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STUDIES IN METABOLISM: THE COLD PRESSOR TEST AS- A MEASURE OF VASOMOTOR IRRITABILITY
A Thesis Presented to the Faculty of the Department of Zoology The University of Southern California
In Partial Fulfillment of the Requirements of the Degree Master of Arts
by Nels Beals January 1950
UMI Number: EP67179
All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion.
UMI EP67179 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code
ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346
T h is thesis, w ritten by
under the guidance of h. is... F a c u lty Com m ittee, and app ro ved by a l l its members, has been presented to and accepted by the C o uncil on G raduate S tudy and Research in p a r t ia l f u l f i l l ment of the requirements f o r the degree of
MASTER OF ARTS
Dean D ate ......
TABLE OF CONTENTS PAGE I.
THE PROBLEM*......................... . . .
Statement of the problem* • • • • • * * • •
Justification of the problem.......... . .
Scope of the study* • « . * • • • * * • • • •
Organization of the remainder of the thesis . • • • • • • • •
of age on response • • • • • • •
of race on response. • • . • • •
of anethesia • • • . • • • • • •
REVIEW OF RELATED LITERATURE
Vascular hyperreactrtffcy and latent hyper tension* . • • • • * • * • • • • • • . • •
Vascular hyperreactivity and essential hypertension ♦ * . . . ♦
• • • • • • • • .
Mechanism of the cold pressor test. • • • • III.
METHOD OF STUDY. . . . . . . . . Apparatus Method of operation
• • • • • • • • • . . .
14 . . 15
histories. . • • • • • • • • • • • . *
of the subject. . . . . . .
CRITIQUE OF METHOD AND DISCUSSION............ 16 RECORD AND RESULTS OF EXPERIMENTS. . . . . .
ii CHAPTER VI*
PAGE SUMMARY* * * • • * • • .........
BIBLIOGRAPHY . * .......... • • • • * • * * • • • «
LIST OF TABLES TABLE I.
PAGE Arterial Pressure Rise Due to the Cold Pres sor Test of Seven Investigators............
Arterial Pressure in the Supine Position, Males, •
• • • • . • • • • . .
The Cold Pressor Test, Females.
Arterial Pressure Rise Due to Application of Males • • • « ...........
Arterial Pressure Rise Due to Application of Females
Effect of Different Agents on the Blood Pres sure Response to the Cold Test............
The Cold Pressor Test, Males.................
Arterial Pressure in the Supine Position, Females. ............
Response of Systolic Blood Pressure to Cold Test.........
CHAPTER I THE PROBLEM Statement of the problem#
This problem is an attempt
to study the reaction of the circulatory system when a por tion of it within the hand is subjected to cold conditions# Justification of the problem#
Since the cold pressor
test was first brought into prominence by Hines and Brown in 1932, it has been the center of much controversy as to its merits#
It was first held by Hines and Brown that the cold
pressor test was a standard test for predicting whether a person would develop hypertension or not#
Since their first
statement of the merits of the test, many investigators have repeated the test with varying techniques and have found disagreement in the conclusions of Hines and Brown.
thing, however, has been common to all of these investigations and that is that there is a change of blood pressure due to the introduction of cold as used in the cold pressor test. The purpose of this problem is to investigate the. blood pres sure changes resulting from the application of cold to a portion of the body. Scope of the study#
This study was made upon thirty
people selected at random and includes both sexes and has a wide range of ages#
Only subjects who are considered nor-
xn&l reactors are included in this study Organization of the remainder of the thesis. mainder of the thesis will consist of *
(a) Review of the
method and discussion; (d) Record and results of experiments and (e) Summary of the results of the problem.
related literature; (b) Method of study; (c) Critique of
CHAPTER II REVIEW OF RELATED LITERATURE There has been definite need for a standard stimulus to measure responses in blood pressure and vasomotor irrit ability,
Various procedures have been suggested and used, ~
Psychic and painful stimulation and electrical shocks have been used but they have not been satisfactory; the reaction of the subject Is too variable. There are several purposes for seeking a standard sti mulus to increase blood pressure.
