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Replacement and Absorption of Cerebrospinal Fluid in Normal and Vitamin a Deficient Calves
REPLACEMENT
AND ABSORPTION
NORMAL AND VITAMIN
OF CEREBROSPINAL A DEFICIENT
FLUID
IN
CALVES
M. OI~AMOTO, J. BITMAN, H. C. CECIL, M. R. CONNOLL¥, R. W. MILLER, AND, T. R. WRENN Dairy Cattle Research Branch, U. S. Department of Agrieu]ture, Beltsville, Maryland SUMMARY
Cerebrospinal fluid (CSF) replacement and absorption were measured in vitamin A deficient and nornml calves. Eeplacement estimates involved removal of CSF and determination of the time necessary to replace the volunm removed, and absorption estimates involved reinjection of the fluid and estimation of the time necessary to absorb this volmne. Thirty-five minutes were required to replace the 3.0 ml of CSF in the normal animals, as compared to 15 rain in the deficient calves. When estimating absorption capacity in the deficient calves, the CSF pressure was highly stable in 11 of the 12 experiments and the trials were terminated between 25-60 rain. With normal calves the pressures returned to the original level in 17 nfin. The results suggest that underabsorption represents a greater factor than overproduction as a cause of increased CSF pressure in vitamin A deficient calves.
One of the initial effects of vitamin A deficiency is an increased cerebrospinal fluid (CSF) pressure (8). The mechanism whereby the increase in CSF pressure is brought about has been the subject of many previous investigations. The British investigators, Millen and Woolam (7), have reviewed their extensive studies in rabbits and chicks on the relationship of the increased CSF pressure in the hydrocephalus caused by vitamin A deficiency. They have concluded that overproduction of CSF occurred, although no measurements of the rates of appearance or departure of CSF constituents were made to support this interpretation. Indeed, underabsorption of CSF could have produced the same results. I n this country, a group of workers at the Storrs, Connecticut, Agricultural Experiment Station have investigated the osmotic relationships of vitamin A deficiency and the CSF (5, 6). The biochemical constituents of sermn, CSF, and aqueous humor were studied, because any changes in composition could have important osmotic effects and could bring about the increased CSF pressure. The authors concluded that the increased CSF pressure observed in hypovitaminotic A calves was due to a greater volume of fluid within the spinal fluid system. They could not distinguish between overproduction or underabsorption, however, as a causative factor, and there were only very slight changes in any of the constituents studied. Received for publication March 3, 1962. 882
Whether overproduction or underabsorption of the CSF is the primary factor responsible for the increase in pressure in vitamin A deficiency has been difficult to deternfine. I n previous studies from this laboratory, no differences were observed in the rate of transfer of SCN from the blood to the CSF in normal and vitamin A deficient calves (1). However, when SCN was introduced directly into the CSF, a slower rate of disappearance was found in the deficient animals, suggesting a slower rate of CSF absorption (2). The purpose of the present study was to estimate more directly CSF replacement and absorption by a technique described by Schaltenbrand (9, 10). This involves removal of CSF mid determination of the time necessary to replace the volume removed, and secondly, reinjection of the fluid and estimation of the time necessary to absorb this volume. M A T E R I A L S AND METHODS
Treatment of the five normal and eight vitamin A deficient calves used in these experiments was the same as previously described (2). Use of" a CSF stopcock assembly enabled CSF pressure measurements to be nmde continuously during withdrawal and injection of fluid (Figures I and 2). Replacement of CSF. The C S F pressure was measured, a standard volume of CSF removed (3.0 ml), and the length of time necessary for the CSF pressure to return to its original level determined. The CSF pressure
CSF P R O D U C T I O N
F~a. 1. Measuring the dynamics of cerebrospinal replacement and absorption. The calf's head is restrained tightly against the fixed iron grid.
