
language = "English",

}

TY - CONF

T1 - AT1 receptors mediate contractile effects of Angiotensin II on mouse colon

AU - Mastropaolo, Mariangela

AU - Serio, Rosa Maria

AU - Mule', Flavia

AU - Zizzo, Maria Grazia

PY - 2011

Y1 - 2011

N2 - Angiotensin II (Ang II) is a potent smooth muscle contractile neurohumoral agonist via interaction with AT1 and AT2 receptors. Although these receptors are well expressed in the gut, very little research has been devoted to analysed the physiological role played by Ang II (and its receptors) in the regulation of gastrointestinal motility. The effects of Ang II on mouse proximal and distal colon contractility, the receptor subtypes involved were investigated in vitro, using the organ bath technique. Longitudinally-oriented segments from mouse proximal and distal colon displayed ongoing contractile activity, characterized by phasic contractions. Ang II induced a concentration-dependent muscular contraction in both preparations, reduced by the neural blocker, tetrodotoxin, by the AT1 receptor antagonist, losartan, but not affected by the AT2 receptor antagonist, PD123319. SR140333, a tachykinin NK1 receptor antagonist, antagonized the excitatory effects induced by Ang II in the proximal but not in the distal colon, whilst atropine, muscarinic receptor antagonist, antagonized the contractile effects to Ang II only in the distal colon. In conclusion, in the murine colon Ang II positively modulates the spontaneous contractile activity, via activation of post-junctional AT1 receptors and of pre-junctional AT1 receptors on tachykinergic neurons in the proximal colon and on cholinergic neurons in the distal colon, regulating neurotransmitter release.

AB - Angiotensin II (Ang II) is a potent smooth muscle contractile neurohumoral agonist via interaction with AT1 and AT2 receptors. Although these receptors are well expressed in the gut, very little research has been devoted to analysed the physiological role played by Ang II (and its receptors) in the regulation of gastrointestinal motility. The effects of Ang II on mouse proximal and distal colon contractility, the receptor subtypes involved were investigated in vitro, using the organ bath technique. Longitudinally-oriented segments from mouse proximal and distal colon displayed ongoing contractile activity, characterized by phasic contractions. Ang II induced a concentration-dependent muscular contraction in both preparations, reduced by the neural blocker, tetrodotoxin, by the AT1 receptor antagonist, losartan, but not affected by the AT2 receptor antagonist, PD123319. SR140333, a tachykinin NK1 receptor antagonist, antagonized the excitatory effects induced by Ang II in the proximal but not in the distal colon, whilst atropine, muscarinic receptor antagonist, antagonized the contractile effects to Ang II only in the distal colon. In conclusion, in the murine colon Ang II positively modulates the spontaneous contractile activity, via activation of post-junctional AT1 receptors and of pre-junctional AT1 receptors on tachykinergic neurons in the proximal colon and on cholinergic neurons in the distal colon, regulating neurotransmitter release.

KW - Angiotensin II

UR - http://hdl.handle.net/10447/62059

M3 - Other

ER -