The aim of this experiment was to determine the pharmacokinetics of hydrochloric idazoxan in deers plasma alter intramuscular （IM） dosing. Six clinical healthy Cervus nippon Temmincks were injected with the idazoxan...The aim of this experiment was to determine the pharmacokinetics of hydrochloric idazoxan in deers plasma alter intramuscular （IM） dosing. Six clinical healthy Cervus nippon Temmincks were injected with the idazoxan solution at the dose of 0.44 mg·kg-1. Eight mL blood sample was taken from a jugular vein and plasma was separated for drug determination by using liquid chromatography with tandem mass spectrometric detection. Idazoxan pharmacokinetic parameters were simulated by noncompartmental analyses. The results showed that the absorption and elimination of hydrochloric idazoxan in plasma was quick by route of administration, the half-lives of absorption （t1/2Ka） and elimination （t1/2Kc） were （0.2094 ± 0.0341） min, and （13.1842±0.2353） min, respectively, the area under the plasma drug concentration-time curve from 0 to ∞ （AUC） was （0.0700±0.0035） （mg·mL-1）. min the maximum concentration in the plasma （Cmax） was （0,0047±0.0005） mg.mL ＇, peaking at （12.4618±0.1198） rain after dosing. In conclusion, these data indicated that the kinetics of hydrochloric idazoxan were fitted to one compartment model with first order absorption, which was characterized by rapid drug action, and fast metabolism with few residue in the blood.展开更多
The nature of the binding site(s) involved in the insulin secretory activity of imidazoline compo- unds remains unclear. An imidazoline I2 binding site (I2BS) has been neglected since the classic I2 ligand, idazoxan, ...The nature of the binding site(s) involved in the insulin secretory activity of imidazoline compo- unds remains unclear. An imidazoline I2 binding site (I2BS) has been neglected since the classic I2 ligand, idazoxan, does not release insulin. Using the rabbit as an appropriate model for the study of this type of binding sites, we have tried to re-evaluate the effects of idazoxan, the selective I2 compound BU 224, and efaroxan on insulin secretion. Mimicking efaroxan, idazoxan and BU 224 potentiated insulin release from perifused islets in the presence of 8 mM glucose. In static incubation, insulin secretion induced by idazoxan and BU 224 exhibited both dose and glucose dependencies. ATP-sensitive K+ (KATP) channel blockade, though at a different site from the SUR1 receptor, with subsequent Ca2+ entry, mediates the insulin releasing effect of the three ligands. However, additional MAO independent intracellular steps in stimulus- secretion coupling linked to PKA and PKC activation are only involved in the effect of BU 224. Therefore, both an I2 related binding site at the channel level shared by the three ligands and a putative I3-intracellularly located binding site stimulated by BU 224 would be mediating insulin release by these compounds. In vivo experiments reassess the abilities of idazoxan and BU 224 to enhance glucose-induced insulin secretion and to elicit a modest blood glucose lowering response.展开更多
基金Supported by Post-doctoral Scientific Research of Heilongjiang Province (LBH-Q07016)
文摘The aim of this experiment was to determine the pharmacokinetics of hydrochloric idazoxan in deers plasma alter intramuscular （IM） dosing. Six clinical healthy Cervus nippon Temmincks were injected with the idazoxan solution at the dose of 0.44 mg·kg-1. Eight mL blood sample was taken from a jugular vein and plasma was separated for drug determination by using liquid chromatography with tandem mass spectrometric detection. Idazoxan pharmacokinetic parameters were simulated by noncompartmental analyses. The results showed that the absorption and elimination of hydrochloric idazoxan in plasma was quick by route of administration, the half-lives of absorption （t1/2Ka） and elimination （t1/2Kc） were （0.2094 ± 0.0341） min, and （13.1842±0.2353） min, respectively, the area under the plasma drug concentration-time curve from 0 to ∞ （AUC） was （0.0700±0.0035） （mg·mL-1）. min the maximum concentration in the plasma （Cmax） was （0,0047±0.0005） mg.mL ＇, peaking at （12.4618±0.1198） rain after dosing. In conclusion, these data indicated that the kinetics of hydrochloric idazoxan were fitted to one compartment model with first order absorption, which was characterized by rapid drug action, and fast metabolism with few residue in the blood.
文摘The nature of the binding site(s) involved in the insulin secretory activity of imidazoline compo- unds remains unclear. An imidazoline I2 binding site (I2BS) has been neglected since the classic I2 ligand, idazoxan, does not release insulin. Using the rabbit as an appropriate model for the study of this type of binding sites, we have tried to re-evaluate the effects of idazoxan, the selective I2 compound BU 224, and efaroxan on insulin secretion. Mimicking efaroxan, idazoxan and BU 224 potentiated insulin release from perifused islets in the presence of 8 mM glucose. In static incubation, insulin secretion induced by idazoxan and BU 224 exhibited both dose and glucose dependencies. ATP-sensitive K+ (KATP) channel blockade, though at a different site from the SUR1 receptor, with subsequent Ca2+ entry, mediates the insulin releasing effect of the three ligands. However, additional MAO independent intracellular steps in stimulus- secretion coupling linked to PKA and PKC activation are only involved in the effect of BU 224. Therefore, both an I2 related binding site at the channel level shared by the three ligands and a putative I3-intracellularly located binding site stimulated by BU 224 would be mediating insulin release by these compounds. In vivo experiments reassess the abilities of idazoxan and BU 224 to enhance glucose-induced insulin secretion and to elicit a modest blood glucose lowering response.
