Ureteral Peristaltic Pressures in Dogs with Changing Urine Flows

Responses of Renal Function to Elevated Intravesical Pressure

“…The influence of the elevated intravesical pressure on renal function when there is no back pressure and the urine flows freely is still controversial. Several investigators, most of them using animal models, have demonstrated an inverse relationship between bladder pressure and urine output (Lucas, 1908;Pflaumer, 1919;Farrel, 1931 ;Miller and Lampton, 1941 ;Lawsonand Tomlinson, 1951;Krzeski and Trzebski, 1956;Prat, 1956;Myint and Murphy, 1957;Tolls and Dille, 1957;Langley and Kimura, 1959;Boyarsky and Martinez, 1962;Shin and Hong, 1962;Lytton ef al., 1967). This phenomenon has been attributed to a neurogenic reflex activated by the elevated intravesical pressure (Boeminghaus, 1929).…”

Hydrodynamics of the pyeloureter of the pig: An experimental study of the relationship between pressure and flow in the normal, in the obstructed, and in the transsected pyeloureter

“…In the present study the clinically accepted normal range of pressures [Whitaker, 1978, 19791 was only achieved during the baseline period, while the upper limit at 2 mll min was in the equivocal range and, at higher flow rates, clearly in the obstructed area. High pressures have previously been found in the pig during high urine output [Djurhuus et al, 1977bl and also in the dog [Morales et al, 1952;Boyarsky and Martinez, 1962;Reuterskiold, 19691. In vitro investigations of the changes in tension in the ureter have shown that they are related to the magnitude and speed of stretch [Bulbring, 1955;Vereecken et al, 1973;Vereecken, 19761. Excessive sudden stretch might therefore cause higher pressures in the pelvis in steady state than a slow gradual increase.…”

“…In dogs, Boyarsky and Martinez [1964], Vaughan et a1 [1970], and Koff and Thrall [1981] found a pelvic baseline pressure of approximately 25 cm H 2 0 regardless of the degree and duration of obstruction. Similar results were obtained by Kinn and Bohman [ 19831 in rabbits and by Djurhuus et a1 [ 1976al and Mortensen et a1 [ 19831 in pigs. In the latter investigation the mean pelvic pressure was 44 cm H 2 0 after 10 weeks of total obstruction in spite of that renal function had totally ceased.…”

“…This is further stressed by findings of noncoaptive peristalsis in the chronically dilated ureter [Backlund and Reuterskiold, 1969a;Rose and Gillenwater, 19731. As underlined by the results of several experimental investigations, these compensatory mechanisms can, therefore, hardly normalize the intrapelvic pressure. In dogs, Boyarsky and Martinez [1964], Vaughan et a1 [1970], and Koff and Thrall [1981] found a pelvic baseline pressure of approximately 25 cm H 2 0 regardless of the degree and duration of obstruction. Similar results were obtained by Kinn and Bohman [ 19831 in rabbits and by Djurhuus et a1 [ 1976al and Mortensen et a1 [ 19831 in pigs. In the latter investigation the mean pelvic pressure was 44 cm H 2 0 after 10 weeks of total obstruction in spite of that renal function had totally ceased.…”

“…On the other hand, it might be of interest to correlate these results with chronic obstruction results. It is conceivable that the moderate and severe degrees of obstruction would have caused dilatation when the size of species, the degree of luminal narrowing, and the progression in dilatation in previous chronic experiments after partial ligation is considered [Boyarsky and Martinez, 1964;Koff and Thrall, 19811.…”