Search results for " mouse colon"
showing 4 items of 4 documents
Novel evidences for a role of dopamine as modulator of intestinal motility: a study on mouse distal colon
2014
Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease. It has been classically considered that the pathological hallmarks of PD affect primarily the substantia nigra. Nevertheless, it has become increasingly evident that PD is a multicentric neurodegenerative process that affects several neuronal structures outside the substantia nigra, among which is the enteric nervous system (ENS). Pathological alterations within the ENS could be involved in the gastrointestinal (GI) dysfunction frequently encountered by PD patients. Dopamine (DA) seems to be a major candidate for the impairment of GI function in PD since its levels were found to be decrea…
Arginine vasopressin, via activation of post-junctional V1 receptors, induces contractile effects in mouse distal colon
2013
The aim of this study was to analyze whether arginine vasopressin (AVP) may be considered a modulator of intestinal motility. In this view, we evaluated, in vitro, the effects induced by exogenous administration of AVP on the contractility of mouse distal colon, the subtype(s) of receptor(s) activated and the action mechanism. Isometric recordings were performed on longitudinal and circular muscle strips of mouse distal colon. AVP (0.001 nM-100 nM) caused concentration-dependent contractile effects only on the longitudinal muscle, antagonized by the V1 receptor antagonist, V-1880. AVP-induced effect was not modified by tetrodotoxin, atropine and indomethacin. Contractile response to AVP was…
Angiotensin II contractile effects in mouse colon: role for pre- and post-junctional AT1A receptors
2013
Aim This study investigates whether a local renin–angiotensin system (RAS) exists in mouse colon and whether angiotensin II (Ang II) may play a role in the regulation of the contractile activity. Methods Isometric recordings were performed in vitro on the longitudinal muscle of mouse proximal and distal colon. Transcripts encoding for RAS components were investigated by RT-PCR. Results Ang II caused, in both preparations, a concentration-dependent contractile effect, antagonized by losartan, AT1 receptor antagonist, but not by PD123319, AT2 receptor antagonist. The combination of losartan plus PD123319 caused no change on the Ang II-induced contraction than losartan alone. Tetrodotoxin, neu…
Guanine-based purines affects the enteric cholinergic neurotransmission via a mechanism not involving membrane receptors
2011
Increasing evidence indicate that guanine-based purines, known as modulators of intracellular processes, can exert extracellular effects, raising the possibility of the existence of specific receptors for these compounds. We investigated if guaninebased purine receptors may be present in the rodent gastrointestinal tract modulating intestinal contractility, as the well known adenine-based purine receptors. Experiments were performed in vitro recording spontaneous and neurally-evoked contractile activity, as changes in isometric tension, in mouse distal colon circular muscle. Guanosine up to 3 mM or guanine up to 1 mM, did not affect the spontaneous mechanical activity, but they significantl…