Romain Lefebvre | Ghent University (original) (raw)
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Papers by Romain Lefebvre
British Journal of Pharmacology, Nov 1, 2003
Equine Veterinary Journal, 2015
Dopamine Receptor Agonists, 1984
In the last 20 years there has been increasing interest in the effects of dopamine both in the CN... more In the last 20 years there has been increasing interest in the effects of dopamine both in the CNS and in the periphery. Moreover, much work has been done to elucidate which receptors are involved in these effects.
Equine Veterinary Journal, 2008
Summary Reasons for performing study: Increased plasma (5‐HT) concentrations are reported in hors... more Summary Reasons for performing study: Increased plasma (5‐HT) concentrations are reported in horses predisposed to develop laminitis and after i.v. infusion of endotoxins. In the equine jejunum contractile 5‐HT1A‐like receptors show tachyphylaxia upon prolonged activation with 5‐HT. Therefore, increased systemic 5‐HT release in colic horses could play a possible role in the pathophysiology of ileus. Objective: To investigate possible increased systemic release of 5‐HT in colic horses with compromised bowel and to identify the source of 5‐HT overload. Methods: Concentrations of 5‐HT were determined in plasma and peritoneal fluid (PF) of healthy horses (n = 10), strangulating small intestinal colic horses (n = 18), nonsurgical colic horses (n = 10) and cryptorchid stallions (n = 6). It was attempted to identify the source of 5‐HT overload by comparing the blood and PF 5‐HT concentrations within horses and by assessing the in vivo platelet activation through determination of the β‐thro...
Vlaams Diergeneeskundig Tijdschrift, 2006
Tijdschrift Voor Geneeskunde, 1992
American Journal of Noninvasive Cardiology, 1991
Neurogastroenterology & Motility, 2017
Annals of Nutrition and Metabolism, 2001
Background: Bile excretion is obstructed in children with extrahepatic bile duct atresia (EHBA) r... more Background: Bile excretion is obstructed in children with extrahepatic bile duct atresia (EHBA) resulting in fat malabsorption and disturbed lipid metabolism. Aim: Investigate if the bile duct ligated rat exhibits similar deviations as patients with EHBA under different feeding conditions. Methods: 6 bile duct ligated Wistar rats and 12 matched paired controls were randomised over 3 feeding groups. Rats were killed 16 or 30 days postsurgery. Faeces, blood and livers were collected. Fat absorption was evaluated, markers for cholestasis and the fatty acid composition of serum phospholipids (PL) and cholesterol esters (CE) were determined. Fatty acid desaturation activities in liver microsomes were measured. Results: Cholestatic bile duct ligated rats have a lower fat absorption coefficient and a lower fraction of 18:2n–6 and 18:3n–3 in serum triglycerides than their controls. This demonstrates that bile duct ligated rats suffer from fat malabsorption. In contrast to the observations i...
Neurogastroenterology & Motility, 2017
BackgroundIn the gastrointestinal tract of several species, facilitating 5‐HT4 receptors were pro... more BackgroundIn the gastrointestinal tract of several species, facilitating 5‐HT4 receptors were proposed on myenteric cholinergic neurons innervating smooth muscle by in vitro study of the effect of the selective 5‐HT4 receptor agonist prucalopride on submaximal cholinergic contractions. This was not yet established in the murine gastrointestinal tract.MethodsIn circular smooth muscle strips from murine fundus, jejunum and colon, contractions were induced by electrical field stimulation in the presence of guanethidine, L‐NAME and for colon also MRS 2500. Submaximal contractions were induced to study the influence of prucalopride.Key ResultsElectrical field stimulation at reduced voltage induced reproducible submaximal neurogenic and cholinergic contractions as the contractions were abolished by tetrodotoxin and atropine. Hexamethonium had no systematic inhibitory effect but mecamylamine reduced the responses, suggesting that part of the cholinergic response is due to activation of pre...
Acta Gastro-enterologica Belgica, 2013
European Journal of Pharmacology, Sep 1, 1986
The emetic and antiemetic effects of opioid agonists were studied in awake dogs. The mu-agonists ... more The emetic and antiemetic effects of opioid agonists were studied in awake dogs. The mu-agonists morphine, fentanyl and methadone, in sedative doses, prevented the emetic response to apomorphine and copper sulphate; only morphine induced emesis, at doses lower than those required to prevent emesis. The delta-agonist [D-Ala2,Met5]enkephalinamide (DALA) and [Leu5]enkephalin induced emesis in some of the dogs studied but had no antiemetic activity. The kappa-agonists bremazocine and ethylketocyclazocine (EKC) did not induce emesis but, at sedative doses, prevented the emetic response to apomorphine. The emetic effect of DALA was antagonized by naloxone in some dogs; the antiemetic effect of morphine, bremazocine and EKC was blocked by both naloxone and MR 2266. The non-opioid sedatives diazepam, phenobarbital and xylazine, administered in sedative doses, did not prevent apomorphine-induced emesis. Our results suggest that a delta-receptor is involved in the emetic effect and a mu- and/or or kappa-receptor in the antiemetic effect of opioids.
