EFFECT OF DISTE SIO OF URINARY BLADDER 0 BLOOD PRESSUREAND RESPIRATIO

N. R. PRABHAKAR, S. D. NISIDTH A D J. P. SAXE A

Department of Physiology, Medical College, Baroda

Summary: Effect of distension of urinary bladder on blood pressure and respiration has beenstudied in 45 dogs. There is rise of blood pressure and inconsistent change in respiration aftergraded distension. Abrupt distension and distension of exteriorised bladder showed more pro-nounced results. The effect is still enhanced when both vagi are cut. The rise of blood pressureon distension of bladder is seen even after ganglion blockade and reserpinisation.

Key words: Abrupt distensionganglion blockade

graded distensionreserpinisa tion

bilateral vagotomy

The effect of abrupt and graded distension of urinary bladder on blood pressure and respira-tion in anaesthetised dogs, with intact vagus, after bilateral vagotomy, chemical sympathectomyand after administration of ganglion blocking agents is reported in the present work. These effectshave been observed in situ as well as in the exteriorised preparation.

MATERIALS AND METHODS

Forty five healthy mongrel dogs of either sex weighing between 3.5 and 16 kg were anaestheti-sed with i.v. chloralose at 80 mgmjkg. The carotid blood pressure was recorded on a movingkymograph with mercury manometer. The respiration was recorded by Marey's tambour connec-ted to a tracheal cannula.

The bladder was exposed through a mid-line incision in the abdomen above the pubic symphy-sis. An incision was made in the urinary bladder, and a rubber tube with the balloon attached toits end was introduced into the bladder. The other end of this tube was connected to sphyg-momanometer. The urinary bladder was left in situ and the incision was closed. In 3 dogs thebladder was exteriorised out of the pelvis. The balloon inside the bladder was distended with vary-ing pressures and changes in blood pressure and respiration were observed. Graded distension ofbladder to pressure of 20,40, 60, 80, 100, 120 and 140 mm. Hg and abrupt distension to 80, 100,120, 140 and 160 mm Hg was done in 27 dogs. In 7 dogs, prolonged distension at a meanintravesical pressure of 128.5 mm Hg was done for 15 min.

Bilateral cervical vagotomy was done in 12 dogs. The blood pressure of the animal wasallowed to come down to normal after vagotomy, before performing the actual experiments. In

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Volume J7Number 4

8 dogs, in addition to bilateralof pentolenium tartarate (Anckade was tested by stimulatictid arteries, showing no chamdogs by reserpinisation with.and 48 hr respectively, befor

The table shows the

Graded distension ofpressure varying from 3.2 tossure was between 100 to 1dder showed a more signifiAfter bilateral vagotomy blcompared with the controlssignificant. The rise of blo'tion in the dogs.

rFig. 1: Showi

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Abrupt distension 0

pressure than when distenficant. Adaptation of revalue of 128.5 mm Hg Ii

min followed by a gradJthough the bladder disten

Respiratory changconsistent findings.

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BLOOD PRESSURE

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nd respiration has beenange in respiration afterdder showed more pro-he rise of blood pressureisation.

I vagotomy

bloodpressure and respira-• chemical sympathectomyresentwork. These effects

and 16kg were anaestheti-as recorded on a movingMarey's tambour connec,

abovethe pubic symphy-ith the balloon attached toas connected to sphyg-as closed. In 3 dogs thewasdistended with vary-

ed. Graded distension ofpt distension to 80 100. ,

d distension at a mean

essureof the animal wasactual experiments. In

Volume17Number4

Blood Pressure During Distension of Bladder 371

8dogs,in addition to bilateral vagotomy, ganglion blockade was achieved by the i.v. administrationof pentolenium tartarate (Ansolysin, May & Baker) at the dose range of 2-3 mgjkg, The blo-ckadewas tested by stimulation of peripheral end of cut vagus and also by blocking common caro-tidarteries, showing no change in the blood pressure. Chemical sympathectomy was done in 4dogsby reserpinisation with two intramuscular injections of serpasil (Ciba), 0.5 mgjkg at 12 hrand 48 hr respectively, before the commencement of, the experiments.

