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Glucose concentrations in parotid fluid and blood serum following intravenous glucose loading
Section
by the
ARMED .
.
.
FORCES .
.
GLUCOSE SERUM
.
.
AND
PUBLIC
.
.
l
.
CONCENTRATIONS FOLLOWING
.
HEALTH .
.
IN PAROTID
INTRAVENOUS
Ira L. Shannon, Major, USAF (MSC), and Robert A. Brooks,
.
.
SERVICE .
FLUID
GLUCOSE
l
.
AND
.
.
.
.
.
BLOOD
LOADING
(DC), John R. Prigmore, Captain, USAF (MC)
Captain,
USAF
T
HE question of whether or not glucose is present in saliva has long been a Our interest in this particular question point of research controversy. was twofold; we were concerned with (1) the obvious implications of the presence of varying amounts of glucose in saliva in relation to present-day concepts of caries etiology and (2) the need for a clearer understanding of the seemingly very specific characteristics of glandular permeability to glucose. Although attempts have been made to measure human salivary glucose by older and less sensitive methods that were not specific for this variable, we know of no studies carried out on this fluid with specific enzyme and/or automatic dialysis methods. It was our purpose in the present study to ascertain the presence or absence of glucose in human parotid fluid by sampling specimens from fasting subjects and by carrying out conventional intravenous glucose-tolerance tests in blood serum and parotid fluid.
MATERIALS
AND
METHODS
Eight fasting male subjects between the ages of 17 and 22 years, each physically qualified for military service, served as subjects. Each was given 50 ml. of a 50 per cent aqueous glucose solution intravenously over a two- to threeminute period. Blood was withdrawn prior to the injection and ten, thirty, sixty, and 120 minutes after completion of the injection. Following a ten-minute accommodation period, a ten-minute parotid fluid sample was collected under gum base” (sugar-free) stimulation prior to glucose administration, and continuous stimulation provided a series of six ten-minute postglucose samples. From the *American
School Chicle
of Aviation Company.
Medicine,
Brooks 1010
Air
Force
Base.
Texas.
GLUCOSE
CONCENTRATIONS
TN
PAROTID
1011
FLUID
Later parotid fluid samples were collected 120 and 180 minutes after glucosce administration. All samples were analyzed for glucose by an automated ferricyanide method1 and by the glucose oxidase procedure.2 RESTJLTS
AND
DISCUSSION
The mean values for all glucose determinations are shown in Table I. The finding that glucose levels were considerably higher with the ferricyanide method than with the enzyme procedure is in accord with the literature.“) 4 Of primary interest is the identification of the additive ferricyanide-reducing substance( s j present in parotid fluid. When parotid fluid samples arc treated with trichloroacetic acid and then dialyzed automatically, the ferricyanide method gives lower results that more nearly agree with those that follow the enzyme procedure. Thus, it seems possible that this additive substance is the same interfering substance that produces turbidity with molybdate, even after dialysis, in inorganic: phosphate determinations.l Regardless of the type of chemical determination employed, the glucose concentration pattern of parot.id fluid paralleled that of the blood serum, these responses being similar in nature to our previous parotid fluid adrenocortical steroid findings.5, G We have now analyzed 140 fastine parotid fluid specimens by both these methods, and, without fail, we have founti a, measurable level of glucose. Although it is clear that the automated method is measuring reducing substance other than true glucose, either of these methods may be used in intravenous glucose-tolerance work, since the gross responses art the same. If the findings of the present study are verified in diabetic patients, parotid fluid must then be seriously considered for routine use in the clinical laboratory in carbohpdrat,e metabolism evaluations. I.
TABLE
COMPARISON
10 20 30 40 50 60 120 180
FERRICYANIDE IN SERUM AND
AND ENZYME METHODS PAROTID FI.TJID
FOR Cr~vcos~
---.
3IINUTES AFTER INTRAVEKOUS GLUCOSE
0
OF AUTOMATIC DETERMINATION
GLUCOSE
(SIG.
PER
SERUM AUTOANALYZER
s
82.9
1 GLUCOSE
’
PAROTID OXIDASE
68.5
188.0
159.9
103.0
83.7
86.0 95.4
1
66.3 75.5
__-
CENT)
AUTOANALYZER
FLUID 1 GLUCOSE
1.03 2.06 1.81 1.09 1.06 1.05 1.05 1.05 1.04
OXIDASE
--_-.
.60 1.15 .78 .43 .40 .40 .42 .41 30
SUMMARY
Glucose oxidase and automated ferricyanide healthy young men indicated the following :
procedures
carried
out on
1. There is a measurable level of glucose in human fasting parotid saliva. 2. This parotid-fluid glucose concentration is sensitive to the a,dministration of intravenous glucose and closely parallels the serum level.
1012 The authors D. Weiss for their
SHANNON, express technical
appreciation assistance.
PRIGMORE, to J.
AND F.
M&near,
OS., O.M. & O.P. .~II,QlSt. 1960
BROOKS E.
D. Dinger,
L.
Crawford,
and
REFERENCES 1. Shannon, Ira L., and Prigmore, John R.: The Automatic Determination of Calcium, Inorganic Phosphate, Urea Nitrogen, and Glucose in Parotid Fluid, School of Aviation Medicine, USAF Report No. 60-49, April, 1960 (To be published in Ann. New York Acad. Se.). 2. Keston, 8. A.: Specific Calorimetric Enzymatic Analytical Reagents for Glucose, Papers of the 129th Meeting of the ACS, April, 1956, p. 31C. 3. Huggett, A. St. G., and Nixon, D. A.: Use of Glucose Oxidase, Peroxidase, and o-Dianisidine in Determination of Blood and Urinary Glucose, Lancet 273: 368, 1957. 4. Saifer, A., and Gerstenfeld, S.: The Photometric Micro-determination of Blood Glucose With Glucose Oxidase, J. Lab. & Clin. Med. 51: 448, 1958. 5. Shannon, Ira L., Prigmore, John R., Brooks, Robert A., and Feller, Ralph P.: The 17. Hydroxycorticosteroids of Parotid Flmd, Serum and Urine Following Intramuscular Administration of Repository Corticotropin, J. Clin. Endocrinol. 19: 1477, 1959. 6. Shannon, Ira L., Prigmore, John R., Brooks, Robert A., and Feller, R. P.: Parotid Saliva, Serum and Urine 17.Hydroxycorticosteroids Following a Two-Hour Intravenous Infusion of Adrenoeorticotropin, J. D. Res. 38: 1237, 1959.
by the
ARMED .
.
.
FORCES .
.
GLUCOSE SERUM
.
.
AND
PUBLIC
.
.
l
.
CONCENTRATIONS FOLLOWING
.
HEALTH .
.
IN PAROTID
INTRAVENOUS
Ira L. Shannon, Major, USAF (MSC), and Robert A. Brooks,
.
.
SERVICE .
FLUID
GLUCOSE
l
.
AND
.
.
.
.
.
BLOOD
LOADING
(DC), John R. Prigmore, Captain, USAF (MC)
Captain,
USAF
T
HE question of whether or not glucose is present in saliva has long been a Our interest in this particular question point of research controversy. was twofold; we were concerned with (1) the obvious implications of the presence of varying amounts of glucose in saliva in relation to present-day concepts of caries etiology and (2) the need for a clearer understanding of the seemingly very specific characteristics of glandular permeability to glucose. Although attempts have been made to measure human salivary glucose by older and less sensitive methods that were not specific for this variable, we know of no studies carried out on this fluid with specific enzyme and/or automatic dialysis methods. It was our purpose in the present study to ascertain the presence or absence of glucose in human parotid fluid by sampling specimens from fasting subjects and by carrying out conventional intravenous glucose-tolerance tests in blood serum and parotid fluid.
MATERIALS
AND
METHODS
Eight fasting male subjects between the ages of 17 and 22 years, each physically qualified for military service, served as subjects. Each was given 50 ml. of a 50 per cent aqueous glucose solution intravenously over a two- to threeminute period. Blood was withdrawn prior to the injection and ten, thirty, sixty, and 120 minutes after completion of the injection. Following a ten-minute accommodation period, a ten-minute parotid fluid sample was collected under gum base” (sugar-free) stimulation prior to glucose administration, and continuous stimulation provided a series of six ten-minute postglucose samples. From the *American
School Chicle
of Aviation Company.
Medicine,
Brooks 1010
Air
Force
Base.
Texas.