The first purpose is to
group subjects according to the magnitude of their vasomotor responses of vasomotor Irritability,
The second purpose is
to ascertain,--if possible, whether a subject who is pre- disposed to hypertension has excessive vasomotor responses. If such can be ascertained, new concepts in the treatment 8 of hypertension may be formulated. Abnormal variability of the blood pressure is regarded by many authors as one of the outstanding characteristics of essential hypertension.
In the opinion of Hines and Brown
vascular hyperreaction, in persons with normal blood pressure means either a predisposition to hypertensive disease, or previous hypertension which Is temporarily latent.
observers, similarly, have emphasized the prognostic sig nificance of even transient elevation of the blood pressure
4 In subjects who generally have normal levels. Hyperreaction was found in 70.9 percent of the subjects who were likely to develop hypertension, as compared with only forty percent of those who were unlikely to develop it.sg This difference is statistically significant, and clearly In dicates that hyperresponse is more common among subjects des tined to develop the disease.
Nevertheless, the high inci
dence of vascular hyperreaction among non-hypertensive sub jects makes it equally apparent that no specific correlation exists between hyperresponse and subsequent hypertension. In this regard, it should be noted that the older the group considered, the less was the disparity in incidence of hyper reaction between the respective blood pressure groups.
cular hyperreaction, therefore, appears to arise, in later life at least, from factors related to the aging process.® The effect of age on response.
Pickering and Kissin in
1956, stated that, among patients with usually normal blood pressure the response of the pressure to stimulation by cold increases with age, and that, among elderly persons, the response of those who have essential hypertension is not greater than is that of patients who usually have normal blood pressure.18
However, these investigators studied
only nine elderly subjects with usually normal blood pressure and only twelve patients with essential hypertension.
is probably that in the investigation of Pickering and Kissin
5 the blood pressure of some of their patients with hyperten sion failed to reach a basal level* The effect of race on response *
The cold "stimulation
test" with modifications was applied to 325 young adults, 172 white patients and 153 negroes, approximately equally divided as to sex and ranging in age from fifteen to thirty-five years, with an average age of twenty-four years.
jects were free from cardiovascular disease and' had normal blood pressure. It was shown by this study that as the systolic blood pressure level is gradually raised, the percentage of negro a.
cases attaining a given level slowly begins to exceed that of the white subjects and as the higher elevations are reached the percentage difference progressively becomes more marked. From these observations it is concluded that there is a quantitative difference in the blood pressure reaction to a standard vasomotor stimulus In the white and negro races. This finding indicates that a hypersensitive vasomotor mechan ism is more frequently encountered in the negro race than in the white race. The effect of rest.
Hourly observations of blood pres
sure have shown that controlled mental and physical rest has a depressor effect on both the magnitude of the fluctuation and on the mean levels of systolic and diastolic pres stire in cases of essential hypertension.
Short periods of rest,
from twenty-four to forty-eight hours, had no significant effect on the response of the blood pressure to stimulation by cold
Long periods of rest, from one to two weeks,
might significantly diminish the vasomotor reaction.
resumption of activity the reaction returned to its previous 9 level. Effect of drugs.
Derivatives of barbituric acid have a
depressing effect on the reaction to cold.
Sodium amytal in
doses of three to six grains reduced the magnitude of the re action from fifty to one-hundred percent, and the reduction endwed from three to twelve hours•
The effect on the blood
pressure could be obtained without objective slowing of the psychic reactions.
Bromides were much less effective.
muth subnitrate given in doses of thirty grains daily for per iods as long as two weeks, had no effect on the reaction. *
Calcium chloride given intravenously in doses of 715 grains gave an increased response to the cold test, and a marked delay in the return of the blood pressure to the basal levels. Ethyl alcohol, given by mouth in doses of .5 cc for each kilo gram of body weight, reduced-the response to cold; the aver age decrease was ten percent.
The duration of the decrease
was from two to twelve hours.