AND A B S O R P T I O N
883
during the course of the trial. The C S F pressure was highly stable and, a f t e r 25-60 rain, the experiments were terminated. The mean return time, therefore, ex(.eeds 38.7 rain and actually represents a mean nonreturn time. I t represents an average of the time periods in which the absorption experiments on the deficient calves were terminated, the C S F pressure showing little or no tendency to fall f r o m its elevated level. The absorption in milliliters p e r minute, therefore, is considerably less than 0.092, and more than 2.3 rain are required to absorb 1 ml of C S F . I t was our impression f r o m the slight or negligible decreases in pressure exhibite~ during the experiment that absorption was very slow in vitamin A deficient calves. Previous investigators have demonstrated that the effect of withdrawal of C S F is a sudden fall in the fluid pressure and that injection of fluid causes a r a p i d increase in C S F pressure (4). These changes and the initial compensatory reactions have been explained as being due to the response of the craniospinal vascular bed to withdrawal and injection of fluid f r o m the subarachnoid space. A f t e r the initial vascular reaction, the subsequent response has usually been attributed to the rate
was measured continuously and readings taken every 3 rain (deficient) or 5 rain (normal). This return time was an estimate of the replacement of the volume removed. Absorption of CSF. W h e n stable C S F pressure was reestablished, the previously removed 3.0 nfl of C S F were injected and the C S F pressure increased. The C S F pressure was measured continuously and readings were taken every 5 nlin (deficient) or every minute (nornlal). The time taken to return to the original pressure level was an estimate of the capacity of absorption. R E S U L T S AND D I S C U S S I O N
The data in Table 1 indicate marked differences in replacement and absorption of C S F between the normal and deficient animals. Thirty-five minutes were required to replace 3.0 ml of C S F in normal animals ss compared to only ]5 rain in the deficient calves. The rate of replacement was thus two to two and onehalf times more r a p i d in the vitamin A deficient calves. Estimates of' the absorption capacity indicated even larger differences. I n 11 of the 12 experiments in deficient calves, the pressure remained elevated a f t e r reinjection of C S F and did not return to the starting pressure
FIG. 2. Close-up illustrating stopcock and needle assembly. The CSF pressure has just been measured and a sample of fluid is being withdrawn. The adjustable needle stop near the skin surface prevents accidental penetration of the spinal cord.
1~. OKAlYIOTO ET AL
884
TABLE 1 Replacement and absorption of CSF in normal and vitamin A deficient calves I.
Replacement
Group Normal Deficient
mm CSF No. of mm CSF pressure experi- pressur~ ml CSF after merits at s t a r t removed removal 8 15
125 287
3 3
98 232
Min to retur~to starting pressure 35.2 + 14.0 a~ 15..5 -- 7.6
ml/min
min/ml
0.101 0.253
10.38 4.95
ml/min
min/ml
0.305 ~0.092"
5.40 ~12.31 ~
II. Absorption
Group Normal Deficient
mm CSF No. of mm CSF pressure experi- pressure ml CSF after ments at start injected injection 8 12
128 282
3 3
203 366
)¢Iin to r e t u r n to starting pressure 17.1 + 12.4 ~38.7~--+11.8
I n 11 of 12 experiments, CSF pressure did not return to the starting pressure and remained elevated, l~ore t h a n 38.7 rain is the mean nonreturn time and absorptions in the last two columns, therefore, are less and more than values shown. ~ Standard deviation. of p r o d u c t i o n a n d a b s o r p t i o n of the fluid. Thus, the S c h a l t e n b r a n d t e c h n i q u e utilized here includes the n e t effect of the v a s c u l a r r e s p o n s e a n d p r o d u c t i o n a n d a b s o r p t i o n of fluid. The results p r e s e n t e d suggest t h a t r e t a r d e d or f a u l t y physicochemieal a b s o r p t i o n of the C S F in the deficient calves was a g r e a t e r f a c t o r t h a n differences o b s e r v e d in r e - f o r m a t i o n of C S F . The r e t a r d e d a b s o r p t i o n observed in o u r s t u d y is in a g r e e m e n t with t r a c e r studies~ i n d i c a t i n g t h a t the increased fluid a n d p r e s s u r e in h y d r o c e p h a l u s is due to f a u l t y a b s o r p t i o n (3). I t is n o t possible to d i r e c t l y c o m p a r e t h e a b s o r p t i o n r a t e f o r n o r m a l a n d v i t a m i n A deficient calves. Such c o m p a r i s o n s of the abs o r p t i o n figures of T a b l e 1 are, t h e r e f o r e , misleading, because the deficient calves did n o t show a r e t u r n to o r i g i n a l pressures. T h e slower r a t e of a b s o r p t i o n of a b o u t t h r e e f o l d .305 3 . 3 ) would r e p r e s e n t only a mini.092 mum, a n d the rate is u n d o u b t e d l y r e t a r d e d to a significantly g r e a t e r degree t h a n is here indicated. I f the deficient calves h a d exhibited a b s o r p tion r a t e s of even 0.05 ml C S F / m i n , this would h a v e r e s u l t e d in some decline i n C S F p r e s s u r e . The results suggest t h a t a difference in a b s o r p tion c a p a c i t y r e p r e s e n t s a m u c h l a r g e r f a c t o r in i n c r e a s i n g C S F p r e s s u r e i n v i t a m i n A deficient calves t h a n f o r m a t i o n o f fluid. This indication agrees w i t h the p r e v i o u s l y observed slower r a t e of d i s a p p e a r a n c e of S C N f r o m the C S F in v i t a m i n A deficient calves (2).
