Improved method for the catheterization of the right ventricle in a rat model of pulmonary artery hypertension.

Ventricle catheterization in the rat is widely practiced in cardiopulmonary research. The catheters deployed are either fluid filled or solid tip pressure or pressure-volume catheters. The access to the right ventricle is through the right jugular vein, most commonly without direct visualization such as fluoroscopy.

Evaluation of temperature rise and bonding strength in cements used for permanent head attachments in rats and mice.

In animal models, devices such as indwelling catheters and intracranial cannulae are often fixed on the skull to allow sampling or injection in the freely moving animal. The most commonly used method to fixate these devices is by embedding them in a 'helmet' of cement which is fixed to the skull with screws. Methylmethacrylate cement is commonly used for this purpose.

Factors stimulating or obstructing the implementation of the 3Rs in the regulatory process.

Approximately 30% of animal use within the European Union (EU) is done to meet regulatory requirements. The tests are often repetitive in nature and may cause severe suffering, due to the procedures used and to rigidly predefined end points. In addition, product evaluation procedures often take long and are very expensive.

Intraperitoneal versus subcutaneous telemetry devices in young Mongolian gerbils (Meriones unguiculatus).

Radiotelemetry has become a very popular biotelemetric tool for measuring physiological parameters such as heart rate, blood pressure, body temperature and muscle activity, as well as general behavioural activity in undisturbed, freely moving animals. In most studies using this technique, adult subjects are used. However, sometimes an ontogenetic approach is required to clarify whether changes in one parameter are preceeded or followed by changes in another parameter.

A guinea pig model of acute and chronic asthma using permanently instrumented and unrestrained animals.

To investigate mechanisms underlying allergen-induced asthmatic reactions, airway hyperresponsiveness and remodeling, we have developed a guinea pig model of acute and chronic asthma using unanesthetized, unrestrained animals. To measure airway function, ovalbumin (IgE)-sensitized animals are permanently instrumented with a balloon-catheter, which is implanted inside the pleural cavity and exposed at the neck of the animal. Via an external cannula, the balloon-catheter is connected to a pressure transducer, an amplifier, an A/D converter and a computer system, enabling on-line measurement of pleural pressure (P(pl))-closely correlating with airway resistance-for prolonged periods of time.

Measuring blood pressure in small laboratory animals.

The most common techniques currently employed for monitoring blood pressure (BP) in conscious rats and mice are the tail cuff and the exteriorized catheter that feeds a pressure transducer located outside the cage. There are, however, considerable drawbacks associated with these methods, which in many respects make each of these techniques undesirable as an accurate means of obtaining pressure measurements. Recent studies have shown that measurements of physiological variables, such as electrocardiogram (ECG), heart rate (HR), and body temperature (BT), from freely moving rats and mice by using implantable radiotelemetry were more efficient, reliable and less labour intensive when compared to measurement techniques described in the literature so far.

Effect of conditioning on the increase of heart rate and body temperature provoked by handling in the mouse.

To assess the effect of procedures on animal welfare, various physiological parameters, such as body weight, hormone levels in plasma and/or urine, heart rate (HR), blood pressure and body temperature (BT), can be used. When measuring physiological parameters with techniques involving restraint of the animals, the results must be interpreted with caution, since restraint itself may have an effect on those parameters. Radio-telemetry, using an implantable transmitter, provides a way to obtain more accurate and reliable physiological measurements from freely moving animals in their own environment.