Reference : Cardiovascular Response to Intravenous Administration of 5-Hydroxytryptamine after Ty...
Scientific journals : Article
Life sciences : Veterinary medicine & animal health
Cardiovascular Response to Intravenous Administration of 5-Hydroxytryptamine after Type-2 Receptor Blockade, by Metrenperone, in Healthy Calves
Linden, Annick mailto [Université de Liège - ULg > Département des maladies infectieuses et parasitaires > Santé et pathologies de la faune sauvage >]
Desmecht, Daniel mailto [Université de Liège - ULg > Département de morphologie et pathologie > Pathologie spéciale et autopsies >]
Amory, Hélène mailto [Université de Liège - ULg > Département clinique des animaux de compagnie et des équidés > Médecine interne des équidés >]
Lekeux, Pierre mailto [Université de Liège - ULg > Département de sciences fonctionnelles > Physiologie >]
Veterinary Journal
Yes (verified by ORBi)
[en] Serotonin ; cattle
[en] The cardiovascular response to 5-hydroxytryptamine (5-HT) challenge has been previously described in cattle. Abrupt bradycardia, followed by tachycardia, triphasic systemic blood pressure response, and pulmonary hypertension were the major changes elicited by 5-HT. The purpose of the present study was to determine whether the cardiovascular response to 5-HT in calves was attributable to 5-HT2 receptors. A specific 5-HT2 antagonist (metrenperone, 0.05 mg/kg) was administered intramuscular to six unsedated Friesian calves 30 min before the animals were given a 5-min intravenous 5-HT infusion. Mean systemic arterial (SAP), mean pulmonary arterial (PAP), pulmonary capillary wedge (PW) pressures were obtained by means of fluid-filled catheters, and cardiac output (CO) was measured by the thermodilution technique. Heart rate, stroke volume, systemic (SVR) and pulmonary (PVR) vascular resistances were calculated. Administration of 5-HT after metrenperone induced a short-lasting period of severe bradycardia followed by tachycardia and increased CO. The systemic blood pressure response was exclusively hypotensive and associated with a decrease in SVR. Conversely, PAP, PW, and PVR were not modified by 5-HT administration. The results establish that 5-HT induced systemic as well as pulmonary hypertension is mediated through the activation of type-2 serotonergic or alpha-adrenergic receptors, or both. In contrast, neither apnoea, bradycardia and hypotension, nor the positive chronotropic effect induced by 5-HT in cattle are mediated through such receptors.
Researchers ; Professionals ; Students

File(s) associated to this reference

Fulltext file(s):

Restricted access
LindenA_TheVetJ_1999.pdfDemander un tiré à partPublisher postprint191.8 kBRequest copy

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.