RESULTS

The table shows the following results-

Graded distension of in situ urinary bladder to 20 to 140/mm Hg has shown a rise of bloodpressurevarying from 3.2 to 8.3 mm Hg. The rise was more pronounced when the distending pre-ssurewas between 100 to 140 mm Hg (Fig. 1). Graded distension of exteriorised urinary bla-dder showed a more significant rise of blood pressure which ranged between 7.6 and 11 mm Hg.After bilateral vagotomy blood pressure rise on graded distension occured more frequently whencompared with the controls before vagotomy. The rise was also more marked and statisticallysignificant. The rise of blood pressure was observed even after ganglion blockade or reserpinisa-tion in the dogs.

--------Fig. I: Showing the effect of graded distension of urinary bladder on blood

pressure (upper tracing); dotted line indicates the pretest level.Lower tracing - Time 1 div. = 1 sec.

Abrupt distension of bladder to 80mm Hg or more, in general, showed greater rise of bloodpressure than when distended in a graded fashion (Fig. 2). The results were statistically signi-ficant. Adaptation of receptors was observed during abrupt distension of bladder to a meanvalue of 128.5 mm Hg maintained for 15 minutes. The blood pressure reached its peak in 1-2min followed by a gradual fall in 7-8 mm and got stabilised below the pretest level eventhough the bladder distension continued (Fig. 3).

Respiratory changes observed on raising the urinary bladder pressure did not show anyconsistent findings.

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Intravesical pressure (mm of Hg).

IGraded distention 8'EAbrupt distention ."I~.t20 40 60 80 100 120 140 80 100 120 140 160 ".!::.J

•Normal

No. of Expts. 27 27 27 27 27 23 8 2 5 9 6 4Rise of B.P. (no.) 10 12 12 14 14 14 6 2 5 7 6 3Mean rise 3.2 4.5 4.7 4.9 7.0 7.4 8.3 7.0 6.8 13.1 13.0 25.3S.D. ± 2.15 4.19 3.23 3.39 5.54 6.13 6.25 1.41 5.76 7.10 9.18 14.06 I Fig. 2: Showing effect of abrupt

point where intravesical pJ

- Lower tracing = Time 1Exteriorised

No'. of Expts. 3 3 3 '3 3 - - 1 1 - 1Rise of B.P. (no.) 2 3 3 3 3 - - 1 - - 1Mean rise 8.6 9.0 7.6 9.6 11.0 - - 7.0 - - 5.0 - J ~.S.D.± 2.24 3.0 5.2 3.16 3.60

1

P Value <0.001 <0.001 <0.001 <0.001 <0.001 - - - - - <0.01 - I f[

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No. of Expts. 14 14 14 14 12 11 6 - 3 3 1 4Rise of B.P. (no.) 8 9 10 10 7 5 2 - 2 2 1 4Mean rise 4.25 3.3 3.8 5.6 9.0 13.0 8.0 - 16.0 16.0 6.0 17.5

S.D.± 2.34 1.14 1.48 4.0 6.08 9.65 - - 8.48 - - ]2.69p Value <0.001 <0.001 <.001 <0.01 >0.1 <0.001 >0.1 - <0.01 <0.01 <0.01 <0.01

Fig. 3: Showing effect of abrujned for ]5 min (up

t.to 78.5 mm Hg mean

Reserpinised"",i'Al 8 0 -:LB 3..4

No. of Expts. 4 1..

4 4 4 4 2 - ] 2 2 - "ne".,..

Rise of B.P. (no.) 2 1 3 2 3 1 - - 2 2 1 - " ~o'"1 (lK

Mean rise 2.0 4.0 3.3 5.0 3.3 2.0 - - 5.0 ]4.0 22.0 - . .:»:S.D .• 2.83 l.J4 1.4] 1.14 l.4l 2.82 - - ,- - - -p Value so.r >0.1 <0.01 >0.1 >0.10 >0.10 <0.01 '" '.<0.001 <0.001 - - - t

",Ganglion Blockade , E

~ /4. 1 ,.., , AL 80

~"No. of Expts. !\ 8 8 8 5 4 2 1 2 2 - -

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Rise of B.P. (no.) 4 3 4 2 2 4 2 1 2 1 - - . ,

h~Mean rise 3.0 3.0 4.5 8.0 4.0 6.0 5.0 4.0 7.0 8.0 - - .S.D. ± 2.0 1.0 'U2 ')..83 2.83 3.65 1.41 - 4.24 - - - z I,... \I..••C'Of(~ .•••

P Value . >0.1 <0.001 >0.1 <0.001 <0.001 <0.01 <0.01 >0.1 >0.1 <0.01 - - cc ~') so 8 ;): I---. ",

372' Prabhakar et al. October 1973Ind. J. Physiol. Pharmac.