The depressor effect of alco
hol was also demonstrable in the mean levels of systolic and diastolic pressure.
7 The effect of anesthesia*
General anesthesia caused
complete obliteration of the response*
produced a diminishing effect, roughly proportionate to the level of the anesthesia, and to the level of the systemic blood pressure*
With anesthesia, to the level of the nipple
line, the vasomotor response was less than normal.
gradual lowering of the level of anesthesia, the vasomotor reaction increased in magnitude to the pre-anesthetic level.^ Vascular hyperreactivity and essential hypertension* According to other data found in the.literature,5>s^,24*29>so other'workers have performed the cold pressor test, or a modification of it, on 827 subjects with usually normal blood pressure and on 276 patients with essential hyper tension.
The results show that the mean response of the
blood pressure of patients with essential hypertension to a standard stimulus is from two to six times greater than that of subjects with usually normal blood pressure.
data indicates, that vascular hyperreactivity, as measured by the cold pressor test, probably plays an important role -in the majority of cases of essential hypertension.
those subjects who at one time were normal hyperreactors but later developed essential hypertension, the range of response to the cold pressor test was increased as the 11 hypertension developed.
Vascular Hyperreactivity and latent hypertension,
reports on more than one-hundred individuals in the later deeades of life who had hypertensive changes in the retinal arterioles, hut whose blood pressure was usually normal and who gave no history of hypertension.
The blood pressure of
many of these patients was taken over a number of years, and they are known not to have had hypertension,
All gave evi
dence of having a hyperreactive vascular system, as measured by the cold pressor test.
These subjects were designated as
having latent hypertension and having attributed the vascular changes to the vascular hyperreactivity and not to hypertension earlier in life.3^ There is -a significant grovqp of persons who are known to have had hypertension bpt-whose blood pressures no longer are elevated, usually because of cardiac failure.
and Cwrb§? and Briggs and Oerting^ have studied the reactions of such patients to the cold pressor test and have found that the majority give hypertensive-type of reaction during the period when the blood pressure usually__.is normal.
it may be said of these patients that the hyperreaction to the cold pressor test is evidence of previous hypertension which is temporarily latent.
An investigation of the response to the cold pressor test of 256 members of thirty families revealed that* when both parents gave normal response to the test, none of the
children were hyperreactors or had hypertension.
parent had hypertension, or was a hyperreactor, and the other gave a normal response, 43 percent of the children were hyperreactors.
When hoth parents were hyperreactors,
95 percent of the children were hyperreactors. Briggs and p Oerting in their application of the cold pressor test to a group of 833 patients receiving prenatal care, found that the offspring of parents, hoth of whom had hypertension, always gave hyperreactions, hut that only two hyperreactors were found among subjects with no family history of hyper tension. Hines^ states that the purpose of his work was not to develop a method for predicting that hypertension would ap pear in the future in a given case, but to show'that there is an antecedent, or prehypertensive phase of essential hy pertension which has as its characteristic the same type of vascular hyperreactivity that is present in essential hyper* -
He considered that his work was an attempt to ex
plain the etiology of essential hypertension. Although the contentions strongly suggest the abnormal variability of the blood pressure is a heralding sign of subsequent hypertension, the observations of one investigator, Hussek, failed to support this concept.2^
In a study of
two hundred normal seamen over the age of 40 years, it was found that the cold pressor- reaction did not remain constant
10 throughout life, as alleged by Eines and Brown, but in creased appreciably with advancing age*
The augmented res
ponse, furthermore, applied not only to hyper reactors but also to hyporeactors (persons who showed a normal response more correctly, normal reactors) which Justifies the~conclusion that vascular reactivity increases a natural conse quence of the aging process.
From this it appeared that a
hyporeactor at 40 years might become a hyperreactor at 50 or 60 years of age*
Such a trend was further reflected in
the incidence of hyperreaction with succeeding decades.22 In their study of blood pressure using the cold pressor j
test as a standard stimulus Ayman and Goldshine,^ received differing results from those of Hines and Brown.
found that the response to the test in an individual was re markably constant from day to day, not varying more than 10 percent. Goldshine.
