caa a22 4500 463237404 CHVBK 20180405153302.0 cr unu---uuuuu 170326e20070401xx s 000 0 eng 10.1007/s11259-006-3414-1 doi (NATIONALLICENCE)springer-10.1007/s11259-006-3414-1 Effects of Brimonidine Ingestion on Cardiovascular Responses and Renal Function in Conscious Dogs [Elektronische Daten] [S. Suwanwipat, C. Buranakarl, N. Chaiyabutr] The effects of brimonidine, an α2-adrenoceptor agonist, on blood pressure, heart rate, respiratory rate, renal function and some blood parameters were investigated in 10 dogs. Dogs were divided into two groups, low dose (LD; 0.2 mg/kg) and high dose (HD; 0.5 mg/kg) of brimonidine given orally. The α2-adrenergic antagonist yohimbine hydrochloride was injected to dogs at a dose of 0.1 mg/kg in both groups at the fifth hour after brimonidine administration. The results demonstrated that after administration of brimonidine, mean arterial blood pressure decreased dramatically at 2 h by 23% and 20% in LD and HD groups, respectively. Heart rate was decreased in a similar manner and both remained low at 5 h after brimonidine administration. Respiratory rate was decreased by 50%, while the electrocardiogram showed prolongation of the PR interval. Glomerular filtration rate (GFR) and effective renal blood flow were reduced when measured at 4 h after brimonidine ingestion in both groups, but the effect was more pronounced in the LD group. Brimonidine caused natriuresis and kaliuresis in both LD and HD groups. The packed cell volume was decreased and hyperglycaemia was detected. Most of the effects can be reversed completely after administration of yohimbine. However, yohombine can restore GFR only partially. These data suggest that brimonidine caused cardiovascular and respiratory depression. The adverse effects of this drug can be antagonized by yohimbine, suggesting that these effects were mediated via the α2-adrenoceptor. Springer Science + Business Media, Inc., 2007 brimonidine nationallicence yohimbine nationallicence adrenoceptor nationallicence blood pressure nationallicence glomerular filtration rate nationallicence dog nationallicence $$ C_{{\rm H_{2}O}} $$ : free water clearance nationallicence C osm : osmolar clearance nationallicence ECG : electrocardiography/electrocardiogram nationallicence ERBF : effective renal blood flow nationallicence ERPF : effective renal plasma flow nationallicence FECa : fractional excretion of Ca2+ nationallicence FECl : fractional excretion of Cl− nationallicence FEe : electrolytes nationallicence FEK : fractional excretion of K+ nationallicence FENa : fractional excretion of Na+ nationallicence FEPi : fractional excretion of inorganic phosphate nationallicence FF : filtration fraction nationallicence GFR : glomerular filtration rate nationallicence HD : high dose nationallicence LD : low dose nationallicence MAP : mean arterial pressure nationallicence NTS : nucleus tractus solitarius nationallicence PAH : para-aminohippuric acid nationallicence PCV : packed cell volume nationallicence RR : respiratory rate nationallicence RT : rectal temperature nationallicence RVLM : rostral ventrolateral medial nationallicence RVR : renal vascular resistance nationallicence TS : total solids nationallicence V : urine flow rate nationallicence Suwanwipat S. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand aut Buranakarl C. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand aut Chaiyabutr N. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand aut Veterinary Research Communications Kluwer Academic Publishers 31/3(2007-04-01), 323-334 0165-7380 31:3<323 2007 31 11259 https://doi.org/10.1007/s11259-006-3414-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11259-006-3414-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Suwanwipat S. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand aut NATIONALLICENCE 700 1- Buranakarl C. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand aut NATIONALLICENCE 700 1- Chaiyabutr N. Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand aut NATIONALLICENCE 773 0- Veterinary Research Communications Kluwer Academic Publishers 31/3(2007-04-01), 323-334 0165-7380 31:3<323 2007 31 11259 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer