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A new swivel for double infusion of fluids into rats
Physiology & Behavior, Vol. 27, pp. 175-177. Pergamon Press and Brain Research Publ., 1981. Printed in the U.S.A.
A N e w Swivel for Double Infusion of Fluids into Rats P E T R U S C. V I N K A N D F E R D I N A N D
ROELFSEMA 1
D e p a r t m e n t o f Endocrinology, University Hospital, Leiden, the Netherlands R e c e i v e d 31 O c t o b e r 1980 VINK, P. C. AND F. ROELFSEMA. A new swivel for double infusion of fluids into rats. PHYSIOL. BEHAV. 27(1) 175-177, 1981.--A new double swivel for long-term infusion of fluids into rats is described. It is characterized by compact design, light weight and low torque. Double swivel
Infusion
Rats
AS PART o f an investigation of the circadian rhythms of urinary electrolyte excretion in rats, we needed a double swivel for the intragastric infusion of fluids as well as the intravenous infusion of corticosteroids into adrenalectomized rats. At the time only two double swivels had been described [ 1,2] which might possibly be incorporated in our system [3]. However, attempts to construct the first type were unsuccessful because the torque was too high and the swivel tended to leak under conditions of negative pressure; the second was too large, although basically sound as far as construction design was concerned. For most of our experiments over a 4-year period we had used a single infusion swivel [4] which proved to be very reliable, therefore we attempted to modify the design of this swivel; on the basis of these modifications, we have constructed a new type of double infusion swivel which has a low torque and is also leak-proof, airtight and highly reliable.
DESIGN Materials used were the following: disposable needles (Henke, Tuttlingen, Fed. Rep. Germany): 22 ga (0.70×50 mm), 20 ga (0.90x50 mm), 18 ga (1.2x50 mm). Stainless steel tubing, type AISI 321, o.d. 2.00 mm, i.d. 1.60 mm; stainless steel rods, type AIS1303, diameter: 15, 7, 6 and 5 mm (Bernet, Amsterdam, the Netherlands); aluminum rod, type 51ST, diameter: 19 mm. Teflon rod (PTFE, Pampus, Schiefbahn, Fed. Rep. Germany) diameter: 5 mm. Ball bearing, cat. no. 623, 22 AV (F.A.G., Klagenfurt, Fed. Rep. Germany). A scale drawing of the swivel is shown in Fig. 1 and the blueprint plan in Fig. 2. The central channel is formed by needle 1 (30.5×0.7 mm), which is soldered to needle 2 (21 x 1.2 mm). Needle 2 is soldered to a gland 3 which fits into the stuffing box 4. The largest diameter of the stuffing box is
15 mm, the length is 36 mm. The two packing discs 5 (o.d. 4.9 mm, i.d. 0.7 ram, height 2.0 mm) and the sleeve 6 (o.d. 4.9 mm, i.d. 1.0, height 3.0 mm) define a chamber in which the stationary part of needle 1 butts against the rotary part. When sufficient force is applied to the packing discs via the gland 3 this chamber is closed. The rotary part of needle l is soldered at point 20 to needle 8. The inlet tube of the second channel is formed by needle 9 (I0×0.7 ram) which is soldered to needle 10 (24x 1.2 mm). Needle 10 fits into an excentrically bored channel in the stuffing box. This channel opens into a central chamber l l . The outlet of this chamber is formed by needle 8 (58x2.0 mm) and the rotary part of needle 1 (48×0.7 mm) runs through the center of these parts. Chamber 11 is closed by packing disc 12 (o.d. 3.9 mm, i.d. 2.1 mm, height 1.5 mm) and gland 13. Needle 8 is soldered to the ball bearing holder 14, on which ball bearing 15 has been mounted. The ball bearing fits smoothly in the stuffing box for disassembly. The aluminium sleeve nut 16 secures the rotary part of the swivel to the stuffing box. The outlet tube of the second channel, needle 19 (10x0.7 mm), is soldered at point 20 to needle 8. The flange is screwed tightly onto part 13 by setscrew 17. On this flange is soldered tube 18 which serves as a fixation point for the protective coil with the two polyethylene tubes. The total weight of the swivel amounts to 55 g, and thus it can easily be counterbalanced. During fabrication of this swivel it is mandatory to make teflon rings that are precisely concentric. Furthermore it is very important to cut the needles without deforming them. The swivel is checked for leaks by forcing fluid through the channels, both under positive and negative pressure. The torque, measured at TNO, Netherlands Organization for Applied Scientific Research, Delft, was found to be 33-+6.0 g ram. In comparison the torque of the single infusion swivel was 13.9-+2.11 g mm. The force required to rotate the swivel, and thus acting on the rat's skull, was 3.38 g for the double swivel and 1.73 g for the single infusion swivel.
