Effects of cholinergic receptor antagonists, adrenergic drugs and pethidine on the function of sphincter of Oddi isolated from rabbits / 中华消化杂志

Objective To investigate the contractive effect of atropine, noradrenaline,adrenaline and pethidine on sphincter of Oddi (SO) isolated from rabbits. Methods The rings of SO isolated from 60 rabbits were treated with Krebs solution and then were exposed to gradient atropine,anisodamin, noradrenalin, adrenaline or pethidine with 10 each. The rest 10 rings of SO treated with Krebs solution only were served as controls. The amplitude and frequency of contraction of SO were recorded. Results Compared with control group, all of the 5 medicines were able to significantly decrease the contractive amplitude, but not frequency, of SO at the concentrations ranged from 10-6 mol/L to 10-2 mol/L (P＜0.05). The inhibition order was as follows: noradrenaline ＞ adrenaline ＞atropine ＞ anisodamin ≈ pethidine. Conclusions Beside atropine and anisodamin, noradrenaline,adrenaline and pethidine also showed the direct relaxation of SO by decreasing contractive amplitude of SO. Adrenaline or noradrenaline displayed stronger effect in decreasing contractive amplitude of SO when compared with atropine or anisodamin.

Influence of lyophilized Radix Astragali powder injection on hemodynamics of dogs with myocardial ischemia / 生物医学工程学杂志

In order to observe the influence of lyophilized Radix Astragali powder injection on hemodynamics and myocardial consumption of oxygen of dogs with myocardial ischemia, we establised the myocardial ischemia model by ligating the anterior descending branch of left coronary artery of 5 mongrel dogs. Then the drugs were administered intravenously, and the hemodynamic parameters and myocardial consumption of oxygen of the dogs were measured. All the Radix Astragali groups and Radix Salviae Miltiorrhizae Group (RSMG) showed significantly decreased heart rate (HR), diastolic blood pressure (DBP), mean arterial pressure (MAP) of dogs with myocardial ischemia in 5-30 min after drug administration (P < 0.05-0.01). All the Radix Astragali groups and the RSMG showed significantly lowered left ventricular end-diastolic pressure (LVEDP) of the dogs in 10 min-4 h after drug administration (P < 0.05-0.01). All the Radix Astragali groups displayed significantly increased maximum contraction velocity (+dp/dt(max)) of the dogs in 10 min after drug administration (P < 0.05-0.01). All the Radix Astragali groups and the RSMG displayed significantly increased cardiac output (CO) in 10 min-4 h after drug administration, in which the High Dose Group (HDG) of Radix Astragali displayed the highest statistical significance (P < 0.01). All the Radix Astragali groups and the RSMG exhibited significantly decreased peripheral resistance (TPR) and increased coronary blood flow (CBF) in 10 min-4 h after drug administration (P < 0.05-0.01). HDG showed significantly decreased myocardial work (MW) in 5 min-30 min after drug administration (P < 0.05-0.01). HDG and MDG exhibited significantly decreased oxygen uptake rate of the myocardium (MVo2) in 30 min-3 h after drug administration(P < 0.05-0.01). In summary, the lyophilized Radix Astragali powder injection can significantly benefit all the indexes and strengthen the heart function of the dogs with myocardial ischemia.

The changes of hemodynamic parameters, pathology and c-kit mRNA expression in myocardium after acute myocardial infarction in rats / 生物医学工程学杂志

This study was aimed to investigate the changes of hemodynamic parameters, pathology and c kit mRNA expression in myocardium after acute myocardial infarctionin (AMI) in rats, and to elucidate the relationship between these three kinds of changes. Sixty six adult male SD rats were randomly divided into normal group, Sham groups and ligation groups. The rat model of AMI was set up by ligating the left anterior descending artery. Hemodynamic parameters, pathological changes and c kit mRNA expression in myocardiam were examined. The results revealed that there were no statistically significant differences in hemodynamic parameters between normal group and Sham groups. Compared with the normal group, all ligation groups exhibited significantly decreased left ventricular systolic pressure (LVSP) and +/-dp/dtmax (P<0.01), and increased left ventricular end diastolic pressure (LVEDP, P<0.01). In the other ligation groups, compared with 6th hour group after ligation, there appeared striking increase of LVSP, LVEDP and +/-dp/dtmax (P<0.05). HE staining in myocardiam showed that there are necrosis and derangement at 24th hour group after ligation ,and a great number of inflammatory cells infiltration around the infarct zone at 3rd day group after ligation, and granulation tissue infiltrated into the infarct zone at 14th day group after ligation. In all five time points groups after ligation, the levels of c-kit mRNA expression were 0.99 fold, 1.06 fold, 1.46 fold, 1.91 fold and 2.67 fold, respectively, compared with Sham groups. The results suggest that cardiac stem cells in myocardium might contribute to the role of regenerating myocardium via self proliferation after acute myocardial infarction, but further investigation is still needed.

A sharp rise in portal vein pressure, not arterial constriction, initiates bile salt-induced pancreatic microcirculatory disturbance / 生物医学工程学杂志

It was reported that pancreatic arteries constricted during the early phase of bile salt-induced acute pancreatitis (AP), leading to pancreatic microcirculatory disturbance. We conducted this experiment to verify whether the above-mentioned finding was true. AP was induced with intraductal injection of taurodeoxyholate. Small pancreatic artery pressure in dogs was recorded. Functional capillaries were counted and calibrated by multiplying wet weight of pancreas. Pancreatic perfusion was measured with Laser Doppler flowmeter. Pancreatic arterioles of rats dilated during the initial 20 min of AP, and pancreatic arterial pressure declined during the early phase of AP in dogs (from 104.5 +/- 4.8 mmHg to 54.6 +/- 5.6 mmHg). The hematocrit of blood from inferior vena cava was significantly lower than that of portal vein at 5 min after pancreatitis induction. The "true" pancreatic functional capillary density increased. The early pancreatic microcirculatory disturbance coincided with a marked increase of portal vein pressure (PVP) as high as 9.18 +/- 0.78 mmHg. Reduction of PVP to baseline level was followed by a marked increase of pancreatic perfusion (by 1.4-fold). Arterial dilatation, but not constriction, occurred during the early phase of bile salt-induced AP. The pancreatic microcirculatory disturbance was due to a marked rise in PVP that greatly reduced the pressure difference in the pancreatic blood vessels and increased plasma extravasation which led. to local hemoconcentration.