Zhongguo yao li xue bao = Acta pharmacologica Sinica (Acta Pharmacol Sin)

Publications in this journal

• Article: Effect of somatostatin and its antagonist on morphine analgesia in mice.

  A Capasso
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  ABSTRACT: To study the effects of somatostatin (SST) and its antagonist cyclo-(7-aminoheptanoyl-Phe-D-Trp-Lys-Thr [Bzl]) (SSA) on morphine-induced analgesia. The pain assays were the hot plate and the tail flick test. SST or SSA per se administered intracerebrally at the doses of 0.1 and 1 mg/mouse did not change the pain threshold of mice both in the hot plate and in the tail flick test. However, at the higher dose (10 mg/mouse), SST and SSA decreased the pain threshold in the tail flick test only. SST and SSA administered at the dose of 0.1 mg/mouse did not change morphine-induced analgesia. By contrast, SST and SSA at the doses of 1 and 10 mg/mouse reduced morphine analgesia effects both in the hot plate as well as in the tail flick test. Our results indicate that SSA as well as SST may be useful in studying pain mechanisms.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1079-82.
• Article: Hyperpolarization caused by serotonin contributes to endothelium-dependent relaxations in the porcine coronary artery.

  S J Park, M Nakashima, T Nagao, P M Vanhoutte
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  ABSTRACT: The present study was designed to investigate the contribution of membrane hyperpolarization to endothelium-dependent relaxations induced by serotonin in the porcine coronary artery. Rings with and without endothelium of porcine coronary arteries were suspended in conventional organ chambers for the measurement of isometric force. The cell membrane potential of the vascular smooth muscle cells was measured using glass microelectrodes, in the presence of indometacin, ketanserin, and/or N omega-nitro-L-arginine. Serotonin induced a transient endothelium-, and concentration-dependent relaxation in rings contracted with prostaglandin F2 alpha in the presence of N omega-nitro-L-arginine (maximal relaxation: 19%). The N omega-nitro-L-arginine resistant relaxation was abolished by high K+ and tetrabutylammonium chloride. Serotonin also caused an endothelium-, concentration-dependent membrane hyperpolarizations with a maximal amplitude of -8.8 mV. The nitro-L-arginine resistant relaxations and hyperpolarizations were abolished by methiothepin, but not by glibenclamide. The time course of the endothelium-dependent relaxations and hyperpolarizations was similar. These results suggest a contribution of cell membrane hyperpolarization to the endothelium-dependent relaxations induced by serotonin in the porcine coronary artery.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1093-7.
• Article: Dendritic glutamate-induced bursting in prefrontal pyramidal cells: role of NMDA and non-NMDA receptors.

  X X Zhang, W X Shi
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  ABSTRACT: To investigate whether in the prefrontal cortical (PFC) pyramidal cells, focal glutamate application to the apical dendrite induces bursting and whether the effect of glutamate involves activation of both NMDA and non-NMDA receptors. Pyramidal cells in layers V and VI of the PFC were visualized in rat brain slices using infrared videomicroscopy and recorded with whole-cell electrodes. Glutamate and its agonists were focally applied to the apical dendrite and the soma using microiontophoresis. Dendritic glutamate application (0-20 nA, 10 mmol/L) induced repetitive bursts in most cells tested (12/17). In the same cells, somatic glutamate (5-20 nA, 10 mmol/L) induced only regular spiking. The bursting effect is likely to be direct since applications 5 microns away from the dendrite resulted in either a much reduced effect or no effect. Both CGP 37849 1 mumol/L and NBQX 1 mumol/L reduced the effect, suggesting an involvement of both NMDA and non-NMDA receptors. However, when non-NMDA receptors were selectively activated using AMPA (2-50 nA, 10 mmol/L), only regular spiking was observed. In contrast, selective NMDA receptor activation (NMDA 1.3-25 nA, 100 mmol/L) reliably induced bursting. In most PFC pyramidal cells tested, dendritic glutamate application induces repetitive bursting, whereas somatic glutamate application induces only regular spiking. Both NMDA and non-NMDA receptors are activated during dendritic glutamate application. However, bursting is primarily mediated by NMDA receptors.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1125-31.
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  Article: Intrathecal cannabinoid administration suppresses noxious stimulus-evoked Fos protein-like immunoreactivity in rat spinal cord: comparison with morphine.

