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Hematuria following midbrain lesions in the rat
EXPERIMENTAL
NEUROLOGY
Hematuria ROBERT
6,
349-356
Following
(1962)
Midbrain
Lesions
GEORGE, WILFORD L. HASLETT,
in the
Rat
AND PETER LOMAXI
Department of Pharmacology, University of California Medical Center, Los Angeles, California Received
June
4, 1962
Bilateral electrolytic lesions were placed in the midbrains of fifty rats. Hematuria occurred whenever the lesions involved the dorsomedial midbrain tegmenturn between the levels of the red nucleus and the caudal border of the inferior colliculus. Lesians outside this area were without effect. The hematuria appeared within 20 to 30 hours after placement of the lesions and usually was associated with distention of the bladder. There were multiple hemorrhagic areas in the bladder mucosa. Microscopically, edema and hemorrhages involving all layers of the bladder wall were seen, with occasional pin-point, acute ulcerations of the mucosa. The kidneys and ureters were normal. We suggest that these changes are the result of destruction of parasympathetic pathways in the dorsal tegmentum which then may lead to unopposed sympathetic activity. Introduction
During an investigation of the effect of midbrain lesions on druginduced tremor in rats, it was noticed that some animals were passing bloody urine. These animals showed little spontaneousactivity and some remained in coma. A similar syndrome of drowsiness and hypokinesia has been described in cats ( 1, 2) and monkeys (3, 11) with lesions involving the periaqueductal gray matter. Similarly, pathological sleepiness has been reported (10) in rats with electrolytic lesionsof the midbrain tegmentum. However, in none of these studies was hematuria observed. Methods
Brain lesions were made in Sprague-Dawley rats of either sex; all animals weighed from 200 to 250 gm. The same unipolar, stainless steel 1 This work was supported by USPHS Grant B-3007. Dr. Peter Lomax is a Visiting Assistant Professor from the Department of Physiology, University of Manchester, England. We would like to thank Dr. M. A. Verity, of the Department of Pathology, UCLA Medical Center, for assistance and advice with the histological investigations. 349
3.50
GEORGE,
HASLETT,
AND
LOMAX
electrode was used throughout, being positioned with a Krieg-Johnson stereotaxic instrument with the animal under Methohexital (Brevital) anesthesia (35-45 mg/kg). The lesions were anodal, using a constant current of 2 ma for either 10 or 1.5sec. 3
FIG. 1. Midline sagittal section of rat midbrain. Hatched area represents the most rostra1 and caudal limits of lesions in animals developing hematuria. Stippled area represents periaqueductal gray matter. Abbreviations: Cb, cerebellum; Cer, cerebrum; IC, inferior colliculus; MB, mamillary body; P, pons; RN, red nucleus; SC, superior colliculus; III, third ventricle; VI, nucleus abducens.
The animals were killed with chloroform one to eleven days following operation and the abdominal viscera were examined for macroscopical changes.The kidneys, ureters, and bladders were fixed in Bouin’s solution and paraffin sections made. Brains were perfused via the carotid arteries with normal saline solution, then perfused and fixed with formalin ( 10%). Lesions were reconstructed by cutting either frozen or paraffin sections, 15 to 30 p thick, at appropriate intervals. All tissues were stained with either hematoxylin and eosinor by the Weil method.
Bilateral, symmetrical lesions were placed in the midbrains of fifty rats, in an area bounded rostrally by the posterior hypothalamus and caudally by the middle of the pons. Frank hematuria occurred only in
HEMATURIA
351
AND BRAIN LESIONS
the thirteen animals with lesionsof the dorsomedial midbrain tegmentum, between the levels of the red nucleus and the caudal border of the inferior colliculus (Fig. 1). The lesions were within 1.5 mm of the midline and impinged upon the periaqueductal gray matter or the adjacent floor of the fourth ventricle. Representative sections from nine of these animals are
TF 0 00
A
C
$5
FIG. 2. Coronal sections at centers of lesions in nine animals developing hematuria. Section A corresponds to plane 1 in Fig. 1; Sections B-F, to 2; and Sections G-J, to 3. Solid areas indicate microscopical extent of lesions. Abbreviations: BP, brachium pontis; ML, medial lemniscus; MLF, medial longitudinal fasciculus; PG, periaqueductal gray matter ; IV, fourth ventricle.
shown diagrammatically in Fig. 2. Lesions rostra1 or caudal to these levels, in the remaining thirty-seven rats, failed to produce any urinary changes. Photomicrographs of midbrain sections of two animals with (A and B) and one without (C) hematuria can be seen in Fig. 3. Composite drawings of midbrain lesions producing hematuria and those without effect are compared in Fig. 4.
