The Digital Water Plethysmometer is designed to provide a highly useful tool in the measurement of small volume changes. This test is typically used to follow the evolution of the inflammatory response experimentally induced in rodents and to screen potential anti-inflammatory or anti-oedema properties of pharmacological substances.

Basically, the volume transducer is formed by two Perspex tubes interconnected and filled with a conductive solution and a platinum electrode for each chamber. All the system is supported by a stand (included) that can be placed over the control unit.

The water displacement produced by the immersion of the animal paw in the measuring tube is reflected into the second tube, inducing a change in the conductance between the two platinum electrodes. The Plethysmometer Control Unit detects the conductance changes and generates an output signal to the digital display indicating the volume displacement measured (0.01 ml resolution). The current value remains in the digital display until a new trial starts. The Control Unit is automatically zeroed between successive readings, thus making intermediate adjustments unnecessary.

The system includes as standard a volume transducer with its related calibrator and a 100 ml solution. A remote foot-switch allowing rapid hands-free experiments can be used to set control the end point of the measurement. SeDaCom software supplied with the unit can be used to automatically record the results on a PC through a RS-232 port.

Citations
Raul MK et al. (2007) Anti-inflammatory, analgesic, ulcerogenic activities of some new non-acidic diclofenac and 1, 3, 4-oxadiazole derivatives in animal models. Pharmacologyonline 2: 172-186 (2007). (Mouse, rat, India)
Bani S et al (2006) Suppression of lymphocyte activity by lupeol isolated from crataeva religiosa. Phytotherapy research 20(4): 279-287. (mouse, India)
Romero-Sandoval EA et al (2006) Vitamin A active metabolite, all-trans retinoic acid, induces spinal cord sensitization. I. Effects after oral administration. Br. J. Pharmacol. 149(1):56-64. (rat, Spain)
Ratnasooriya WD et al. (2005) Anti-inflammatory Activity of the Aqueous Leaf Extract of Ixora coccinea. Int. J. Pharmacognosy, 43(2): 147-152. (rat, Sri Lanka).
Gaitan G et al. (2004) Comparison of the antinociceptive activity of two new NO-releasing derivatives of the NSAID S-ketoprofen in rats. Br J Pharmacol. 143(5):533-40. (rat, Spain).