This was not found to be the case by Ayman and They obtained variations of response up to 100
percent on different visits, chiefly in hypertensive pat ients, despite starting the tests in such patients at the same level at each visit.
This has been true of both sys
tolic and diastolic levels although more frequent and marked in the former.
Such variations have occurred in tests re
peated within one hour.
Similarly, in a given patient,
test repeated at the same or at separate visits with a dif ferent basal level at each test did not necessarily result
11 in a similar ceiling level being made over a period of many months and no correlation was found between the range of the blood pressure response and the basal level at -the start of the test. Mechanism of the cold pressor test.
The most probable
explanation of the cause of jthe rise of blood pressure in the cold pressor test is that the response is a widespread vasopressor reaction initiated through a neurogenic reflex arc.
There is no significant change in cardiac rate or in
cardiac output during the test.
The speed of the reaction
and the fact that the reaction is present in completely adrenalectomized dogs and in human beings who have Addison*s disease, are proof that epinephrine is not the primary fac tor in producing the reaction.
The possibility of a local
hormonal subsistence being generated in the immersed hand as a result of the direct action of the cold is unlikely, as the reaction is not inhibited by a tourniquet placed around the arm so as to shut off the circulation. A conception is here presented that the abnormality of essential hypertension is an excessive response in the blood pressure to intrinsic and extrinsic stimulation. This abnormality is a heriditary one, which appears early in life and remains during life.
When the level of the
blood pressure is elevated and clinical degrees of hyper-
12 tension exist, the reactions then increase with increasing severity of the hypertension*
This hyperractive vasomotor
mechanism may be an important factor in the production of arteriolar hypertrophy and in the subsequent development of the organic stages of the disease. According to Hines and Brown,9 essential hypertension is a syndrome which develops upon the soil of a hyperreactive vasomotor system.
Subjects with vascular hypertonicity and
normal blood pressure are regarded by the authors as candi dates for the disease. The investigations of Chesley and A 0 Chesley, and Feldt and Wenstrand, on the other hand, ser iously open to question the significance of a hyperreactive response in the development of essential hypertension.
authors, in studies on a large number of cases, found no re lationship between the response to the cold pressor test and a family history of hypertensive cardiovascular disease. There has been considerable disagreement in some of the data obtained by the different investigators.
It is felt
that some of these differences could be explained on a basis of the latent variability of the blood pressure.
have the blood pressure taken may be a sufficient stimulus to bring it to a maximal level, but since the rise will be maximal in some instances and partial in others the results will not be comparable•
For this reason it was believed
that it would be of importance to study the range of var-
13 lability of the blood pressure as well as the actual pres sure at any given time.
CHAPTER III METHOD OF STUDY Apparatus.
Two pieces of apparatus were employed for
the registration of the systolic and the diastolic blood pressure during the course of this study. (a)
A tyeos sphygmomanometer consisting of a cuff, a
dial which is graduated in millimeters of mercury, and an inflator bulb. (b)
A binaural stethoscope.
Method of operation.
The sphygmomanometer cuff was put
on the subjects left arm above the elbow and it remained on the arm during the whole procedure, and when the lowest level of blood pressure was reached, the left hand was placed in a basin of water at a temperature of between four to five degrees Centigrade.
The water was tested at short intervals
during the recordings to insure the proper temperature.
hand was kept immersed to a level just above the wrist for sixty-seconds.
The blood pressure was measured at thirty
and sixty seconds*
The stethoscope was put against the
brachial artery and the systolic and diastolic pressures were made. The response Is recorded as the difference between the basal level and the maximum reading.
Using the criteria of
15 Hines and Brown, subjects whose response exceeded 22 mis systolic and 22 mm diastolic pressure were called hyperreactors.
This study doesn’t include these subjects.
whose response did not exceed these figures were designated as normal reactors or hyporeactors.