352
GEORGE,
of FIG :. 3. Photomicrographs develt oped hematuria, C did not.
HASLETT,
three
animals
AND
with
LOMAX
midbrain
lesions;
A
and
B
HEMATURIA
AND
BRAIN
LESIONS
353
Animals with positive lesions showed signs of hematuria 20 to 30 hours after the lesions were made. Prior to the appearance of blood, the fur over the abdomen and perineum became soaked in urine. Sometimes a prominent bulging of the lower abdominal wall was seen, denoting bladder distention. On macroscopical examination, the bladders usually were distended, contained heavily blood-stained urine, and when opened showed multiple hemorrhages of the mucosa with adherent blood clots. The stomachs, intestines, kidneys, and ureters appeared normal, except for one animal which, after 11 days, developed hydroureters and hydronephrosis.
FIG. 4. Composite diagrams of all lesions centered on plane 2, Fig. 1. Black area in A is the region destroyed in animals developing hematuria; B shows the extent of lesions in control animals. Note sparing of periaqueductal gray in 8.
Histologically, 24 hours following placement of the lesions, the renal parenchyma, calyces, and ureters appeared normal. Free red cells were present in the vesical cavity. The bladder epithelium was for the most part intact, except for rare, acute focal erosions of the transitional epithelium. There was marked congestion, edema,and hemorrhage of the submucosa, with infiltration of red cells through the muscularis and epithelium (Fig. 5). The middle circular and innermost muscle layers appeared irregularly contracted, throwing the mucosainto folds. Some of the other effects which were observed in most of the rats were varying degreesof hypokinesia, ataxia, paresis and circling, together with aphagia and adipsia. The hypokinesia was most marked with the more rostra1 lesions, at the level of the red nucleus, and resembledpathological sleep similar to that described by Nauta (10). In another group of eighty-seven rats, lesions were placed in the
354
GEORGE,
HASLETT,
AND
LOMAX
FIG. 5. Photomicrograph of the bladder of a rat with hematuria. Area within the circle shows marked congestion and hemorrhage of the submucosa. Arrows point to free red blood cells in the vesical cavity.
diencephalon, globus pallidus and throughout the corpus striatum. In none of these animalswas hematuria present. Discussion
The results clearly indicate that dorsomedial tegmental lesions involving the periaqueductal gray matter or the adjacent floor of the fourth ventricle lead to hemorrhagic cystitis in the rat. On the basis of our findings it is difficult to explain the mechanismby which lesions of the central nervous system may produce hematuria. However, previous investigations suggest two possible mechanisms.The first of these concerns the role of the midbrain in the micturition reflex. Barrington (5) first described a center in the upper pons which exerts a powerful facilitatory effect on the micturition reflex in decerebrate cats. Later Tang and Ruth (12) localized this center to the tegmentum just lateral to the central gray at the caudal superior collicular level, and found that
HEMATURIA
AND
BRAIN
LESIONS
35.5
its destruction led to abolition of the micturition reflex. Further evidence for a midbrain micturition controlling area is the study of Kabat, Magoun, and Ranson (7) who found that electrical stimulation of this region in the cat resulted in increased tonic contractions of the bladder. They suggested that this effect could be due to activation of parasympathetic pathways. The results of Barlow and Root (4) have indicated that increased intravesical pressure may lead to hematuria. They observed that when the feline bladder is suddenly distended with a volume of water sufficient to produce a high intravesical pressure (in excess of 80 cm of water), there is cleavage of the mucosa along the lines of the vessels along with submucosal hemorrhages and disruption of the muscle layers. It seems unlikely that such a mechanism can explain our observations