GLUCOSE
CONCENTRATIONS
TN
PAROTID
1011
FLUID
Later parotid fluid samples were collected 120 and 180 minutes after glucosce administration. All samples were analyzed for glucose by an automated ferricyanide method1 and by the glucose oxidase procedure.2 RESTJLTS
AND
DISCUSSION
The mean values for all glucose determinations are shown in Table I. The finding that glucose levels were considerably higher with the ferricyanide method than with the enzyme procedure is in accord with the literature.“) 4 Of primary interest is the identification of the additive ferricyanide-reducing substance( s j present in parotid fluid. When parotid fluid samples arc treated with trichloroacetic acid and then dialyzed automatically, the ferricyanide method gives lower results that more nearly agree with those that follow the enzyme procedure. Thus, it seems possible that this additive substance is the same interfering substance that produces turbidity with molybdate, even after dialysis, in inorganic: phosphate determinations.l Regardless of the type of chemical determination employed, the glucose concentration pattern of parot.id fluid paralleled that of the blood serum, these responses being similar in nature to our previous parotid fluid adrenocortical steroid findings.5, G We have now analyzed 140 fastine parotid fluid specimens by both these methods, and, without fail, we have founti a, measurable level of glucose. Although it is clear that the automated method is measuring reducing substance other than true glucose, either of these methods may be used in intravenous glucose-tolerance work, since the gross responses art the same. If the findings of the present study are verified in diabetic patients, parotid fluid must then be seriously considered for routine use in the clinical laboratory in carbohpdrat,e metabolism evaluations. I.
TABLE
COMPARISON
10 20 30 40 50 60 120 180
FERRICYANIDE IN SERUM AND
AND ENZYME METHODS PAROTID FI.TJID
FOR Cr~vcos~
---.
3IINUTES AFTER INTRAVEKOUS GLUCOSE
0
OF AUTOMATIC DETERMINATION
GLUCOSE
(SIG.
PER
SERUM AUTOANALYZER
s
82.9
1 GLUCOSE
’
PAROTID OXIDASE
68.5
188.0
159.9
103.0
83.7
86.0 95.4
1
66.3 75.5
__-
CENT)
AUTOANALYZER
FLUID 1 GLUCOSE
1.03 2.06 1.81 1.09 1.06 1.05 1.05 1.05 1.04
OXIDASE
--_-.
.60 1.15 .78 .43 .40 .40 .42 .41 30
SUMMARY
Glucose oxidase and automated ferricyanide healthy young men indicated the following :
procedures
carried
out on
1. There is a measurable level of glucose in human fasting parotid saliva. 2. This parotid-fluid glucose concentration is sensitive to the a,dministration of intravenous glucose and closely parallels the serum level.
1012 The authors D. Weiss for their
SHANNON, express technical
appreciation assistance.
PRIGMORE, to J.
AND F.
M&near,
OS., O.M. & O.P. .~II,QlSt. 1960
BROOKS E.
D. Dinger,
L.
Crawford,
and
REFERENCES 1. Shannon, Ira L., and Prigmore, John R.: The Automatic Determination of Calcium, Inorganic Phosphate, Urea Nitrogen, and Glucose in Parotid Fluid, School of Aviation Medicine, USAF Report No. 60-49, April, 1960 (To be published in Ann. New York Acad. Se.). 2. Keston, 8. A.: Specific Calorimetric Enzymatic Analytical Reagents for Glucose, Papers of the 129th Meeting of the ACS, April, 1956, p. 31C. 3. Huggett, A. St. G., and Nixon, D. A.: Use of Glucose Oxidase, Peroxidase, and o-Dianisidine in Determination of Blood and Urinary Glucose, Lancet 273: 368, 1957. 4. Saifer, A., and Gerstenfeld, S.: The Photometric Micro-determination of Blood Glucose With Glucose Oxidase, J. Lab. & Clin. Med. 51: 448, 1958. 5. Shannon, Ira L., Prigmore, John R., Brooks, Robert A., and Feller, Ralph P.: The 17. Hydroxycorticosteroids of Parotid Flmd, Serum and Urine Following Intramuscular Administration of Repository Corticotropin, J. Clin. Endocrinol. 19: 1477, 1959. 6. Shannon, Ira L., Prigmore, John R., Brooks, Robert A., and Feller, R. P.: Parotid Saliva, Serum and Urine 17.Hydroxycorticosteroids Following a Two-Hour Intravenous Infusion of Adrenoeorticotropin, J. D. Res. 38: 1237, 1959.