  A G Hohmann, K Tsou, J M Walker
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  ABSTRACT: To determine whether cannabinoids suppress noxious stimulus-evoked Fos protein-like immunoreactivity (FLI) through direct actions at the spinal level. Rats were implanted with intrathecal (ith) catheters at least one week prior to evaluation in the formalin test. Effects of the cannabinoid agonist, CP55,940 (80 micrograms ith) on formalin pain and FLI in rat spinal cord were compared with that of the prototypic narcotic analgesic, morphine (20 micrograms ith). CP55,940 suppressed pain behavior and FLI induced by intraplantar formalin. The cannabinoid suppressed Fos in the neck region of the dorsal horn and in the ventral horn, but not in the nucleus proprius. The efficacy of the cannabinoid in suppressing FLI in these laminae and pain behavior was comparable to morphine administered via the same route. However, only morphine suppressed FLI in the superficial dorsal horn relative to vehicle treatment. Cannabinoids suppress nociceptive processing, in part, through actions at the spinal level. However, morphine showed greater potency and efficacy than CP55,940 in suppressing formalin-induced FLI following spinal administration.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1132-6.
• Article: 5-HT receptors mediating external carotid vasoconstriction in vagosympathectomized dogs.

  C M Villalón, D Centurión, A Sánchez-López, P De Vries, P Saxena
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  ABSTRACT: One specific example reflecting the complexity of cardiovascular responses induced by serotonin (5-hydroxytryptamine; 5-HT) and the progress achieved in the pharmacological characterization of the receptors involved can be illustrated by the effects of 5-HT on the canine external carotid artery bed. Within this framework, it has been shown that the external carotid vasoconstrictor response to 5-HT in the dog is mediated by '5-HT1-like' receptors, which being blocked by the 5-HT1B/1D receptor antagonist GR127935, resemble 5-HT1B/1D (previously called 5-HT1D beta/1D alpha) receptors. It was proposed that these receptors could belong to the 5-HT1B, rather than the 5-HT1D, subtype on the basis of their resistance to blockade by a high dose of ritanserin (a potential 5-HT1D receptor antagonist) and the presence of mRNA for 5-HT1B(5-HT1D beta) receptors, but not for 5-HT1D(5-HT1D alpha) receptors, in vascular smooth muscle. With the advent of subtype-selective antagonists it was subsequently shown that external carotid vasoconstriction to 5-HT and sumatriptan is dose-dependently antagonized by the selective 5-HT1B receptor antagonist SB224289 (2,3,6,7-tetrahydro-1'-methyl-5-[2'-methyl-4' (5-methyl-1,2,4-oxadiazol-3-yl) biphenyl-4-carbonyl] furo [2,3-f] indole-3-spiro-4'-piperidine hydrochloride), whereas the selective 5-HT1D receptor antagonist BRL15572 (1-(3-chlorophenyl)-4-[3,3-diphenyl (2-(S,R) hydroxypropanyl) piperazine] hydrochloride) was ineffective. These findings represent the first in vivo evidence showing that vascular constriction induced by 5-HT and sumatriptan is mediated primarily via 5-HT1B, but not 5-HT1D receptors. The pharmacological profile of these receptors could be similar (isolated human temporal artery and porcine carotid arteriovenous anastomoses) to other putative 5-HT1B receptors mediating vasoconstrictor responses. In view of the putative pathophysiologic role of external carotid (and extracerebral) vasodilation in migraine, the constriction of these blood vessels by sumatriptan via 5-HT1B receptors may be, at least partly, responsible for its therapeutic efficacy in migraine.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1057-67.
• Article: Modulation by muscarinic receptor antagonists on negative chronotropic effects of tetrandrine.