for the following reasons: (a) the positions of our lesions do not correspond with those that Tang and Ruth found to be effective in abolishing the micturition reflex in the cat; (b) no sudden increase in pressure would occur under the conditions of our experiments, nor is it likely that pressures of this magnitude would arise in the absence of obstruction to urinary outflow; (c) bladder distention was not apparent in all of the animals with hematuria; and (d) the bladder walls in our animals do not present the same histological picture of extensive vesical necrosis as those described above in cats, following sudden bladder distention. The other possible mechanism is one analogous to that suggested by French and his associates (6) to explain the occurrence of gastrointestinal hemorrhages following the placement of anterior hypothalamic lesions. Their view is that the posterior hypothalamus subserves sympathetic functions and when it is unopposed, as is the case following anterior hypothalamic lesions, there occurs a predominance of sympathetic activity, resulting in gastric hemorrhages. This view is substantiated by their finding that the administration of a sympathetic blocking agent prevents gastrointestinal mucosal bleeding. The studies of Keller (8) provide further support for such a mechanism. He noted gastrointestinal submucosal hemorrhages in dogs after destruction of the anterior hypothalamus but was unable to detect submucosal bleeding in any dogs which had been sympathectomized previously. From the above data, it seems possible that destruction of central parasympathetic pathways results in a predominance of sympathetic activity, causing bladder hemorrhages.
356
GEORGE,
HASLETT,
AND
LOMAX
The findings of Lange and Rieger (9) are somewhat in agreement with our results. They reported hematuria in 124 of 450 patients treated for head injuries. In six of these patients other injuries, such as fractures of the pelvis, were implicated as the cause. Cystoscopy was carried out in “some of the patients with hematuria” and revealed petechial hemorrhages and ecchymoses of the bladder mucosa. No indication of the nature or site of the brain damage was given. In view of our results it would seem possible that the hematuria was the result of midbrain damage. References 1. 2. 3. 4. 5. 6.
7.
8.
9. 10.
11. 12.
BAILEY, P. 1948. Alteration of behaviour produced in cats by lesions in the brain stem. J. Nervous Mental Disease 107 (4) : 336-339. BAILEY, P., and E. W. DAVIS. 1942. Effects of lesions of the periaqueductal gray matter in the cat. PYOC. Sot. Exptl. Biol. Med. 61: 305-306. BAILEY, P., and E. W. DAVIS. 1944. Effect of the periaqueductal gray matter of the Macaca Mulatta. J. Neuropathol. Exptl. Neurol. 3: 69-72. BARLOW, C. M., and W. S. ROOT. 1952. Caloric technique for measuring blood flow in the feline bladder. Am. J. Physiol. 171: 554-557. BARRINGTON, F. J. F. 1928. The central control of micturition. Bruin 61: 209-220. FRENCH, J. D., R. W. PORTER, F. K. VON AMERONGEN, and R. B. PAVEY, 1952. Gastrointestinal hemorrhage and ulceration associated with intracranial lesions. Surgery 32: 395-407. KABAT, H., H. W. MAGOUN, and S. W. RANSON. 1935. Reaction of the bladder to stimulation of points in the forebrain and midbrain. J. Camp. Neural. 63: 211-239. KELLER, A. D. 1936. Protection by peripheral nerve section of the gastrointestinal tract from ulceration following hypothalamic lesions. A.M.A. Arch. Pathol. 21: 165-184. LANGE, K., and H. RIEGER. 1960. SchIdeltrauma und Hzmaturie. Chirurg 31: 216-218. NAUTA, W. J. H. 1946. Pathological sleepiness in rats as a result of lesions in the caudal hypothalamus or in the rostra1 midbrain tegmentum. J. Neurophysiol. 9: 285-316. PETERSON, E. W., H. W. MAGOUN, W. S. MCCULLOCH, and D. B. LINDSLEY. 1949. Production of postural tremor. J. Neurophysiol. l!4: 371-384. TANG, P. C., and T. C. RUCH. 1956. Localisation of brain stem and diencephalic areas controlling the micturition reflex. J. Comp. Neural. 106: 213-245.