1Address correspondence and request for reprints to Dr. F. Roelfsema, Department of Endocrinology, University Hospital, Leiden, the Netherlands.
C o p y r i g h t © 1981 B r a i n R e s e a r c h P u b l i c a t i o n s Inc.--0031-9384/81/070175-03502.00/0
176
VINK AND ROELFSEMA
lO
11 12 13 14 15 16
17ml8 20
19 lcm
FIG. 1. A scale drawing of the double swivel. The numbers are referred to in the text.
DISCUSSION The advantage of our swivel is its compact design. The force required for rotating does not place any strain on the rat's skull and a simple counterbalance is sufficient for the vertical movements. The swivel can easily be disassembled and reassembled in case radioactive or toxic substances have been infused. Recently, two other infusion swivels have been described. The advantage of these swivels is that they are easily assembled from parts available in any laboratory without
machining. However one of the swivels [5] on close examination is not a double but a single joint swivel. The other [6] has a much higher torque than our swivel, when tested under comparable conditions. In order to test the system in vivo, 16 male adrenalectomized rats, weighing 220-240 g, were continuously infused for 5 weeks. One catheter was placed in the stomach, according to the technique of Geary [7], the other in the right atrium. The outlets of the two silicon tubes were connected to 2 bent needles, which were fixed to the skull with the aid of 4 stainless steel screws and dental cement. During this period,
DOUBLE INFUSION SWIVEL
177
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T E FLON TEFLON
S.S.
TEFLON
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2 O
15
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~1.2
. . . .
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I1
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i
~
--e2 00.7
,. I9
'
TIN-@5x4
15
FIG. 2. Blueprint plan of the double swivel. Dimensions are in mm. Most parts are made of stainless steel (S.S.). AI is aluminium. The black parts are tinsolder.
in which 30 ml of 2.5% glucose solution w e r e infused daily via the intragastric tube and adrenal steroids w e r e administered via the intravenous c a t h e t e r (2.5 ml/day), no malfunctioning o f the swivels occurred. The b e h a v i o r of the rats was normal (by observation) and the m e a n increase in body
weight was 3.5 g/day, which is normal for our inbred strain of Wistar rats at this age. T h e r e are many applications of this c o m p a c t swivel for physiological or pharmacological studies, such as infusing two substances simultaneously via different routes or infusing and blood sampling at the same time.
REFERENCES 1. Nicolaidis, S., N. Rowland, M.-J. Meile, P. Marfaing-Jallat and A. Pesez. A flexible technique for long term infusions in unrestrained rats. Pharmac. Biochem. Behav. 2: 131-136, 1974. 2. Brandstaetter, J. and J. Terkel. Adaptation of a double swivel for cross-transfusion. Behav. Res. Meth. lnstrum. 7:11-14, 1975. 3. Roelfsema, F., D. van der Heide and D. Smeenk. Circadian rhythms of urinary electrolyte excretion in freely moving rats. Life Sci. 27: 2203-2209, 1980. 4. Steiger, E., H. M. Vars and S. J. Dudrick. A technique for longterm intravenous feeding in unrestrained rats. Archs Surg., Chicago 11)4: 330-332, 1972.
5. Darracq, C., P. Gonzalez and C. Balabaud. Double and single swivel joints for infusions and/or body fluid collections of free moving animals. Physiol. Behav. 25: 327-329, 1980. 6. Blair, R., B. Fishman, Z. Amit and J. R. Weeks. A simple double channel swivel for infusions of fluids into unrestrained animals. Pharmac. Biochem. Behav. 12: 463-466, 1980. 7. Geary, N. Intragastric cannulation procedures and rat's food intake and body weight maintenance. Physiol. Behav. 19: 185-190, 1977.