REFERENCES (1) BITI~{AIq, J., CI~OlL, H. C., CONNOI~L~, M. R., ~/~ILL.F2R., R. W., OKA•OTO., ~VI., TIIO~IAS) J. W., A~D Wm~NN, T. R. Influx of Sodium Thiocyanate into Cerebrospinal Fluid in Normal and Vitamin A Deficient Calves. J. Dairy Sci., 45: 872. 1962. (2) BIT~AN, J., C~ClL, H. C., CON~OL~Y, M. R., ~¢~ILLFA~ R. W., OKKI~i0~r0', ~/~., AND WR~N~ T. R. Effect of Vitamin A Deficiency on Efflux of Sodium Thiocyanate from Corebrospinal Fluid. J-. Dairy Sei., 45: 879. 1962. (3) BOWS~IEa, D. Cerebrospinal Fluid Dynamics in Health and Disease. Chas. C Thomas, Springfield, Illinois. 1960. (4) DAVSON, H. Physiology of the Ocular and Cerebrospinal Fluids. Little, Brown and Co., Boston. I956. (5) DI~HOICI~Y, B. A., HAZZARD, D. G., EATON, H. D., GIClFO, A. P., Jic., ROUSSEAU, 5. E., Jic., ]:I:~L1VIBOLDT, C. F., .]-UNGHEPA~, E. L., ANI) GOSSLEB, D. G. Some Biochemical Constituents in Serum, Corebrospinal Fluid, and Aqueous Humor of Vitamin A Deficient Holstein Calves. J. Dairy Sci., 43: 630. 1960. (6) HAZZAI%D,D. G., GR.IFO, A. P., ,.TIC.,ROUSSEiAU, J. E., Jic., W0~L~BL, C. G., EATON, H. D., NIeLSeN, S. W., AND G0SSI~E~, D. G. Effect of Level of Ration Intake and Duration of Vitamin A Deficiency upon Some Biochemical Constituents in Serum, Cerebrospinal Fluid, and Aqueous Humor of Holstein Calves Fed Fixed Carotene Intakes. 5. Dairy Sci., 45: 91. 1962.
CSF PRODUCTION AND ABSORPTION (7) ~/[ILL]~N, J. W., AND WOOLAM, D. ~=[. ~ . I n The Cerebrospinal Fluid, p. 168. Ed., G. E. W. Wolstenholme and Cecelia M. O'Connor. Little, Brown and Co., Boston. 1958. (8) mOORE, L. A., AN]) SYlphS, J. F. Cerebrospinal Fluid Pressure and Vitamin A Deficiency. Am. J. Physiol., 130: 684. 1940.
885
(9) SCHA~NBr~AN]), G. Anatomie und Physiologie der Liquor Zirkulation. Arch. f. Ohren. l~asen w. Kehlkopfh. m. Ztschr. f. Hals-Nasen n. Ohrenh., 156: 1. 1949. (10) SCHALTENBI~AND, G. I n The Cerebrospinal Fluid, p. 186. Ed., G. E. W. Wolstenholme and Cecelia M. O'Connor. Little, Brown and Co., Boston. 1958.