European Journal of Pharmacology, Apr 1, 1992
European Journal of Clinical Pharmacology, Jun 1, 1991
European Journal of Clinical Pharmacology, May 1, 1992
British Journal of Pharmacology, Nov 1, 2003
Equine Veterinary Journal, 2015
Dopamine Receptor Agonists, 1984
In the last 20 years there has been increasing interest in the effects of dopamine both in the CN... more In the last 20 years there has been increasing interest in the effects of dopamine both in the CNS and in the periphery. Moreover, much work has been done to elucidate which receptors are involved in these effects.
Equine Veterinary Journal, 2008
Summary Reasons for performing study: Increased plasma (5‐HT) concentrations are reported in hors... more Summary Reasons for performing study: Increased plasma (5‐HT) concentrations are reported in horses predisposed to develop laminitis and after i.v. infusion of endotoxins. In the equine jejunum contractile 5‐HT1A‐like receptors show tachyphylaxia upon prolonged activation with 5‐HT. Therefore, increased systemic 5‐HT release in colic horses could play a possible role in the pathophysiology of ileus. Objective: To investigate possible increased systemic release of 5‐HT in colic horses with compromised bowel and to identify the source of 5‐HT overload. Methods: Concentrations of 5‐HT were determined in plasma and peritoneal fluid (PF) of healthy horses (n = 10), strangulating small intestinal colic horses (n = 18), nonsurgical colic horses (n = 10) and cryptorchid stallions (n = 6). It was attempted to identify the source of 5‐HT overload by comparing the blood and PF 5‐HT concentrations within horses and by assessing the in vivo platelet activation through determination of the β‐thro...
Vlaams Diergeneeskundig Tijdschrift, 2006
Tijdschrift Voor Geneeskunde, 1992
American Journal of Noninvasive Cardiology, 1991
Neurogastroenterology & Motility, 2017
Annals of Nutrition and Metabolism, 2001
Background: Bile excretion is obstructed in children with extrahepatic bile duct atresia (EHBA) r... more Background: Bile excretion is obstructed in children with extrahepatic bile duct atresia (EHBA) resulting in fat malabsorption and disturbed lipid metabolism. Aim: Investigate if the bile duct ligated rat exhibits similar deviations as patients with EHBA under different feeding conditions. Methods: 6 bile duct ligated Wistar rats and 12 matched paired controls were randomised over 3 feeding groups. Rats were killed 16 or 30 days postsurgery. Faeces, blood and livers were collected. Fat absorption was evaluated, markers for cholestasis and the fatty acid composition of serum phospholipids (PL) and cholesterol esters (CE) were determined. Fatty acid desaturation activities in liver microsomes were measured. Results: Cholestatic bile duct ligated rats have a lower fat absorption coefficient and a lower fraction of 18:2n–6 and 18:3n–3 in serum triglycerides than their controls. This demonstrates that bile duct ligated rats suffer from fat malabsorption. In contrast to the observations i...
Neurogastroenterology & Motility, 2017
BackgroundIn the gastrointestinal tract of several species, facilitating 5‐HT4 receptors were pro... more BackgroundIn the gastrointestinal tract of several species, facilitating 5‐HT4 receptors were proposed on myenteric cholinergic neurons innervating smooth muscle by in vitro study of the effect of the selective 5‐HT4 receptor agonist prucalopride on submaximal cholinergic contractions. This was not yet established in the murine gastrointestinal tract.MethodsIn circular smooth muscle strips from murine fundus, jejunum and colon, contractions were induced by electrical field stimulation in the presence of guanethidine, L‐NAME and for colon also MRS 2500. Submaximal contractions were induced to study the influence of prucalopride.Key ResultsElectrical field stimulation at reduced voltage induced reproducible submaximal neurogenic and cholinergic contractions as the contractions were abolished by tetrodotoxin and atropine. Hexamethonium had no systematic inhibitory effect but mecamylamine reduced the responses, suggesting that part of the cholinergic response is due to activation of pre...
Acta Gastro-enterologica Belgica, 2013
European Journal of Pharmacology, Sep 1, 1986
The emetic and antiemetic effects of opioid agonists were studied in awake dogs. The mu-agonists ... more The emetic and antiemetic effects of opioid agonists were studied in awake dogs. The mu-agonists morphine, fentanyl and methadone, in sedative doses, prevented the emetic response to apomorphine and copper sulphate; only morphine induced emesis, at doses lower than those required to prevent emesis. The delta-agonist [D-Ala2,Met5]enkephalinamide (DALA) and [Leu5]enkephalin induced emesis in some of the dogs studied but had no antiemetic activity. The kappa-agonists bremazocine and ethylketocyclazocine (EKC) did not induce emesis but, at sedative doses, prevented the emetic response to apomorphine. The emetic effect of DALA was antagonized by naloxone in some dogs; the antiemetic effect of morphine, bremazocine and EKC was blocked by both naloxone and MR 2266. The non-opioid sedatives diazepam, phenobarbital and xylazine, administered in sedative doses, did not prevent apomorphine-induced emesis. Our results suggest that a delta-receptor is involved in the emetic effect and a mu- and/or or kappa-receptor in the antiemetic effect of opioids.
European Journal of Pharmacology, Apr 1, 1992
European Journal of Clinical Pharmacology, Jun 1, 1991
European Journal of Clinical Pharmacology, May 1, 1992