TABLE: Showing effect of distension of urinary bladder on blood pressure.

Volume 17Number 4

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Blood Pressure During Distension of Bladder 373October 1973

lnd. J. Physiol. Pharmac.

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100 120 140 160

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2 2 12 2 15.0 14.0 22.0IAl 2.820.10 >0.10 <0.01

2 22 17.0 8.04.240.1 <0.01J-------------------------

Fig. 2: Showing effect of abrupt distension of bladder on blood pressure (upper tracing), t indicates the

point where intravesical pressure was raised, .j, indicates release of intravesical pressure.

Lower tracing = Time 1 div. = 1 sec.14,

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Fig. 3: Showing effect of abrupt distension of bladder to 128.5 mm Hg mean intravesical pressure maintai-ned for 15 min (upper tracing). Lower tracing shows the effect of abrupt distension of bladderto 78.5 mm Hg mean intravesical pressure maintained for 9 mm after ganglion blockade.

Fig. 4: Showing effect of gradeddistension of urinary bladder onblood pressure in normal, texeriorised,vagotomised, after ganglion blockadeand reserpinised animals.

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374 Prabhakar et al. October 1973Ind. 1. Physiol. Pharmac,

DISC lSSIO

As early as 1899, Sherrington (8) demonstrated that the distension of hollow viscera like urateror bile duct resulted in reflex vascular responses. Reflex responses of nictitating membraneand the blood pressure to distension of bladder and rectum have been reported (9). Paraplegics(C - Ts) have been known to exhibit blood pres ure increase on distension of urinary bladder(3). Mukherjee (6) reported vasomotor response on disten ion of bladder in the cat. This res-ponse was more marked after bilateral vagotomy and carotid sinus denervation and was abolishedafter splanchnicotomy.

Present observations show a rise of blood pressure after a lag period of 30 to 60 seconds ondi ten ion of urinary bladder. The lag period varied with the degree of distension. At low di -tension pressure the lag period was more but a the distension pressure wa raised above100 mm, Hg the lag period shortened.

The rise of blood pressure has been observed in res ponse to graded distension and abruptdistension of bladder ill situ and when it wa exteriorised. Comparing the results in these situations,it is evident that the rise of blood pressure is more marked on graded distension in exteriorisedbladder. Abrupt distension shows still more rise of blood pre sure ranging between 7 to 25 mill

Hg. This rise of blood pressure in response to distension has been attributed to stimulation of pro-prioceptive end organs, situated in the bladder wall. Two factors may work in stimulation ofthese end organs; either the absolute rise of intravesical pressure or increase in the volume ofbladder. In the in situ bladder inspite of increase of intravesical pressure the volume of thebladder is limited by the pelvis. In exteriorised bladder volume of the bladder increase with therise of intravesical pressure. Since the results indicate a more marked rise in exteriorised bladder,it i probable that increase in the volume of the bladder play a more important part in stimu-lation of the tension mechanoreceptors rather than absolute rise of intravesical pressure. Thealteration of the intravesical pressure is minimum over a wide range of intravesical volume.Similar results are reported by other workers (5).

Mechanoreceptors of the bladder have been studied by Adamovich (1) and later by Koshino(5). They have reported that these tension mechanoreceptors are sen itive to abrupt tretch,adapting within 5-60 seconds. Electrical activity in the hypothalamus due to stimulation of thesetension mechanoreceptors with the rise of intravesical tension has also been reported (2). Thereceptors are reported to be interpo ed in series with detrusor muscle and are more abundant in thebladder neck region (4).

Abrupt distension of bladder to a mean value of 128.5 mm Hg in the present work showed aquick rise of blood pre sure. When this distension was maintained to that level for 15 min,the blood pressure showed a gradual fall in 7-8 min and later got stabilised below tbe pretestlevel even though the distension wa continued. The tension mechanoreceptors showed the phe-nomenon of adaptation. Similar reports of adaptation of these receptors have been published byearlier workers (1,5).

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Volume l~umber 4

The effect of graded distertion are showin in Fig. 4. Th!ficant following vagotomy.resulting in considerable ri e 0

with results of other workers

The rise of blood pre surechnic vasoconstriction and aoresponse was abolished afterpresent study to decrease the t(cing the blood pressure. Grareserpinisation howed a ri e csubstance released in the cireblood before and after distensof pressor response.

The author~ wish to thanlout the present tudy.

