Free and Conjugated Catecholamines in Digestive Tissues of Rats

Gaudin, Christophe; Ruget, G; Selz, Françoise; Cuche, Jean-Louis

doi:10.1097/00004872-198610000-00077

Cited by 2 publications

(2 citation statements)

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“…Previous reports showed that a large proportion of peripheral CA in blood or urine exists as a conjugated form that is biologically inactive (15,54). Previous reports showed that a large proportion of peripheral CA in blood or urine exists as a conjugated form that is biologically inactive (15,54).…”

Section: Presence Of Considerable Amounts Of Catecholamines In the Lumentioning

confidence: 99%

Critical role of gut microbiota in the production of biologically active, free catecholamines in the gut lumen of mice

Asano

Hiramoto

Nishino

et al. 2012

American Journal of Physiology-Gastrointestinal and Liver Physi

518

379

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There is increasing interest in the bidirectional communication between the mammalian host and prokaryotic cells. Catecholamines (CA), candidate molecules for such communication, are presumed to play an important role in the gut lumen; however, available evidence is limited because of the lack of actual data about luminal CA. This study evaluated luminal CA levels in the gastrointestinal tract and elucidated the involvement of gut microbiota in the generation of luminal CA by comparing the findings among specific pathogen-free mice (SPF-M), germ-free mice (GF-M), and gnotobiotic mice. Substantial levels of free dopamine and norepinephrine were identified in the gut lumen of SPF-M. The free CA levels in the gut lumen were lower in GF-M than in SPF-M. The majority of CA was a biologically active, free form in SPF-M, whereas it was a biologically inactive, conjugated form in GF-M. The association of GF-M with either Clostridium species or SPF fecal flora, both of which have abundant β-glucuronidase activity, resulted in the drastic elevation of free CA. The inoculation of E. coli strain into GF-M induced a substantial amount of free CA, but the inoculation of its mutant strain deficient in the β-glucuronidase gene did not. The intraluminal administration of DA increased colonic water absorption in an in vivo ligated loop model of SPF-M, thus suggesting that luminal DA plays a role as a proabsorptive modulator of water transport in the colon. These results indicate that gut microbiota play a critical role in the generation of free CA in the gut lumen.

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Section: Presence Of Considerable Amounts Of Catecholamines In the Lumentioning

confidence: 99%

Critical role of gut microbiota in the production of biologically active, free catecholamines in the gut lumen of mice

Asano

Hiramoto

Nishino

et al. 2012

American Journal of Physiology-Gastrointestinal and Liver Physi

518

379

View full text Add to dashboard Cite

show abstract

“…Dopamine is present in the human nervous system and acts directly on specific central and peripheral receptors [1]. There are significant amounts of dopamine in the gastrointestinal tract, accounting for up to 20% of the free catecholamine content in the stomach [2]. Studies in dogs and volunteers have shown that dopamine decreases stomach muscle tone and it has been proposed as a possible neurotransmitter in gastric relaxation [3, 4].…”

Section: Introductionmentioning

confidence: 99%

Dopamine delays gastric emptying and prolongs orocaecal transit time in volunteers

1999

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Dopamine decreases gastric tone and may therefore influence gastrointestinal motility. The aim of this investigation was to study the effects of a continuous infusion of dopamine on gastric emptying and orocaecal transit time. Nine healthy male volunteers were studied on two occasions in a randomized order. All volunteers received on separate days a continuous infusion of dopamine 5 micrograms kg-1 min-1 on one occasion and normal saline on the other occasion. Gastric emptying was measured by the paracetamol absorption test and orocaecal transit time by the hydrogen breath test. During the dopamine infusion the area under the paracetamol concentration curve was significantly smaller than during control conditions (P = 0.02). Orocaecal transit time was prolonged during the dopamine infusion (P = 0.02). Dopamine delays gastric emptying and prolongs orocaecal transit time.

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Free and Conjugated Catecholamines in Digestive Tissues of Rats

Cited by 2 publications

References 0 publications

Critical role of gut microbiota in the production of biologically active, free catecholamines in the gut lumen of mice

Critical role of gut microbiota in the production of biologically active, free catecholamines in the gut lumen of mice

Dopamine delays gastric emptying and prolongs orocaecal transit time in volunteers

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