  N Zhong, J Q Qian
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  ABSTRACT: To investigate the influence of selective antagonist for muscarinic (M) receptor subtype on tetrandrine (Tet) reducing heart rate, inhibiting sinoatrial node (SAN) function, and its ionic mechanism. Effects of reducing heart rate of Tet were maintained in isolated right atrium and pithed rats. Modification on action potentials (AP) of SAN cells and L-type calcium current (ICa-L) by Tet were recorded by means of standard microelectrode and patch-clamp whole cell recording techniques. Tet inhibited spontaneous beating rate of isolated right atrium (EC50, 23.7 mumol.L-1) and reduced heart rates in pithed rats in a concentration-dependent manner (EC50, 18.6 mg.kg-1). Automaticity of SAN was inhibited by Tet. AP upstroke velocity (Vmax), spontaneous depolarization rates in phase 4 (SP4) were decreased and sinus cycle length (SCL) was prolonged when treated with Tet. Tet (30 mumol.L-1) caused a reduction in peak value of ICa-L from (1275 +/- 190) pA to (498 +/- 94) pA in isolated single cardiomyocyte. Atropine and AF-DX 116 (M2 subtype selective antagonist) could attenuate such effects of Tet in a competitive mode. Negative chronotropic effects of Tet are due to its inhibition of ICa-L. Modification on ICa-L is the major mechanism of M receptor modulating Tet effects.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1068-72.
• Article: Antagonistic effect of l-stepholidine on striatal ischemic injury in rat.

  F M Tang, Y M Ding, Y T Chen, Y F Sun, R Wang, G Y Zhang, G Z Jin
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  ABSTRACT: To elucidate the protection of l-stepholidine (SPD) on neuronal morphology and function against the striatal ischemic injury in rat. The forebrain ishemia to Sprague Dawley rats was induced with four-vessel occlusion. Histological examination was performed on the dorsolateral striatum with cresylviolet stain. In striatal slices of rat as an in vitro ischemic model, the activity of calcium/calmodulin-dependent protein kinase II (CCDPK) and lactate dehydrogenase (LDH) was examined by the method of 32P-incorporation and colorimetry, respectively. In the SPD-treated groups, most of the neurons in the striatum kept the normal morphological appearance after 30-min ischemia followed by 6-h or 12-h reperfusion. The number of neurons was much more in SPD groups than that in vehicle group. The sparse and abnormal neurons were observed in the vehicle group. SPD attenuated the ischemic effect on the CCDPK activity in striatal slices. In addition, SPD inhibited the leakage of LDH from neurons induced by ischemia in incubated striatal slices. SPD protected striatal neurons against ischemic injury and antagonized the inhibitory action on CCDPK activity induced by ischemia. SPD reduced the leakage of LDH from striatal neurons induced by ischemia.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1073-8.
• Article: Cannabinoid receptor antagonist SR141716A decreases operant ethanol self administration in rats exposed to ethanol-vapor chambers.

  F Rodríguez de Fonseca, A J Roberts, A Bilbao, G F Koob, M Navarro
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  ABSTRACT: To study the potential role of dependence status on CB1-mediated blockade of ethanol self-administration. We examined the effects of the cannabinoid antagonist SR141716A (0, 0.03, 0.3, and 3 mg/kg) on operant ethanol (10% v/v) self-administration in male Wistar rats that were made ethanol-dependent by chronic (14 d) exposure to ethanol vapor-chambers or exposed to air in identical vapor chambers. Dependent animals responded more for ethanol than did air control nondependent rats. The acute administration of a 3 mg/kg dose of SR141716A almost suppressed ethanol self-administration only in ethanol dependent animals. However, operant responses for food were not affected by the administration of SR141716A. These results further support that cannabinoid CB1 receptor blockade may have a potential utility for the treatment of alcoholism.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1109-14.
• Article: Increased response to prostaglandin H2 precedes changes in PGH synthase-1 expression in the SHR aorta.

  T Ge, P M Vanhoutte, C M Boulanger
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  ABSTRACT: To determine the expression of PGH synthase-1 and the sensitivity of vascular smooth muscle to PGH2 in the aorta from the SHR at an age when no endothelium-dependent contractions to acetylcholine are observed under control conditions. All experiments were performed in parallel on aortas from 20-wk-old SHR and Wistar-Kyoto normotensive rats (WKY). Rings, with or without endothelium, were suspended in conventional organ chambers for the recording of changes in isometric force. The expression of PGH synthase-1 was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Under control conditions acetylcholine did not cause contractions of rings with or without endothelium. However, in the presence of nitro-L-arginine (NLA, an inhibitor of nitric-oxide synthase), it evoked endothelium-dependent contraction in the SHR but not in the WKY aortas. The expression of PGH synthase-1 was comparable in the aortas of both strains (with and without endothelium). PGH2 caused greater contractions in rings without endothelium from the SHR than those from WKY, while U46,619 evoked a comparable response, in aortas from both strains. In the aorta of 20-wk-old SHR, endothelium-dependent contractions to acetylcholine are observed only when the production of nitric oxide is prevented. They are associated with an augmented sensitivity of the smooth muscle to PGH2, but not with an increased expression of PGH synthase-1.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1087-92.
• Article: CB1 receptor localization in rat spinal cord and roots, dorsal root ganglion, and peripheral nerve.