1. Adamovich, .A. The adaplSSR. 155 : 707-710, 196~.

2. Adamovich, .A. and A. .hypothalarnus (Diencephalon

3. Guttmann, L. and D. Whiwinj u ries. Brain, 70 : 366-401

4. Iggo, A. Tension receptors1955.

5. Koshino, K. Action potentizrostra! part of the medulla

6. Mukherjee, S.R. Effect ofof splanchnic and buffer nl

7. Samonina, G.E. and M.G. Lnerves in the course of vi!

8. Sherrington, C.S. On the sp9. Watkins, A.L. Reflex res po

bladder and rectum. Alii.

I October 1973 Volume Hnd. J. PhysioJ. Pharmac. "umber 4

n of hollow viscera like uraters of nictitating membrane

~n re~orted (9). Paraplegicsistension of urinary bladderladder in the cat. This res-nervation and was abolished

riod of 30 to 60 seconds onof distension. At low dis-pressure was raised above

aded distension and abrupthe results in these situationsd distension in exteriorisednging between 7 to 25 mmbuted to stimulation of pro-ay work in stimulation ofncrease in the volume ofessure the volume of thebladder increase with theise in exteriorised bladder. ,lmportant part in stimu-

ntravesical pressure. Thee of intravesical volume.

(1) and later by Koshinositive to abrupt stretch ,ue to stimulation of thesebeen reported (2). The

are more abundant in the

e present work showed athat level for 15 minilised below the pretes~ceptors showed the phe-have been published by

Blood Pressure During Distension of Bladder 375

The effect of graded distension after bilateral vagotomy, ganglion blockade and reserpimsa-tion are showin in Fig. 4. The rise of blood pressure is more marked and statiscally highlysigni-ficant following vagotomy. This may be due to removal of buffer mechanism of the vagus nervesresulting in considerable rise of blood pressure on graded distension following vagotomy agreeingwith results of other workers (6,7).

The rise of blood pressure on distension of bladder is reported to be brought about by splan-chnic vasoconstriction and active vasoconstriction in the renal circulation reflexly and this reflexresponse was abolished after bilateral splanchnicotomy (6). Ganglion blockade was done in thepresent study to decrease the total systemic vascular resistance and splanchnic blood flow thus redu-cing the blood pressure. Graded distension of urinary bladder after ganglion blockade and afterreserpinisation showed a rise of blood pressure which is suggestive of some vasoconstrictor humoralsubstance released in the circulation. Cross circulation studies and catecholamine levels in theblood before and after distension of bladder may be able to throw some light on the mechanismof pressor response.

ACKNOWLEDGEMENT

The authors wish to thank Dr. M. N. Saha and P. Gopinath for their constant help thorough-out the present study.

REFERE CES

1. Adamovich, N.A. The adaptation of the mechanoreceptors of the urinary bladder. DOKL AKAD NAUKSSR. 155 : 707-710, 1964.

2. Adamovich, N.A. and A.N. Borgest. Afferent effects of the stimulation of bladder receprois on thehypothalamus (Diencephalon. Brain). Byul. Eksp. Bioi. Med., 60 : 15-19, 1965.

3. Guttmann, L. and D. Whitteridge, Effect of bladder distension on automatic mechanisms "fin spiral cordinjuries. Brain, 70 : 366-404, 1947.

4. Iggo, A. Tension receptors in the stomach and the urinary bladder. J. Physiol. (London) 128 : 593-6071955. '

5. Koshino, K. Action potentials corresponding to the change of the intravesical pressure in the pons and therostra! part of the medulla of the cat. Osaka Daigaku Igak u Zasshi, 15 : 23-27, 1963.

6. Mukherjee, S.R. Effect of bladder distension on arterial blood pressure arid renal circulation. Roleof splanchnic and buffer nerves. J. Physiol. (London), 138 : 307-325, 1957.

7. Samonina, G.E. and M.G. Udel.'Nov. Electrophysiological analysis of activity in cardiac branches of vagusnerves in the course of viscero-cardiac reflexes. Federation Proc., (Tram. suppl), 24 : :67-570, 1965.

8. Sherrington, C.S. On the spinal animal (Marshal! Hall prize address.), Med. Chir. Trans., 82 : 449-477,1899.9. Watkins, A.L. Reflex responses of the nictitating membrane and the blood pressure to distension of the

bladder and rectum. Am. J. Pliysiol., 121 : 32-39, 1938.

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