Chronic arterial and venous catheterization of conscious, unrestrained rats.

Abstract

GEZA FEJES-T6TH, ANIK6 NARAY-FEJES-T6TH, DIETER RATGE, AND JURGEN C. FROLICH SUMMARY A method is described for implanting arterial and venous cannulas in rats that requires only minor surgery. Catheters are introduced into the abdominal aorta through the ventral tail artery and into the vena cava through a lateral tail vein. The wounds are covered with an acrylic cuff and the catheters are brought out through a stainless steel spiral connected to the cuff and then attached to top of a metabolism cage used to house the rat. This method makes possible continuous access to the catheters in undisturbed, mobile animals. Using this model we compared mean arterial pressure, heart rate, plasma renin activity, and plasma catecholamine levels in freely moving Long-Evans rats and in Brattleboro homozygous rats. (Hypertension 6: 926-930, 1984) KEY WORDS • chronic vascular catheters • blood pressure • Brattleboro rat • plasma renin activity • plasma catecholamines A LTHOUGH most of our present knowledge in animal physiology comes from experiments performed on anesthetized animals or from in vitro studies, the utility of these preparations is often curtailed when highly complex neural or hormonal regulatory mechanisms are investigated. Basal secretion rates and plasma levels of most hormones are drastically influenced by anesthesia and surgical trauma,'" 3 and even simple handling of animals may have profound effects. The effect of general anesthesia on mean arterial pressure (MAP) and cardiovascular control mechanisms is well established, 6 and even kidney function, which was generally regarded to be immune to these interventions, has recently been found to be markedly depressed during and following general anesthesia and surgical stress.7 " 9 Although methods have been developed to study larger laboratory animals under relatively unstressed conditions, such methods have not been generally adopted for the rat.We describe a simple, chronic rat preparation that makes possible intravenous infusions, continuous monitoring of MAP and heart rate (HR), and repeated blood sampling in freely moving animals. Since vasopressin has been suggested to be involved in the regulation of blood pressure, 10 we have also compared the resting MAP of the Brattleboro rat suffering from hereditary diabetes insipidus" with the blood pressure of the normal Long-Evans rat from which the Brattleboro rat has been derived. Materials and Methods A slightly conic protecting cuff with a bulging middle portion was made from a rod of plexiglass on a lathe (Figure 1). A hole was bored into the middle portion of the cuff, and perpendicular to it a longitudinal slit was made. A 3 mm diameter stainless steel spiral, which had been previously stretched to 105% of its original length to render it more flexible, was glued into the cuff with epoxy. The first few centimeters of the spiral were fortified by surrounding it with a 4 mm diameter spiral. Two 55 cm long PE-10 tubings (ClayAdams, Parsippany, New Jersey) were fed through the spiral, the proximal ends of th...

Cardiovascular depression and stabilization by central vasopressin in rats.

“…17 -19 However, in these earlier studies arterial blood pressure was measured in anesthetized rats, in conscious animals under some degree of stress, 17 -19 or was monitored for only a short period. 9 - 17 In contrast to the blood pressure difference observed in the present study, there was very little difference in heart rate between the twostrains of rats. However, lability of blood pressure and heart rate, which is expressed as the standard deviations of mean arterial pressure and heart rate averaged for the 21-hour study period, was clearly higher in DI than in LE rats.…”

Comparison of Invasive Blood Pressure Measurements from the Caudal Ventral Artery and the Femoral Artery in Male Adult SD and Wistar Rats

“…Many studies investigating thermoregulation, microvascular surgery and anatomical structure have been performed by utilizing this vessel as an entire isolated vascular bed or as a small isolated dissected segment, [4]–[11]. Scientists have established and improved the chronic CVA cannulation technique under stress-free conditions in freely moving rats for up to 12 days [12]–[15]. However, only a few studies have focused on the in vivo function of the vessel, especially the vascular tone [15]–[17].…”

“…Scientists have established and improved the chronic CVA cannulation technique under stress-free conditions in freely moving rats for up to 12 days [12]–[15]. However, only a few studies have focused on the in vivo function of the vessel, especially the vascular tone [15]–[17]. These studies implied that the CVA might be an alternative site to the FA, not only for repeatedly performing drug administration or blood sampling but also for continuous invasive arterial blood pressure monitoring.…”

Vascular responses to leukotriene B4, C4 and D4 following FPL 55712, indomethacin, saralasin, phentolamine and verapamil in the conscious rat

“…The experiments were carried out on 9 conscious, female Sprague-Dawley rats weighing 217-255 g. The animals were kept in individual metabolic cages and were prepared according to the methods of Fejes-Toth et al, (1984) After an equilibration period of3 h, various doses of different leukotrienes were injected intravenously. Doses ranged from 3.2 x 10-9 to 5.1 x 10-8molkg-' and leukotrienes were injected in a volume of 6.25 L1I 100 g-' body wt.…”