  M C Sañudo-Peña, N M Strangman, K Mackie, J M Walker, K Tsou
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  ABSTRACT: The localization of CB1 receptors in the spinal cord, spinal roots, dorsal root ganglion (DRG), and peripheral nerve of the rat was determined. We studied the distribution of CB1 cannabinoid receptors by immunohistochemistry using an antibody raised against the N-terminal of the receptor. The spinal cord showed numerous transverse fibers labelled for CB1 receptors throughout and concentrated in the dorsal horn. Lightly-stained cells were observed throughout the spinal cord gray matter. The DRG also showed cells and fibers labelled for CB1 receptors. Labelled fibers were observed in both dorsal and ventral roots as well as in peripheral nerves. The presence of CB1 receptors in the DRG, the dorsal root, and the dorsal horn is in accordance with the analgesic effects of cannabinoids. The presence of labelled cells and fibers in the ventral horn and ventral root provides a substrate for cannabinoid-induced muscle relaxant and antispastic effects.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1115-20.
• Article: Dopaminergic system does not play a major role in the precipitated cannabinoid withdrawal syndrome.

  M C Sañudo-Peña, M Force, K Tsou, G McLemore, L Roberts, J M Walker
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  ABSTRACT: To determine the dopaminergic system involvement in precipitated cannabinoid withdrawal syndrome. The dopamine D1 receptor antagonist SCH23390 or the dopamine D2 receptor antagonist sulpiride was administered to rats chronically treated with either delta 9-tetrahydrocannabinol (THC) or vehicle. Subjects were then injected with either SR141716A or vehicle and behavior was observed for 1 h. Administration of the cannabinoid receptor antagonist SR141716A to animals chronically treated with THC as described by Tsou et al (1995) produced a profound withdrawal syndrome. Treatment with dopamine antagonists did not attenuate cannabinoid precipitated withdrawal syndrome in THC tolerant animals while the agonists increased the syndrome. It is unlikely that the dopaminergic system plays a major role in mediating the behavioral aspects of the cannabinoid withdrawal syndrome.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1121-4.
• Article: Hypoglycemia induced by insulin increases hepatic capacity to produce glucose from gluconeogenic amino acids.

  G R Borba-Murad, M Vardanega-Peicher, H M Souza, G Lopes, M H Fonseca, R B Bazotte
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  ABSTRACT: To investigate the hepatic capacity to produce glucose during hypoglycemia induced by insulin (HII). Livers from 24-h fasted rats which received i.p. insulin (HII rats) or saline (control rats) were perfused in situ. The gluconeogenic substrates L-alanine (5 mmol/L), L-glutamine (5 mmol/L), L-lactate (2 mmol/L), and glycerol (2 mmol/L) were employed. The gluconeogenic activity was measured as the difference between rates of glucose released during and before the substrate infusion. In part of the experiments the production of urea was measured. Before the liver perfusion blood was collected for determination of glycemia and insulinemia. HII rats showed: (a) hypoglycemia and hyperinsulinemia; (b) increased hepatic capacity to produce glucose from L-alanine and L-glutamine; (c) increased hepatic ureogenesis from L-alanine and L-glutamine; and (d) increased hepatic glucose production from glycerol. However, hepatic glucose production from L-lactate was not affected by hypoglycemia. In spite of hyperinsulinemia the hepatic capacity to produce glucose from L-glutamine and L-alanine increased during HII. These results can be attributed to the higher hepatic catabolism of both amino acids, since the ability of the liver to produce glucose was not affected by hypoglycemia.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1083-6.
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  Article: SR141716A induces in rats a behavioral pattern opposite to that of CB1 receptor agonists.