AND ABSORPTION
NORMAL AND VITAMIN
OF CEREBROSPINAL A DEFICIENT
FLUID
IN
CALVES
M. OI~AMOTO, J. BITMAN, H. C. CECIL, M. R. CONNOLL¥, R. W. MILLER, AND, T. R. WRENN Dairy Cattle Research Branch, U. S. Department of Agrieu]ture, Beltsville, Maryland SUMMARY
Cerebrospinal fluid (CSF) replacement and absorption were measured in vitamin A deficient and nornml calves. Eeplacement estimates involved removal of CSF and determination of the time necessary to replace the volunm removed, and absorption estimates involved reinjection of the fluid and estimation of the time necessary to absorb this volmne. Thirty-five minutes were required to replace the 3.0 ml of CSF in the normal animals, as compared to 15 rain in the deficient calves. When estimating absorption capacity in the deficient calves, the CSF pressure was highly stable in 11 of the 12 experiments and the trials were terminated between 25-60 rain. With normal calves the pressures returned to the original level in 17 nfin. The results suggest that underabsorption represents a greater factor than overproduction as a cause of increased CSF pressure in vitamin A deficient calves.
One of the initial effects of vitamin A deficiency is an increased cerebrospinal fluid (CSF) pressure (8). The mechanism whereby the increase in CSF pressure is brought about has been the subject of many previous investigations. The British investigators, Millen and Woolam (7), have reviewed their extensive studies in rabbits and chicks on the relationship of the increased CSF pressure in the hydrocephalus caused by vitamin A deficiency. They have concluded that overproduction of CSF occurred, although no measurements of the rates of appearance or departure of CSF constituents were made to support this interpretation. Indeed, underabsorption of CSF could have produced the same results. I n this country, a group of workers at the Storrs, Connecticut, Agricultural Experiment Station have investigated the osmotic relationships of vitamin A deficiency and the CSF (5, 6). The biochemical constituents of sermn, CSF, and aqueous humor were studied, because any changes in composition could have important osmotic effects and could bring about the increased CSF pressure. The authors concluded that the increased CSF pressure observed in hypovitaminotic A calves was due to a greater volume of fluid within the spinal fluid system. They could not distinguish between overproduction or underabsorption, however, as a causative factor, and there were only very slight changes in any of the constituents studied. Received for publication March 3, 1962. 882
Whether overproduction or underabsorption of the CSF is the primary factor responsible for the increase in pressure in vitamin A deficiency has been difficult to deternfine. I n previous studies from this laboratory, no differences were observed in the rate of transfer of SCN from the blood to the CSF in normal and vitamin A deficient calves (1). However, when SCN was introduced directly into the CSF, a slower rate of disappearance was found in the deficient animals, suggesting a slower rate of CSF absorption (2). The purpose of the present study was to estimate more directly CSF replacement and absorption by a technique described by Schaltenbrand (9, 10). This involves removal of CSF mid determination of the time necessary to replace the volume removed, and secondly, reinjection of the fluid and estimation of the time necessary to absorb this volume. M A T E R I A L S AND METHODS
Treatment of the five normal and eight vitamin A deficient calves used in these experiments was the same as previously described (2). Use of" a CSF stopcock assembly enabled CSF pressure measurements to be nmde continuously during withdrawal and injection of fluid (Figures I and 2). Replacement of CSF. The C S F pressure was measured, a standard volume of CSF removed (3.0 ml), and the length of time necessary for the CSF pressure to return to its original level determined. The CSF pressure
CSF P R O D U C T I O N
F~a. 1. Measuring the dynamics of cerebrospinal replacement and absorption. The calf's head is restrained tightly against the fixed iron grid.