NEUROLOGY
Hematuria ROBERT
6,
349-356
Following
(1962)
Midbrain
Lesions
GEORGE, WILFORD L. HASLETT,
in the
Rat
AND PETER LOMAXI
Department of Pharmacology, University of California Medical Center, Los Angeles, California Received
June
4, 1962
Bilateral electrolytic lesions were placed in the midbrains of fifty rats. Hematuria occurred whenever the lesions involved the dorsomedial midbrain tegmenturn between the levels of the red nucleus and the caudal border of the inferior colliculus. Lesians outside this area were without effect. The hematuria appeared within 20 to 30 hours after placement of the lesions and usually was associated with distention of the bladder. There were multiple hemorrhagic areas in the bladder mucosa. Microscopically, edema and hemorrhages involving all layers of the bladder wall were seen, with occasional pin-point, acute ulcerations of the mucosa. The kidneys and ureters were normal. We suggest that these changes are the result of destruction of parasympathetic pathways in the dorsal tegmentum which then may lead to unopposed sympathetic activity. Introduction
During an investigation of the effect of midbrain lesions on druginduced tremor in rats, it was noticed that some animals were passing bloody urine. These animals showed little spontaneousactivity and some remained in coma. A similar syndrome of drowsiness and hypokinesia has been described in cats ( 1, 2) and monkeys (3, 11) with lesions involving the periaqueductal gray matter. Similarly, pathological sleepiness has been reported (10) in rats with electrolytic lesionsof the midbrain tegmentum. However, in none of these studies was hematuria observed. Methods
Brain lesions were made in Sprague-Dawley rats of either sex; all animals weighed from 200 to 250 gm. The same unipolar, stainless steel 1 This work was supported by USPHS Grant B-3007. Dr. Peter Lomax is a Visiting Assistant Professor from the Department of Physiology, University of Manchester, England. We would like to thank Dr. M. A. Verity, of the Department of Pathology, UCLA Medical Center, for assistance and advice with the histological investigations. 349
3.50
GEORGE,
HASLETT,
AND
LOMAX
electrode was used throughout, being positioned with a Krieg-Johnson stereotaxic instrument with the animal under Methohexital (Brevital) anesthesia (35-45 mg/kg). The lesions were anodal, using a constant current of 2 ma for either 10 or 1.5sec. 3
FIG. 1. Midline sagittal section of rat midbrain. Hatched area represents the most rostra1 and caudal limits of lesions in animals developing hematuria. Stippled area represents periaqueductal gray matter. Abbreviations: Cb, cerebellum; Cer, cerebrum; IC, inferior colliculus; MB, mamillary body; P, pons; RN, red nucleus; SC, superior colliculus; III, third ventricle; VI, nucleus abducens.
The animals were killed with chloroform one to eleven days following operation and the abdominal viscera were examined for macroscopical changes.The kidneys, ureters, and bladders were fixed in Bouin’s solution and paraffin sections made. Brains were perfused via the carotid arteries with normal saline solution, then perfused and fixed with formalin ( 10%). Lesions were reconstructed by cutting either frozen or paraffin sections, 15 to 30 p thick, at appropriate intervals. All tissues were stained with either hematoxylin and eosinor by the Weil method.
Bilateral, symmetrical lesions were placed in the midbrains of fifty rats, in an area bounded rostrally by the posterior hypothalamus and caudally by the middle of the pons. Frank hematuria occurred only in
HEMATURIA
351
AND BRAIN LESIONS
the thirteen animals with lesionsof the dorsomedial midbrain tegmentum, between the levels of the red nucleus and the caudal border of the inferior colliculus (Fig. 1). The lesions were within 1.5 mm of the midline and impinged upon the periaqueductal gray matter or the adjacent floor of the fourth ventricle. Representative sections from nine of these animals are
TF 0 00
A
C
$5
FIG. 2. Coronal sections at centers of lesions in nine animals developing hematuria. Section A corresponds to plane 1 in Fig. 1; Sections B-F, to 2; and Sections G-J, to 3. Solid areas indicate microscopical extent of lesions. Abbreviations: BP, brachium pontis; ML, medial lemniscus; MLF, medial longitudinal fasciculus; PG, periaqueductal gray matter ; IV, fourth ventricle.
shown diagrammatically in Fig. 2. Lesions rostra1 or caudal to these levels, in the remaining thirty-seven rats, failed to produce any urinary changes. Photomicrographs of midbrain sections of two animals with (A and B) and one without (C) hematuria can be seen in Fig. 3. Composite drawings of midbrain lesions producing hematuria and those without effect are compared in Fig. 4.