  B Costa, M Colleoni
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  ABSTRACT: To examine the acute actions of the CB1 cannabinoid receptor antagonist SR141716A [N-piperidino-5-(4-chlorophenyl)- 1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide] on typical behavioral pattern of psychoactive cannabinoids in rats. At different time after injection the tail-flick response latency, the rectal temperature, the locomotor activity, and the immobility on a ring as well as the numbers of rears, self-grooming episodes (lasting 5 s), and fecal pellets were measured. Acute administration of SR141716A (3 mg/kg i.p.) induced a significant increase in horizontal locomotor activity assayed by an activity meter, in stereotypic activity (such as rearing and self-grooming) and in defecation, and a decrease in nociceptive threshold recorded as tail-flick latency. This dose had no effect on ring immobility and did not change the body temperature. These results demonstrate that this cannabinoid antagonist itself was inducing behavior opposite to that of CB1 receptor agonists.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 01/2000; 20(12):1103-8.
• Article: KN-62 provides neuroprotection against glutamate-induced excitotoxicity in neurons.

  C Gao, G Y Zhang
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  ABSTRACT: To study the effects of KN-62, an inhibitor of Ca(2+)-calmodulin dependent protein kinase II (CCDPK II), on the damage of cortical neurons and mechanisms of the loss of CCDPK II activity induced by sodium glutamate (Glu). CCDPK II activity was measured by 32P incorporation and backphosphorylations of endogenous proteins were studied by autoradiography. 1) KN-62 provided partial protection against excitotoxical damage only before Glu (100 mumol.L-1, 10 min) treatment. 2) KN-62 markedly suppressed the loss of CCDPK II activity induced by Glu from 48.0% to 90.6%. 3) Backphosphorylation of endogenous proteins (especially the 50 kDa protein) reduced to 78.2% of control after treatment with Glu, and the reduction was protected with KN-62 added before Glu. KN-62 provided the protection against excitotoxicity and the loss of CCDPK II activity as well as backphosphorylation of endogenous proteins induced by Glu. The neuroprotection provided by KN-62 was due to the inhibition of autophosphorylation of CCDPK II.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):991-4.
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  Article: Effects of ascorbic acid on human hepatoma cell proliferation and redifferentiation.

  J H Kang, Y M Shi, R L Zheng
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  ABSTRACT: To examine the effects of ascorbic acid (AA) on hepatoma. Choosing an all-trans tretinoin (Tre) as a positive control, cell growth, and cell redifferentiation tests by cell surface charges, biochemical changes, and cell growth in soft agar were measured. After being treated with AA 6 mmol.L-1, the growth curve and mitotic index of human hepatoma cells decreased remarkably, the cellular growth inhibitory rate amounted to 58.9%. The indices related with cell malignancy alleviated, such as cell surface charge obviously decreased, the electrophoresis rate dropped from 1.64 microns.s-1.V-1.cm-1 to 0.93, the average value of alpha-fetoprotein (alpha-FP) content decreased from 302 micrograms.g-1(protein) to 90, and gamma-glytamyl-transpeptidase (gamma-GT) activity from 0.81 U.g-1(protein) to 0.16. The index related with cell differentiation increased, such as the average level of tyrosine-alpha-ketoglutarate transminase activity increased from 10.3 micromol.g-1(protein) to 41.2, and the colonogenic potential decreased 94.4%. AA can inhibit human hepatoma cells proliferation, induce redifferentiation, and reverse its malignant phenotypic characteristics.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):1019-24.
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  Article: Quantitative design of drug compatibility by weighted modification method.

  Q S Zheng, R Y Sun
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  ABSTRACT: To set up a new method for designing and quantitatively analyzing drug compatibility. Drugs for compatibility were divided into 6 dose levels which were evenly distributed to 6 compound groups according to a fixed design. A new mathematical model was set up to fit the dose-effect data of 6 groups. The coefficients, obtained from the model, reflected the dose-effect relationship and the important degree of every drug in combination. According to the coefficients, the drugs in compatibility could be distinguished into principal drug, synergist, inferior, antagonist, and assistant. Because compatibility in the maximal effect group was nearly (or was) an optimal one in 6 groups, the doses in the group were taken as a base for further modification which considered interaction among drugs. The results of the modification were demonstrated by further experiment. This method was applied to design and to quantitatively analyze the compatibility of allantoin, metronidazole, and dexamethasone sodium phosphate by 2 effect indices in mice. This new method was able to effectively determine important degree of drugs in combination, and to optimize their doses for designing compatibility. This weighted modification method is a highly efficient, accurate, and practical means for designing and quantitatively analyzing drug compatibility.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):1043-51.
• Article: Specificity of inducible nitric-oxide synthase inhibitors: prospects for their clinical therapy.

