Cardiovascular changes induced by atracurium during halothane anaethesia in the dogs

This study was carried out on 20 dogs of both sexes divided into two equal groups. Anesthesia was induced with thiopentone sodium [10 mg/kg body weight]. Tracheal intubation was performed, anesthesia was maintained with 0.5-1% halothane in oxygen. Sodium chloride solution [0.9%] was injected i.v. in one group [halothane group] as a control solution. In the second group [atracurium group], an i.v. single bolus dose of atracurium dibesylate [0.5 mg/kg body weight] was injected after halothane. The experiments were conducted up to 30 minutes after atracurium or 0.9% sodium chloride solution injection. Cardiovascular stability was evaluated in the two groups [heart rate [HR], mean arterial blood pressure [MABP] and electrocardiogram [ECG]]. Adenosine triphosphatase [ATPase] assay was done in the diaphragmatic muscle following the hemodynamic measurements in each experiment. Comparing the changes of the cardiovascular parameters before and after halothane administration showed a significant decrease in HR, a significant prolongation of QRS complex of the ECG. The R wave amplitude was not significantly increased, while the T wave of the ECG was inverted. Following the intravenous injection of atracurium, halothane-induced changes in the HR and MABP were minimized towards the prehalothane values. Still the QRS complex of the ECG tracing was prolonged. The T wave became less inverted then flat and finally upright. The ATPase activity in the diaphragmatic muscle was significantly reduced in the atracurium group. Thus, atracurium in an effective neuromuscular blocking dose [0.5 mg/kg body weight] causes no significant changes in the HR, MABP, or ECG, but it may improve some of the halothane induced alterations in these parameters. So, atracurium may be considered as a suitable neuromuscular blocking agent to be used during halothane anesthesia

Effect of the converting enzyme inhibitor [Captopril] and its interaction with the calcium antagonist [Verapamil] on lipid metabolism

The effect of a converting enzyme inhibitor [captopril] and its interaction with a calcium antagonist [verapamil] on lipid metabolism was studied. A daily dose of captopril [1 mg/200 g body weight] for 3 weeks was given to 8 rats, another group of 8 rats was given the same daily dose of captopril together with a daily dose of verapamil [125 mug/200 g body weight] for 3 weeks. At the end of the 3 weeks investigation of the differences in lipid patterns was done. Captopril alone caused significant increase in total cholesterol and triglycerides, but in the group treated with captopril and verapamil a less significant increase was revealed in total cholesterol. There were also significant changes in the different concentrations of lipoprotein fractions in the two groups. The verapamil was found to modulate the effect of captopril

role of autonomic nervous system in exercise bradycardia in rats

It has been a commonly held belief that the relative bradycardia found in athletes and in chronically exercised animals is due to an excessive vagal tone, although the experimental evidence for this is both indirect and unconvincing. Daily swimming of 1.5 hours up to a total of 45 hours produced bradycardia. The contribution of sympathetic and parasympathetic activity to the resting heart rate of trained and control rats was investigated by means of differential blockade of the autonomic nervous system by atropine sulphate and propranolol hydrochloride. This procedure permits the calculation of the intrinsic heart rate and the contribution of the autonomic tone to the control of heart rate. The calculated sympathetic tone [as% of intrinsic heart rate] in the trained rats was 87% that of the control. Reduction in the parasympathetic tone in the trained rats was only 5% that of control. It was concluded, from this study, that training bradycardia resulted from greater reduction in sympathetic than parasympathetic tone, although the activity of both sympathetic and parasympathetic was reduced in the trained rats

flunitrazepam [rohypnol] for minor anal surgery

Fifty patients subjected to minor anal surgery were anaesthetised by flunitrazepam and thiopentone and premidecated by atropine sulphate and Pethidine HCL. Pulse, blood pressure, heart, chest, and respiratory rate were assessed. Blood samples for pH and blood gas estimations were taken for 10 patients and meassured after the premedication, after flunitrazepam, thiopentone, and at the end of operation. Our results showed a significant rise in pulse rate after premedication, and insignificant changes after flunitrazepam and thiopentone. The respiratory rate decreased after premedication but showed a statistically evident change after flunitrazepam and thiopentovic pH and blood gas analysis did not reveal any significant changes during the whole procedure. Our results showed a potentiation of the residual effect of flunitrazepam, and a synergetic action of pethidine and thiopentone. Therefore, we could conclude that flunitrazepam in combination with thiopentone can produce a form of balanced anaesthesia suitable for surgical procedures of short duration

Comparative study of serum lipid pattern in alloxan and streptozotocin chemically induced diabetes in rats

Comparative study of two types of chemically-induced diabetes was performed. Twenty four male rats were divided into three equal groups : Control, alloxan, and streptozotocin [STZ] treated groups. Investigation of the differences in lipid patterns after I.V. injection of either alloxan monohydrate or STZ was done. Results obtained revealed a harmful effect of both drugs in male rats. However, it was more severe in the STZ group. Both of the two compounds produced hyperglycemia which showed no significant differences between the two groups [Alloxan and STZ]. There was significant increase in the serum cholesterol level after STZ. Significant increase in serum triglyceride levels after both drugs. Cholesterol was mainly incorporated in the VLDL in the STZ group and in the LDL in alloxan group. A linear positive correlation between serum F.F.A. and blood glucose levels was found in both types of chemically-induced diabetes which was significant in STZ group but insignificant in the alloxan group. In case of insulin-dependent diabetics, and patients under the anti-tumour drug streptozotocin attention should be directed and the above results should be considered as regards the possible harmful effects on the lipid pattern, and hyperglycemia

Comparison of some cardiovascular effects of sodium nitroprusside and nitroglycerin

The coronary haemodynamic effects of sodium nitroprusside and nitroglycerin infusions were studied in ten isolated-rabbit heart preparations. The effects of both drugs on the mean arterial blood pressure [M.A.B.P.] and heart rate were also demonstrated in fifteen intact anaesthetised dogs. Sodium nitroprusside produced a significant increase in coronary flow, a decrease in amplitude of myocardial contraction and a minimal decrease in heart rate in isolated rabbit heart, a significant abrupt decrease in M A.B.P. in intact anaesthetised dog. Nitroglycerin produced a significant increase in coronary flow, amplitude myocardial contraction and minimal increase in heart rate in isolated rabbit heart. A significant decrease in the M.A.B.P. in the intact anaesthetised dog was also established. The decrease in M.A.B.P, was rapid and of short duration after sodium nitroprusside but gradual and of longer duration after nitrolycerin. When infusions were discontinued the blood pressure returned towards pretreatment levels rapidly after sodium nitroprusside but it returned gradually after nitroglycerin