A new method for recording vascular tone with an intravascular cuff and its application to the canine inferior vena cava in vivo.

Abstract

An intravascular cuff was devised with a short plastic cylinder and a latex membrane wrapping it, in order to examine the responsiveness of the canine inferior vena cava in vivo. The cuff was inflated by injecting saline through a catheter to make the membrane contact the vascular wall closely, and the change in the cuff pressure was recorded. An in vitro experiment with an isolated segment of the vein proved that the cuff detected quantitatively the active response of the vascular smooth muscle to norepinephrine (NE). The sensitivity to NE under this experimental condition was equal to that obtained previously with the isolated strip preparation. In the in vivo experiments, the cuff inserted into the segment between the liver and the renal veins of the inferior vena cava exhibited spontaneous rhythmic changes in pressure. In response to NE injected intravenously, dose-dependent increases in cuff pressure were observed. The responses recorded with the intravascular cuff were considered to be predominantly the active tension of the vascular smooth muscle, since influences of intestinal motion and changes in venous pressure on the cuff pressure were ruled out. The cuff picked up the response of the supradiaphragmatic segment of the inferior vena cava as well. The method seems to be useful for measuring the tone of larger veins.In previous studies (TSURU et al., 1976;SHIGEI et al., 1978 ;ICHIKAWA et al., 1979), we reported that isolated strips of the canine inferior vena cava exhibited marked differences in response to several vasoactive agents and transmural electrical stimulation among three embryologically distinct segments : the supradiaphragmatic (segment A), the infrarenal (segment D) and the segment between the diaphragm and the renal veins (segment B-C). These segments also showed differences in their histological features.In particular, the segment B-C is different from the other segments in many respects, for it is rich in longitudinal smooth muscle and adrenergic innervation.

Extrinsic innervation of the canine abdominal vena cava and the origin of cholinergic vasoconstrictor nerves

“…In the present study, an intravascular cuff was utilized for recording the vascular tone. The method was newly developed by Uematsu et al (1981) to record the active tension development of vascular wall in vivo in an isometric manner and at a resting tension of optimal range. It proved to be useful, and reproducible responses of the i.v.c.…”

“…An intravascular cuff, which was composed of a short plastic cylinder and latex membrane wrapping it, was prepared as described previously (Uematsu et al 1981). Cuffs of four different sizes (o.d.…”

“…The cuff was inflated by injection of saline, cuff pressure being monitored to be adjusted to 80-100 cm H20. Resting cuff pressure of this range distended the vein wall to its optimal level for active tension development (Uematsu et al 1981). Cuff and venous pressures were measured by pressure transducers (Nihon Kohden LPU-0-1).…”

“…To record the tension development ofi.v.c. in vivo we have devised an intravascular cuff by which only the active tension of the vein can be determined, isometrically and quantitatively, while preserving the blood flow through the hollow of the cuff (Uematsu, Ban, Ishikawa, Tsuru & Shigei, 1981).…”

Segmental Distribution of Vasa Vasorum to the Canine Abdominal Vena Cava: A Possible Correlation with its Embryogenesis

“…5,6 In fact, according to their responsiveness to vasoactive agents and neural stimuli, and histological features, it can be divided roughly into three segments, i.e., the thoracic inferior vena cava and the two segments of the abdominal inferior vena cava (A VC).1.2,:3 Recently we have devised a method by which the change in tension of dog vein wall can be measured isometrically in vivo. 7 Using this method, we have shown that the canine AVC is controlled dominantly by the right greater splanchnic nerve rather than the left once. 8 Moreover, this right-side dominancy in nervous control is more evident in the infrarenal segment of AVC than in the segment between the liver and the renal veins.…”