  Z Q Liu, S M Wildhirt, H H Zhou
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  ABSTRACT: Nitric oxide (NO) is a ubiquitous, naturally occurring molecule found in a variety of cell types and organ systems. It is a double-edged sword, beneficial as a messenger or modulator and for immunology self-defense, but potentially toxic. The formation and signal function of nitric oxide are mainly modulated by nitric-oxide synthase (NOS). Up to the present, a number of diseases, including circulatory shock, atherosclerosis, cardiac allograft rejection, chronic inflammation, cardiac infarction, cancer and so on, have been demonstrated that their pathogenesis may be involved in the sustained production of large quantities of nitric oxide. Animal studies and human studies have shown that specific inhibitors of inducible nitric-oxide synthase may be useful in the therapy of a variety of diseases associated with induction of nitric-oxide synthase. In this review, we compare and contrast these inhibitors along with examples of their use in the studies of medicine.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):1052-6.
• Article: Effects of ligustrazine, tanshinone II A, ubiquinone, and idebenone on mouse water maze performance.

  X J Liu, W T Wu
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  ABSTRACT: To observe the effects of four drugs, ligustrazine (Lig), tanshinone II A (Tan), ubiquinone (Ubi) and idebenone (Ide), on learning and memory of mouse. Mouse water maze was used to evaluate nootropic effect. In comparison with the defective model (only scopolamine 3 mg.kg-1, Tan 20 mg.kg-1, ig) shortened the escape latency dramatically from (36 +/- 19) s to (11 +/- 5) s (P < 0.01) and reduced errors from 7 +/- 5 to 1.5 +/- 1.3 (P < 0.05). Ubi 20 mg.kg-1 ig decreased the escape latency from (37 +/- 18) s to (17 +/- 12) s and errors from 8 +/- 5 to 2.1 +/- 2.7 (P < 0.01). Ide 120 mg.kg-1 (ig) reduced the errors from 8 +/- 6 to 3.4 +/- 2.9 (P < 0.05), but had no remarkable effect on the escape latency. Lig did not exhibit marked effect on the deficit. Tan, Ubi, and Ide improved scopolamine-caused spatial performance defects in mouse.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):987-90.
• Article: Pharmacokinetics of intragastric ipriflavone solid dispersion in rats.

  Y P Li, J J Zhou, X Y Zhang, Y Y Pei
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  ABSTRACT: To evaluate pharmacokinetic behavior of ipriflavone solid dispersion in rats. The plasma concentrations of ipriflavone in rats were determined by HPLC with UV detector. Plasma concentration-time curves after ig ipriflavone solid dispersion 250 mg.kg-1 in rats were fitted with one-compartment model. Pharmacokinetic parameters were as follows: Ke = 0.21 h-1, T1/2Ke = 5.19 h, Ka = 1.71 h-1, T1/2Ka = 0.41 h, Tmax = 0.67 h, Cmax = 429 micrograms.L-1, AUC = 3916 micrograms.h.L-1; The relative bioavailability of ipriflavone solid dispersion was 323%. Ipriflavone in solid dispersion was absorbed more effectively than that in physical mixture in rats.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):1035-8.
• Article: Effects of changrolin on potassium currents in guinea pig and rabbit single heart cells.

  L L Lü
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  ABSTRACT: To elucidate whether or not changrolin (CRL) modifies the potassium currents (ITO, IK, and IKl) in myocardial cells. A tight seal whole-cell patch-clamp technique was used to record ITO, IK, and IKl in single cells isolated from guinea pig and rabbit hearts. At a clinically relevant concentration, CRL 50 mumol.L-1 inhibited the transient outward current (ITO) by 17.7% +/- 2.4% (n = 8) in rabbit atrial cells. The voltage-dependence of steady-state inactivation of ITO was not affected by CRL. This concentration of CRL did not influence the time-independent inward rectifier or the delayed rectifier K+ currents (IKl and IK, respectively) in rabbit and guinea pig ventricular cells. CRL inhibited ITO, but not IK nor IKl.
  Zhongguo yao li xue bao = Acta pharmacologica Sinica 12/1999; 20(11):1015-8.