A new positive inotropic agent, sulmazole (base or HC1, l mg/kg i.v) increased dp/dtmax and LVSP significantly in anesthetized open chest cats (Ac) and acute heart failure cats (Fc).HR was increased minimally. The dp/dtmax values were increased by 7% (base, Ac), 13% (HC1, Ac), and 45% (base, Fc) respectively. In addition, sulmazole decreased LVEDP, and increased CO and MAP in Fc, while it lowered MAP in a dose-dependent manner (Ac).The lowest doses of sulmazole induced arrhythmia were 10 mg/kg i.v (Ac), and 20 mg/kg i.v (Fc), and the arrhythmia was reversible. When the dose was increased to 30mg/ kg i.v (base), severe arrhythmia could be produced in most cats.The ratio between toxic dose and effective dose was 10-30.Ouabain, 30 ?g/kg i.v, increased dp/dtmax, LVSP and MAP, and decreased HR significantly i Ac. Ouabain, 60 ?g/kg i.v, produced severe irreversible arrhythmia and most cats died (n = 6/8). The ratio between toxic and effective dose was less than 2.

The inhibitory effects of cicletanine (Cic) and bepridil (Bep) on norepinephrine (NE)-and KCl-induced contractions were studied in isolated thoracic aorta rings of male Sprague-Dowley rats. It was found that Cic had a more potent effect on NE-induced contraction than on KCHnduced contraction. In. contrast, Bep had a more potent action on KCHnduced contraction. When the aorta rings were incubated with Cic and Bep, a potentialized inhibitory effect was observed on KCh but not NE-induced contractions. These effects were independent of the presence of endothelium. The results suggest that Cic and Bep have different action sites and properties on vascular smooth muscles.

The effects of tetrandrine and neferine on the phenylephrine-induced contractions were studied in Sprague-Dawley rat aortic rings. It was found that both tetrandrine and neferine ( 2?10-5 mol/L ) markedly inhibited phase I ( release of intracellular calcium) and phase II (entry of extracellular calcium) contractions after a 20 min incubation. After a shorter incubation period, tetrandrine and nefrine inhibited only the phase II contractions. Compared with tetrandrine, neferine exhibited slower and weaker effects

The effects of tetrandrine (Tet) on blood pressure, plasma renin activity (PRA) and the contractility of the papillary mascle and portal vein were studied in rats. After 4 d administration of Tet 30 mg/kg, 2/d, ig, blood pressure was decreased markedly in anesthetized male SD rats, but there were no effects on heart rate and PRA. A single dose of Tet 15 mg/kg iv reduced blood pressure and heart rate significantly, while did not change PRA. This single dose produced similar hypotensive effect in rats with and without pretreatment of Tet 30 mg/kg, 2/d, 4d, indicating the absence of tolerance. Tet inhibited the paced papillary muscle contractility and the spontaneous portal vein contractility, and the EC50 were 5.33?10-6mol/L and 4.25?10-5 mol/L, respectively. So the vascular selectivity of Tet is 0.12.

The purpose of this study is to investigate the effects of intravenous tetrandrine (Tet) on the outcome of myocardial ischemia and reperfusion. Tet 4mg- kg-1 iv significantly reduced arrhythmias resulting from a coronary artery ligation and reperfusion. It is suggested that Tet may be a prospective anti-arrhythmic drug in ischemic heart disease.

The effects of long-term treatments with 7 antihypertensive agents on the functions of endothelium-dependent relaxation were studied in spontaneously hypertensive rats (SHR). It was found that captopril, atenolol and dihydrochlorothiazide (DHT) could prevent the endothelium in SHR from impairing, but tetrandrine, nitrendipine, prazosin and dihydralazine could not. The improvement of the function of endothelium-dependent relaxation was not related to the blood pressure lowing.

The effects of nitrendipine (Nit) and tetrandrine (Tet) on the contents of ?-aminobutyric acid (GABA) in the hypothalamus and cortex were studied in spontaneously hypertensive rats (SHR). The results showed that short-term (1 week) and long-term (20 weeks) treatments with Nit and Tet produced a decrease in blood pressure and an increase in GABA contents in the hypothalamus but not in the cortex. These findings suggest that the action of Nil and Tet on GABA contents in the hypothalamus may be partially contributed to their antihypertensive effects.

Objective To evaluate the effect of hypothermia on the endotracheal tube cuff pressure during cardiopulmonary bypass in the pediatric patients with congenital heart disease. Methods Forty pedi-atric patients of both sexes, of American Society of Anesthesiologists physical status Ⅱ-Ⅳ, aged 1 months-14 yr, weighing 3-58 kg, scheduled for elective surgery for congenital heart disease using cardiop-ulmonary bypass, were included in this study. All the pediatric patients were intubated with a cuffed endo-tracheal tube. After anesthesia induction and endotracheal intubation, the air was injected into the cuff to make the cuff pressure reach 20 cm H2 O ( baseline) . The endotracheal tube cuff pressure was recorded when the esophageal temperature was reduced to 34, 32, 30, 28 and below 28℃ and returned to 28, 30, 32, 34 and 36 ℃. Results The cuff pressure was significantly decreased when the esophageal temperature was reduced to 30 and 28 ℃ and below 28 ℃ and returned to 28, 30, 32 and 34 ℃ as compared with the baseline ( P<0. 05) . Conclusion Hypothermia can reduce the endotracheal tube cuff pressure during car-diopulmonary bypass, and it is recommended to routinely monitor the cuff pressure in the pediatric patients with congenital heart disease.

OBJECTIVE: To construct an universal recombinate adeno-associated virus (AAV), rAAV-NT4-ADNF-9, and to detect the ability of transfection of the rAAV vector into cochlea in vitro. METHOD: pSSVHG-CMV-ADNF-9 plasmid was introduced into 293 cell by method of Ca3 (PO4)2 using three plasmids of pSSHG-CMV-NT4-ADNF-9, pFG140 and pAAV/Ad. The recombinate adeno-associated virus (rAAV) was harvested, and the titrations of the rAAV concentrated was detected by dot-blot test. Isolate and culture the cochlear hair cell of SD rats newly born in vitro. The rAAV-NT4-ADNF-9 was added to the medium while plating. Cochlear were collected 24 h after cultivation for RT-PCR to detect the transfection of rAAV-NT4-ADNF-9. RESULT: The titration of rAAV stock produced 2 x 10(16) total particles/L, which showed that rAAV-NT4-ADNF-9 was constructed successfully. The cochlear hair cell of SD rats newly born was isolated and cultured in vitro successfully. It certified that rAAV-NT4-ADNF-9 was able to transfect into cochlear and express secretory NT4-ADNF-9 peptide by RT-PCR. CONCLUSION The rAAV vector constructed in this paper, rAAV-NT4-ADNF-9, can transfer into cochlear cultured in vitro, which layed a foundation of further research for gene therapy.
Animals ; Cells, Cultured ; Cochlea ; cytology ; Dependovirus ; genetics ; Genetic Vectors ; Hair Cells, Auditory ; cytology ; Nerve Tissue Proteins ; genetics ; Rats ; Rats, Sprague-Dawley ; Transfection