A N e w Swivel for Double Infusion of Fluids into Rats P E T R U S C. V I N K A N D F E R D I N A N D
ROELFSEMA 1
D e p a r t m e n t o f Endocrinology, University Hospital, Leiden, the Netherlands R e c e i v e d 31 O c t o b e r 1980 VINK, P. C. AND F. ROELFSEMA. A new swivel for double infusion of fluids into rats. PHYSIOL. BEHAV. 27(1) 175-177, 1981.--A new double swivel for long-term infusion of fluids into rats is described. It is characterized by compact design, light weight and low torque. Double swivel
Infusion
Rats
AS PART o f an investigation of the circadian rhythms of urinary electrolyte excretion in rats, we needed a double swivel for the intragastric infusion of fluids as well as the intravenous infusion of corticosteroids into adrenalectomized rats. At the time only two double swivels had been described [ 1,2] which might possibly be incorporated in our system [3]. However, attempts to construct the first type were unsuccessful because the torque was too high and the swivel tended to leak under conditions of negative pressure; the second was too large, although basically sound as far as construction design was concerned. For most of our experiments over a 4-year period we had used a single infusion swivel [4] which proved to be very reliable, therefore we attempted to modify the design of this swivel; on the basis of these modifications, we have constructed a new type of double infusion swivel which has a low torque and is also leak-proof, airtight and highly reliable.
DESIGN Materials used were the following: disposable needles (Henke, Tuttlingen, Fed. Rep. Germany): 22 ga (0.70×50 mm), 20 ga (0.90x50 mm), 18 ga (1.2x50 mm). Stainless steel tubing, type AISI 321, o.d. 2.00 mm, i.d. 1.60 mm; stainless steel rods, type AIS1303, diameter: 15, 7, 6 and 5 mm (Bernet, Amsterdam, the Netherlands); aluminum rod, type 51ST, diameter: 19 mm. Teflon rod (PTFE, Pampus, Schiefbahn, Fed. Rep. Germany) diameter: 5 mm. Ball bearing, cat. no. 623, 22 AV (F.A.G., Klagenfurt, Fed. Rep. Germany). A scale drawing of the swivel is shown in Fig. 1 and the blueprint plan in Fig. 2. The central channel is formed by needle 1 (30.5×0.7 mm), which is soldered to needle 2 (21 x 1.2 mm). Needle 2 is soldered to a gland 3 which fits into the stuffing box 4. The largest diameter of the stuffing box is
15 mm, the length is 36 mm. The two packing discs 5 (o.d. 4.9 mm, i.d. 0.7 ram, height 2.0 mm) and the sleeve 6 (o.d. 4.9 mm, i.d. 1.0, height 3.0 mm) define a chamber in which the stationary part of needle 1 butts against the rotary part. When sufficient force is applied to the packing discs via the gland 3 this chamber is closed. The rotary part of needle l is soldered at point 20 to needle 8. The inlet tube of the second channel is formed by needle 9 (I0×0.7 ram) which is soldered to needle 10 (24x 1.2 mm). Needle 10 fits into an excentrically bored channel in the stuffing box. This channel opens into a central chamber l l . The outlet of this chamber is formed by needle 8 (58x2.0 mm) and the rotary part of needle 1 (48×0.7 mm) runs through the center of these parts. Chamber 11 is closed by packing disc 12 (o.d. 3.9 mm, i.d. 2.1 mm, height 1.5 mm) and gland 13. Needle 8 is soldered to the ball bearing holder 14, on which ball bearing 15 has been mounted. The ball bearing fits smoothly in the stuffing box for disassembly. The aluminium sleeve nut 16 secures the rotary part of the swivel to the stuffing box. The outlet tube of the second channel, needle 19 (10x0.7 mm), is soldered at point 20 to needle 8. The flange is screwed tightly onto part 13 by setscrew 17. On this flange is soldered tube 18 which serves as a fixation point for the protective coil with the two polyethylene tubes. The total weight of the swivel amounts to 55 g, and thus it can easily be counterbalanced. During fabrication of this swivel it is mandatory to make teflon rings that are precisely concentric. Furthermore it is very important to cut the needles without deforming them. The swivel is checked for leaks by forcing fluid through the channels, both under positive and negative pressure. The torque, measured at TNO, Netherlands Organization for Applied Scientific Research, Delft, was found to be 33-+6.0 g ram. In comparison the torque of the single infusion swivel was 13.9-+2.11 g mm. The force required to rotate the swivel, and thus acting on the rat's skull, was 3.38 g for the double swivel and 1.73 g for the single infusion swivel.
1Address correspondence and request for reprints to Dr. F. Roelfsema, Department of Endocrinology, University Hospital, Leiden, the Netherlands.