This study was made on
subjects who would all be classified as normal reactors. Preparation of the subject.
The subjects remained
recumbent in a quiet room and the pressure readings were taken over variable periods until a basal level was reached. The rest period was thirty minutes, and during this time three readings with the sphygmomanometer were made. Case histories.
None of the subjects reported that
they had hypertension or that any of their parents had hypertension.
Therefore, it is believed that all subjects
have a negative case history as far as hypertension is concerned.
CHAPTER IV CRITIQUE OF METHOD AND DISCUSSION A summary of the ntaaerous references to the cold pres sor test as recorded in the literature since it was brought into prominence by Hines and Brown in 1952 will reveal some interesting, although disturbing results. A study of Table I which was compiled from the work of seven investigators in the field of hypertension shows that there is considerable variation in the results*
even a variation in the results of the same investigator as in the case of Hines.9*10,12 An explanation for this wide variance in the literature might be explained by the following: (a)
Investigators have added some individual touch
to the technique of the test. (b)
Selection of subjects.
Condition of the arterial system
Interpretation of the data.
It is believed that an explanation of the data found in this paper is advisable at this time.
The data recorded
in this paper was found in Tables II and III show the re corded blood pressures of the males and female subjects respectively which have been used in this study.
17 ded in Tables II and III, each subject was given three tests for blood pressure and these were averaged and recorded under "Average" in the table.
In Table III under subject three and
four it is unfortunate that a third recording of their blood pressure was impossible so that their average blood pressure takes into consideration only two recordings. Tables IV and V record the blood pressures during the application of the cold water to the hands of the male and female"subjects respectively.
Recordings were taken at
thirty and sixty second intervals after the hand was put into the cold water.
In most cases the recording taken after the
hand was in the water sixty seconds was higher than after thirty seconds.
The "Average Ceiling" in Table IV and V is
the average of the recordings taken at the thirty and sixty second intervals. Table VI shows the arterial pressure rise due to the application of cold for the male subjects. is found the average arterial pressure.
In column one
This data was taken
from the average arterial pressure as recorded in Table II. The second column in Table VI shows the rise in arterial pressure after the cold was applied to the hand.
is taken from the column "Average Ceiling" in Table IV.
rise in pressure as found in Table VI is the difference be tween the first and second columns•
18 Table VII shows the arterial pressure rise due to the application of cold for the female subjects. is found the average arterial pressure.
In column one
This data was taken
from__theaverage arterial pressure as recorded in Table III. The second column in Table VII shows the rise in arterial pressure after the cold was applied to the hand.
is taken from the column ”Average Gelling” in Table V.
rise in pressure as found in Table VII is the difference between the first and second columns* Table VIII is a record of the effects of different agents on blood pressure when the cold pressor test is ap plied.
Each dot on the graph is a blood pressure recording.
There Is no definite interval of time between each recording. Table IX is the response of the systolic blood pressure to the cold test.
Each individual graph on this chart re
cords one individual's response to the cold test.
with hypertension gave the highest response while people with normal blood pressure gave* the least response to the cold test. The average increase in the systolic pressure due to the cold pressor test was 13.8 mm for the males and 11.2 mm for the females.
The increase In the diastolic pressure
was 9.35 mm for the males and 9.8 mm for the females. In view of the complexities surrounding so vast a study of hemodynamics as that which surrounds vasomotor
disturbances the results of this paper can. only be offered as a single isolated factor which may in time fit a pattern from which intelligent conclusions may be drawn*
is, therefore, submitted as a small record from which intel ligent conclusions may be drawn*
This work is, therefore,
submitted as a small record from which little more than the i status of a single phase of a huge problem is offered.