352
GEORGE,
of FIG :. 3. Photomicrographs develt oped hematuria, C did not.
HASLETT,
three
animals
AND
with
LOMAX
midbrain
lesions;
A
and
B
HEMATURIA
AND
BRAIN
LESIONS
353
Animals with positive lesions showed signs of hematuria 20 to 30 hours after the lesions were made. Prior to the appearance of blood, the fur over the abdomen and perineum became soaked in urine. Sometimes a prominent bulging of the lower abdominal wall was seen, denoting bladder distention. On macroscopical examination, the bladders usually were distended, contained heavily blood-stained urine, and when opened showed multiple hemorrhages of the mucosa with adherent blood clots. The stomachs, intestines, kidneys, and ureters appeared normal, except for one animal which, after 11 days, developed hydroureters and hydronephrosis.
FIG. 4. Composite diagrams of all lesions centered on plane 2, Fig. 1. Black area in A is the region destroyed in animals developing hematuria; B shows the extent of lesions in control animals. Note sparing of periaqueductal gray in 8.
Histologically, 24 hours following placement of the lesions, the renal parenchyma, calyces, and ureters appeared normal. Free red cells were present in the vesical cavity. The bladder epithelium was for the most part intact, except for rare, acute focal erosions of the transitional epithelium. There was marked congestion, edema,and hemorrhage of the submucosa, with infiltration of red cells through the muscularis and epithelium (Fig. 5). The middle circular and innermost muscle layers appeared irregularly contracted, throwing the mucosainto folds. Some of the other effects which were observed in most of the rats were varying degreesof hypokinesia, ataxia, paresis and circling, together with aphagia and adipsia. The hypokinesia was most marked with the more rostra1 lesions, at the level of the red nucleus, and resembledpathological sleep similar to that described by Nauta (10). In another group of eighty-seven rats, lesions were placed in the
354
GEORGE,
HASLETT,
AND
LOMAX
FIG. 5. Photomicrograph of the bladder of a rat with hematuria. Area within the circle shows marked congestion and hemorrhage of the submucosa. Arrows point to free red blood cells in the vesical cavity.
diencephalon, globus pallidus and throughout the corpus striatum. In none of these animalswas hematuria present. Discussion
The results clearly indicate that dorsomedial tegmental lesions involving the periaqueductal gray matter or the adjacent floor of the fourth ventricle lead to hemorrhagic cystitis in the rat. On the basis of our findings it is difficult to explain the mechanismby which lesions of the central nervous system may produce hematuria. However, previous investigations suggest two possible mechanisms.The first of these concerns the role of the midbrain in the micturition reflex. Barrington (5) first described a center in the upper pons which exerts a powerful facilitatory effect on the micturition reflex in decerebrate cats. Later Tang and Ruth (12) localized this center to the tegmentum just lateral to the central gray at the caudal superior collicular level, and found that
HEMATURIA
AND
BRAIN
LESIONS
35.5
its destruction led to abolition of the micturition reflex. Further evidence for a midbrain micturition controlling area is the study of Kabat, Magoun, and Ranson (7) who found that electrical stimulation of this region in the cat resulted in increased tonic contractions of the bladder. They suggested that this effect could be due to activation of parasympathetic pathways. The results of Barlow and Root (4) have indicated that increased intravesical pressure may lead to hematuria. They observed that when the feline bladder is suddenly distended with a volume of water sufficient to produce a high intravesical pressure (in excess of 80 cm of water), there is cleavage of the mucosa along the lines of the vessels along with submucosal hemorrhages and disruption of the muscle layers. It seems unlikely that such a mechanism can explain our observations