C o p y r i g h t © 1981 B r a i n R e s e a r c h P u b l i c a t i o n s Inc.--0031-9384/81/070175-03502.00/0
176
VINK AND ROELFSEMA
lO
11 12 13 14 15 16
17ml8 20
19 lcm
FIG. 1. A scale drawing of the double swivel. The numbers are referred to in the text.
DISCUSSION The advantage of our swivel is its compact design. The force required for rotating does not place any strain on the rat's skull and a simple counterbalance is sufficient for the vertical movements. The swivel can easily be disassembled and reassembled in case radioactive or toxic substances have been infused. Recently, two other infusion swivels have been described. The advantage of these swivels is that they are easily assembled from parts available in any laboratory without
machining. However one of the swivels [5] on close examination is not a double but a single joint swivel. The other [6] has a much higher torque than our swivel, when tested under comparable conditions. In order to test the system in vivo, 16 male adrenalectomized rats, weighing 220-240 g, were continuously infused for 5 weeks. One catheter was placed in the stomach, according to the technique of Geary [7], the other in the right atrium. The outlets of the two silicon tubes were connected to 2 bent needles, which were fixed to the skull with the aid of 4 stainless steel screws and dental cement. During this period,
DOUBLE INFUSION SWIVEL
177
24
0 3
7
°o.~ I
Tm - /
II
02
01.2
3
0
3
15 1B.5
7 10
36 0 1.5
~-.~j.~.~ Ibl0 E L 3
02
N.-,,.~ L-,F,.9 N-o,.9
.~ , 5
M5
~:
@ 3.9 _-.J~.- - @2.1
<
T E FLON TEFLON
S.S.
TEFLON
15 12
2 O
15
' 11 .,. iLL..... @t~5
~1.2
. . . .
s.s.__:. 3,5
~-
0
21
1
L, ....
- T ~ - r i. - I
05
~
@2,9
27
I
30 M3~---@15
B
2 0
'°;--~_
I
@3EL3
_
o
@2.5
S.S.
14 I
0
. TIN
0
~
S.S~ 11
°,.2
- e
_
AL.
3
9
°
- -7-~
I,~,
0
I1
El" &.-TIN
i
~
--e2 00.7
,. I9
'
TIN-@5x4
15
FIG. 2. Blueprint plan of the double swivel. Dimensions are in mm. Most parts are made of stainless steel (S.S.). AI is aluminium. The black parts are tinsolder.
in which 30 ml of 2.5% glucose solution w e r e infused daily via the intragastric tube and adrenal steroids w e r e administered via the intravenous c a t h e t e r (2.5 ml/day), no malfunctioning o f the swivels occurred. The b e h a v i o r of the rats was normal (by observation) and the m e a n increase in body
weight was 3.5 g/day, which is normal for our inbred strain of Wistar rats at this age. T h e r e are many applications of this c o m p a c t swivel for physiological or pharmacological studies, such as infusing two substances simultaneously via different routes or infusing and blood sampling at the same time.
REFERENCES 1. Nicolaidis, S., N. Rowland, M.-J. Meile, P. Marfaing-Jallat and A. Pesez. A flexible technique for long term infusions in unrestrained rats. Pharmac. Biochem. Behav. 2: 131-136, 1974. 2. Brandstaetter, J. and J. Terkel. Adaptation of a double swivel for cross-transfusion. Behav. Res. Meth. lnstrum. 7:11-14, 1975. 3. Roelfsema, F., D. van der Heide and D. Smeenk. Circadian rhythms of urinary electrolyte excretion in freely moving rats. Life Sci. 27: 2203-2209, 1980. 4. Steiger, E., H. M. Vars and S. J. Dudrick. A technique for longterm intravenous feeding in unrestrained rats. Archs Surg., Chicago 11)4: 330-332, 1972.
5. Darracq, C., P. Gonzalez and C. Balabaud. Double and single swivel joints for infusions and/or body fluid collections of free moving animals. Physiol. Behav. 25: 327-329, 1980. 6. Blair, R., B. Fishman, Z. Amit and J. R. Weeks. A simple double channel swivel for infusions of fluids into unrestrained animals. Pharmac. Biochem. Behav. 12: 463-466, 1980. 7. Geary, N. Intragastric cannulation procedures and rat's food intake and body weight maintenance. Physiol. Behav. 19: 185-190, 1977.