20 TABLE I ARTERIAL PRESSURE RISE DUE TO THE COLD PRESSOR TEST OF SEVEN INVESTIGATORS
Ayman and Gold shine (4)
Russek and Eohman (22)
Yates and Wood
Pickering and Kiss in (18)
CHAPTER V RECORD AND RESULTS OF EXPERIMENTS
TABLE II Arterial Pressure in the Supine Position MALES
23 TABLE III Arterial Pressure in the Supine Position FEMALES-
TABLE IV The Gold Pressor Test Arterial pressure after 30 and 60 second intervals with applied cold MALES Subject No*
25 TABLE V The Gold Pressor Test Arterial pressure after 30 and 60 second intervals with applied cold FEMALES
TABLE VI Arterial Pressure rise due to application of cold
Average Arterial Pressure
After Introduction of cold
Rise in Pressure
27 TABLE VII Arterial pressure rise due to application of cold FEMALES
Average Arterial “‘After Introduction Rise in Pressure of cold Pressure
2$ TABLE VIII THE EFFECT OF DIFFERENT AGENTS ON THE BLOOD PRESSURE RESPONSE TO THE COLD TEST
100 MO Hyptertension ino
t*s> After Hines and Brown
29 TABLE IX RESPONSE OF SYSTOLIC BLOOD PRESSURE TO THE COLD TEST
ArteriosclerosIs Hypertension Hypertension
After Hines and Brown
CHAPTER VI SUMMARY' 1. A simple, standard test to measure generalized vasomotor tonus has been devised in which ice water is used as a stimulus. 2. The mechanism producing the response is reflex in origin, bringing about a generalized vasoconstriction of the arterioles. 3. The cold pressor test is an index of vascular re activity.
There is a definite response in systolic and
diastolic blood pressures to local application of stimuli.
4* The average increase in the systolic pressure due to the cold pressor test was 13.$ mm for the males and 11.2 mm for the females.
The increase in the diastolic pressure
was 9*35 Bim for the males and females, 9-$ cm.
sults are well within the range of other investigators. 5. This investigation used 20 males and 10 females as subjects.
None of those used has case histories with assoc
iated hypertension. 6. Evidence points out from the literature that the res ponse to the cold pressor test is variable at different ages. There are so many intrinsic and extrinsic factors which may alter the reaction of the arterial system that this test may not be used with surety as a method of predicting hypertension.
32 BIBLIOGRAPHY 1.
Ayman, D. and Goldshine, A* D.: Cold as a Standard Stimulus of Blood Pressure; a Study of Normal and Hypertensive Subjects, New England I. Med. 219: 650, 1938.
Briggs, J. F. & Oerting, Harry: Vasomotor Response of Normal and Hypertensive Individuals to Thermal Sti mulus (Cold) Minnesota Med. 16: 481, ,1933.
Briggs, J. F.& Oerting, Harry: The Prognostic Value of the Cold Test in Pregnancy, Minnesota Med. 20: 382, 1937.
Chesley, L. G. and Chesley, E. R •: The Cold Pressor Test in Pregnancy, Surg. Gynec. & Obst. 39: 436, 1939.
Dieckmann, W.-J. and Michel,- H. L.: Thermal Study of Vasomotor Lability in Pregnancy; Preliminary Report, Arch. Int. Med. 55: 420, 1935.
Feldt, R. H., and Wenstrand, D. W.: The Cold-Pressor Test Subjects with Normal Blood Pressure; Am. Heart J. 23: 755, 1942.
Hines, E. A. Jr.: Reaction of the Blood Pressure of 400 School Children to a Standard Stimulus, J.A.M.A. 108: 1249, 1937.
Hines, E. A. Jr. and Brown, G. E.: Standard Stimulus for Measuring Vasomotor Reactions: Its Application in Study of Hypertension. Proc. Staff Meet. Mayo Clin. 7: 332, 1932.
Hines, E. A. Jr. end Brown, G. E.: Standard Test for Measuring Variability, of Blood Pressure: Its Signifi cance as Index of Pre-Hypertensive State, Aim. Int. Med. 7: 209, 1934.
Hines, E. A. Jr. and Brown, G. E.: Cold Pressor Test for Measuring Reactivity of Blood Pressure; Bata Con cerning 571 Normal and Hypertensive Subjects, Am. Heart J. 11: 1, 1936.
