A novel procedure for daily measurements of hemodynamical, hematological, and biochemical parameters in conscious unrestrained rats

Accurate and chronic measurements of various parameters in conscious animal s are fundamental for depicting pathological chronic conditions and their e tiology in many experimental models, but they are often difficult to achiev e. The aim of the present work was to develop and describe step-by-step a r eproducible surgical procedure and daily manipulations for continuous, chro nic use of conscious rats as models towards a better understanding of vario us cardiovascular and renal diseases and the testing of novel pharmacologic al drugs. The complete apparatus involved the use of a series of specialize d devices (harness, rotating swivel, revolving arm) supporting a flexible, permanently implanted vascular catheter into the left femoral artery up to the abdominal aorta connected to a miniaturized individual peristaltic pump for delivering fluid at a constant rate. Such a set-up also enabled easy, quick, and reproducible daily blood sampling for the evaluation of more tha n 20 parameters, including the monitoring of heart rate (HR) and blood pres sure in freely moving conscious rats. The overall success and survival rate reached 98% over 14 days and could be extended further This model represen ts a much needed and valuable advance in surgical research techniques to ev aluate the hemodynamic, hematological, biochemical, pharmacokinetic, and to xicological profile of any new drugs over time in conscious animal models s uch as rats. What makes this procedure satisfactory is the long-term reliab le arterial access and reproducibility of the methodological approach for a ccurate and continuous measurements, minimizing the stress or invasiveness associated with the use of currently employed systems. (C) 2001 Elsevier Sc ience Inc. All rights reserved.