for the following reasons: (a) the positions of our lesions do not correspond with those that Tang and Ruth found to be effective in abolishing the micturition reflex in the cat; (b) no sudden increase in pressure would occur under the conditions of our experiments, nor is it likely that pressures of this magnitude would arise in the absence of obstruction to urinary outflow; (c) bladder distention was not apparent in all of the animals with hematuria; and (d) the bladder walls in our animals do not present the same histological picture of extensive vesical necrosis as those described above in cats, following sudden bladder distention. The other possible mechanism is one analogous to that suggested by French and his associates (6) to explain the occurrence of gastrointestinal hemorrhages following the placement of anterior hypothalamic lesions. Their view is that the posterior hypothalamus subserves sympathetic functions and when it is unopposed, as is the case following anterior hypothalamic lesions, there occurs a predominance of sympathetic activity, resulting in gastric hemorrhages. This view is substantiated by their finding that the administration of a sympathetic blocking agent prevents gastrointestinal mucosal bleeding. The studies of Keller (8) provide further support for such a mechanism. He noted gastrointestinal submucosal hemorrhages in dogs after destruction of the anterior hypothalamus but was unable to detect submucosal bleeding in any dogs which had been sympathectomized previously. From the above data, it seems possible that destruction of central parasympathetic pathways results in a predominance of sympathetic activity, causing bladder hemorrhages.
356
GEORGE,
HASLETT,
AND
LOMAX
The findings of Lange and Rieger (9) are somewhat in agreement with our results. They reported hematuria in 124 of 450 patients treated for head injuries. In six of these patients other injuries, such as fractures of the pelvis, were implicated as the cause. Cystoscopy was carried out in “some of the patients with hematuria” and revealed petechial hemorrhages and ecchymoses of the bladder mucosa. No indication of the nature or site of the brain damage was given. In view of our results it would seem possible that the hematuria was the result of midbrain damage. References 1. 2. 3. 4. 5. 6.
7.
8.
9. 10.
11. 12.
BAILEY, P. 1948. Alteration of behaviour produced in cats by lesions in the brain stem. J. Nervous Mental Disease 107 (4) : 336-339. BAILEY, P., and E. W. DAVIS. 1942. Effects of lesions of the periaqueductal gray matter in the cat. PYOC. Sot. Exptl. Biol. Med. 61: 305-306. BAILEY, P., and E. W. DAVIS. 1944. Effect of the periaqueductal gray matter of the Macaca Mulatta. J. Neuropathol. Exptl. Neurol. 3: 69-72. BARLOW, C. M., and W. S. ROOT. 1952. Caloric technique for measuring blood flow in the feline bladder. Am. J. Physiol. 171: 554-557. BARRINGTON, F. J. F. 1928. The central control of micturition. Bruin 61: 209-220. FRENCH, J. D., R. W. PORTER, F. K. VON AMERONGEN, and R. B. PAVEY, 1952. Gastrointestinal hemorrhage and ulceration associated with intracranial lesions. Surgery 32: 395-407. KABAT, H., H. W. MAGOUN, and S. W. RANSON. 1935. Reaction of the bladder to stimulation of points in the forebrain and midbrain. J. Camp. Neural. 63: 211-239. KELLER, A. D. 1936. Protection by peripheral nerve section of the gastrointestinal tract from ulceration following hypothalamic lesions. A.M.A. Arch. Pathol. 21: 165-184. LANGE, K., and H. RIEGER. 1960. SchIdeltrauma und Hzmaturie. Chirurg 31: 216-218. NAUTA, W. J. H. 1946. Pathological sleepiness in rats as a result of lesions in the caudal hypothalamus or in the rostra1 midbrain tegmentum. J. Neurophysiol. 9: 285-316. PETERSON, E. W., H. W. MAGOUN, W. S. MCCULLOCH, and D. B. LINDSLEY. 1949. Production of postural tremor. J. Neurophysiol. l!4: 371-384. TANG, P. C., and T. C. RUCH. 1956. Localisation of brain stem and diencephalic areas controlling the micturition reflex. J. Comp. Neural. 106: 213-245.