Hines, E. A. Jr.: Significance of Vascular Hyperreaction as Measured by Cold Pressor Test, Am. Heart J. 19: 408, 1940.
Hines, E. A* Jr. and Brown, G. E*: Arteriolar Hyper tonus Without High Blood Pressure (Latent Hyperten sion), Proc. Staff Meet. Mayo Clin. 11: 1, 1946.
Landis, 1. M., Brown, E. and Fauteux, M., and Wise, C.: Central Pressure in Relation to Cardiac "com petence* Blood Volume & Exercise.; J. Clin. Investi gation £5: 237-255, March 1946.
Jkevy, R. L. Mathers, A. L., Mueller, A. Jr.: Effects X'.of Smoking on Heart in Normal Persons & Cardiac / Patients. J.A.M. A. 135: 417-422, Oct. 1947.
Moia, B.: Present Value of Cold Pressor Test, Rev. Argent de Cardiol, 12: 106-112, May-June 1945.
Odell, L. D. & G. T. Aragon: " Cold Pressor Test & Kid ney Function, Am* J. Gbst. & Gynec. 54: 867-871, Nov. 1947.
Perteirra, I., Alimurung, M. M., and Nareiso, N #* Value of Cold Pressor Test in Hypertensive and Renal Diseases, Santo Tomas J. Med. 2: 300-204, July 1947.
Pickering, G. W. and Kissin, M.: The Effects of Ad renalin and of Cold on the Blood Pressure in Human Hypertension, Clin. Sc. 2:201, 1936.
Raab, W. P.: Hormonal Central and Renal Origin of "Essential" Hypertension (Cerebral and Renal Arter iosclerotic Ischemia as Causal Factors), Ann. Int. Med. 14: 1941.
Reider, N.: Blood Pressure Studies on Psychiatric Patients, Bull. Menninger Clin. 2: 65, 1938.
Reiser, M.;F. and Ferris, E. B.: Nature of the Cold Pressor Test and its Significance in Relation to Neurogenic and Humoral Mechanisms, J. Lab. & Clin. -Med. 32: 1480-1421, Nov. 1947.
Russek, H. I. and Burton, L. Zohman: Influence of Age Upon Blood Pressure Response to the Cold Pressor Test, Am. Heart Journal, 89, 113-119, 1945.
Russek, E. I.: The Significance of Vascular Hyperreaction as Measured by the Cold Pressor Test., Am. Heart J. 26: 398, 1943.
Schwab, E. H., Curb, B. L., Matthews, J. L. and Schulze, V. E.: Blood Pressure Response to a Standard Stimulus in the White and Negro Races, Proc. Soc. Exper. Biol, and Med. 32: 583, 1935.
Schwab, E. E. end Curb, D. L.: A Note on the Diagnosis of Hypertensive Cardiovascular Disease without Hyper tension, A«T. Lab. & Clin. Med. 24: 125, 1938.
Taquin, A. C.: Pressor Response to Cold or Racephedrine in Arterial Hypertension; Influencing Factors, Rev. Argent de Cardiol, 13: 309-317, Jan.-Feb. 1947.
Taquin, A. C. & Garcia Campo, M. E.: Value of Cold Pres sor Test in Evaluation of Variations of Arterial Pres sure, Rev. Argent de Cardiol, 12: 273-383, Nov.rDec. 1945. j Van Loon, J. A.: Cold Pressor Test in Ophthalmology, Ophthalmologies., 112: 63-71, Aug. 1946.
White, B. V. Jr. and Gildea, E. F.: ^Cold-Pressor Test* in Tension and Anxiety; Cardiographie Study, Arch. Neurol, and Psychiat* 38: 964, 1937.
Yates, M. R. and Wood, J. E. Jr.: Vasomotor Response of Non-Hypertensive Individuals to a Standard Cold Stimulus, Proc. Soc. Exper, Biol & Med. 34: 560, 1936.
Uataaraft? of ISoutltSffi California tJfeWW*