AND A B S O R P T I O N
883
during the course of the trial. The C S F pressure was highly stable and, a f t e r 25-60 rain, the experiments were terminated. The mean return time, therefore, ex(.eeds 38.7 rain and actually represents a mean nonreturn time. I t represents an average of the time periods in which the absorption experiments on the deficient calves were terminated, the C S F pressure showing little or no tendency to fall f r o m its elevated level. The absorption in milliliters p e r minute, therefore, is considerably less than 0.092, and more than 2.3 rain are required to absorb 1 ml of C S F . I t was our impression f r o m the slight or negligible decreases in pressure exhibite~ during the experiment that absorption was very slow in vitamin A deficient calves. Previous investigators have demonstrated that the effect of withdrawal of C S F is a sudden fall in the fluid pressure and that injection of fluid causes a r a p i d increase in C S F pressure (4). These changes and the initial compensatory reactions have been explained as being due to the response of the craniospinal vascular bed to withdrawal and injection of fluid f r o m the subarachnoid space. A f t e r the initial vascular reaction, the subsequent response has usually been attributed to the rate
was measured continuously and readings taken every 3 rain (deficient) or 5 rain (normal). This return time was an estimate of the replacement of the volume removed. Absorption of CSF. W h e n stable C S F pressure was reestablished, the previously removed 3.0 nfl of C S F were injected and the C S F pressure increased. The C S F pressure was measured continuously and readings were taken every 5 nlin (deficient) or every minute (nornlal). The time taken to return to the original pressure level was an estimate of the capacity of absorption. R E S U L T S AND D I S C U S S I O N
The data in Table 1 indicate marked differences in replacement and absorption of C S F between the normal and deficient animals. Thirty-five minutes were required to replace 3.0 ml of C S F in normal animals ss compared to only ]5 rain in the deficient calves. The rate of replacement was thus two to two and onehalf times more r a p i d in the vitamin A deficient calves. Estimates of' the absorption capacity indicated even larger differences. I n 11 of the 12 experiments in deficient calves, the pressure remained elevated a f t e r reinjection of C S F and did not return to the starting pressure
FIG. 2. Close-up illustrating stopcock and needle assembly. The CSF pressure has just been measured and a sample of fluid is being withdrawn. The adjustable needle stop near the skin surface prevents accidental penetration of the spinal cord.
1~. OKAlYIOTO ET AL
884
TABLE 1 Replacement and absorption of CSF in normal and vitamin A deficient calves I.
Replacement
Group Normal Deficient
mm CSF No. of mm CSF pressure experi- pressur~ ml CSF after merits at s t a r t removed removal 8 15
125 287
3 3
98 232
Min to retur~to starting pressure 35.2 + 14.0 a~ 15..5 -- 7.6
ml/min
min/ml
0.101 0.253
10.38 4.95
ml/min
min/ml
0.305 ~0.092"
5.40 ~12.31 ~
II. Absorption
Group Normal Deficient
mm CSF No. of mm CSF pressure experi- pressure ml CSF after ments at start injected injection 8 12
128 282
3 3
203 366
)¢Iin to r e t u r n to starting pressure 17.1 + 12.4 ~38.7~--+11.8
I n 11 of 12 experiments, CSF pressure did not return to the starting pressure and remained elevated, l~ore t h a n 38.7 rain is the mean nonreturn time and absorptions in the last two columns, therefore, are less and more than values shown. ~ Standard deviation. of p r o d u c t i o n a n d a b s o r p t i o n of the fluid. Thus, the S c h a l t e n b r a n d t e c h n i q u e utilized here includes the n e t effect of the v a s c u l a r r e s p o n s e a n d p r o d u c t i o n a n d a b s o r p t i o n of fluid. The results p r e s e n t e d suggest t h a t r e t a r d e d or f a u l t y physicochemieal a b s o r p t i o n of the C S F in the deficient calves was a g r e a t e r f a c t o r t h a n differences o b s e r v e d in r e - f o r m a t i o n of C S F . The r e t a r d e d a b s o r p t i o n observed in o u r s t u d y is in a g r e e m e n t with t r a c e r studies~ i n d i c a t i n g t h a t the increased fluid a n d p r e s s u r e in h y d r o c e p h a l u s is due to f a u l t y a b s o r p t i o n (3). I t is n o t possible to d i r e c t l y c o m p a r e t h e a b s o r p t i o n r a t e f o r n o r m a l a n d v i t a m i n A deficient calves. Such c o m p a r i s o n s of the abs o r p t i o n figures of T a b l e 1 are, t h e r e f o r e , misleading, because the deficient calves did n o t show a r e t u r n to o r i g i n a l pressures. T h e slower r a t e of a b s o r p t i o n of a b o u t t h r e e f o l d .305 3 . 3 ) would r e p r e s e n t only a mini.092 mum, a n d the rate is u n d o u b t e d l y r e t a r d e d to a significantly g r e a t e r degree t h a n is here indicated. I f the deficient calves h a d exhibited a b s o r p tion r a t e s of even 0.05 ml C S F / m i n , this would h a v e r e s u l t e d in some decline i n C S F p r e s s u r e . The results suggest t h a t a difference in a b s o r p tion c a p a c i t y r e p r e s e n t s a m u c h l a r g e r f a c t o r in i n c r e a s i n g C S F p r e s s u r e i n v i t a m i n A deficient calves t h a n f o r m a t i o n o f fluid. This indication agrees w i t h the p r e v i o u s l y observed slower r a t e of d i s a p p e a r a n c e of S C N f r o m the C S F in v i t a m i n A deficient calves (2).
REFERENCES (1) BITI~{AIq, J., CI~OlL, H. C., CONNOI~L~, M. R., ~/~ILL.F2R., R. W., OKA•OTO., ~VI., TIIO~IAS) J. W., A~D Wm~NN, T. R. Influx of Sodium Thiocyanate into Cerebrospinal Fluid in Normal and Vitamin A Deficient Calves. J. Dairy Sci., 45: 872. 1962. (2) BIT~AN, J., C~ClL, H. C., CON~OL~Y, M. R., ~¢~ILLFA~ R. W., OKKI~i0~r0', ~/~., AND WR~N~ T. R. Effect of Vitamin A Deficiency on Efflux of Sodium Thiocyanate from Corebrospinal Fluid. J-. Dairy Sei., 45: 879. 1962. (3) BOWS~IEa, D. Cerebrospinal Fluid Dynamics in Health and Disease. Chas. C Thomas, Springfield, Illinois. 1960. (4) DAVSON, H. Physiology of the Ocular and Cerebrospinal Fluids. Little, Brown and Co., Boston. I956. (5) DI~HOICI~Y, B. A., HAZZARD, D. G., EATON, H. D., GIClFO, A. P., Jic., ROUSSEAU, 5. E., Jic., ]:I:~L1VIBOLDT, C. F., .]-UNGHEPA~, E. L., ANI) GOSSLEB, D. G. Some Biochemical Constituents in Serum, Corebrospinal Fluid, and Aqueous Humor of Vitamin A Deficient Holstein Calves. J. Dairy Sci., 43: 630. 1960. (6) HAZZAI%D,D. G., GR.IFO, A. P., ,.TIC.,ROUSSEiAU, J. E., Jic., W0~L~BL, C. G., EATON, H. D., NIeLSeN, S. W., AND G0SSI~E~, D. G. Effect of Level of Ration Intake and Duration of Vitamin A Deficiency upon Some Biochemical Constituents in Serum, Cerebrospinal Fluid, and Aqueous Humor of Holstein Calves Fed Fixed Carotene Intakes. 5. Dairy Sci., 45: 91. 1962.
CSF PRODUCTION AND ABSORPTION (7) ~/[ILL]~N, J. W., AND WOOLAM, D. ~=[. ~ . I n The Cerebrospinal Fluid, p. 168. Ed., G. E. W. Wolstenholme and Cecelia M. O'Connor. Little, Brown and Co., Boston. 1958. (8) mOORE, L. A., AN]) SYlphS, J. F. Cerebrospinal Fluid Pressure and Vitamin A Deficiency. Am. J. Physiol., 130: 684. 1940.
885
(9) SCHA~NBr~AN]), G. Anatomie und Physiologie der Liquor Zirkulation. Arch. f. Ohren. l~asen w. Kehlkopfh. m. Ztschr. f. Hals-Nasen n. Ohrenh., 156: 1. 1949. (10) SCHALTENBI~AND, G. I n The Cerebrospinal Fluid, p. 186. Ed., G. E. W. Wolstenholme and Cecelia M. O'Connor. Little, Brown and Co., Boston. 1958.