INHIBITION OF CORTICOSTEROID SECRETION BY AMPHENONE IN A PATIENT WITH ADRENOCORTICAL CARCINOMA*
GEORGE W. THORN, M.D.,t ALBERT E. RENOLD, M.D.,# ALAN GOLDFIEN, M.D.,§ DON H. NELSON, M.D., ”[ WILLIAM J. REDDY, A.B., || AND ROY HERTZ, M.D .**
BOSTON, MASSACHUSETTS, AND BETHESDA, MARYLAND
A MPHENONE was synthesized in 1950 by Allen and Corwin1 as one of a series of substituted desoxybenzoins and was selected by Hertz and his collaborators2,3 as a compound of potential biologic interest because of its structural relation to synthetic estrogens. These investigators found that the sub- stance exerted progestational activity in the rabbit, and a partly progestational, partly estrogenic activity in the rat. In addition, amphenone was shown to produce enlargement of both the adrenal and the thyroid glands. Later studies concerned primarily the nature of the adrenal enlargement and it was suggested that amphenone interfered with the pro- duction of active adrenocortical hormones, leading instead to the deposition of large amounts of inactive lipid material in the cells of the zona fasciculata and the zona reticularis of the adrenal cortex. In the hypophysectomized dog the intravenous administra- tion of amphenone led to the abrupt suppression of the secretion of 17-hydroxycorticoids after ACTH ad- ministration as measured by the corticoid content of adrenal-vein blood.3,4 When added in vitro to ad- renal slices, amphenone similarly inhibited the pro- duction of 17-hydroxycorticoids from suitable precur- sors.5 It was shown further that the process inter- fered with by amphenone is likely to be an ACTH- dependent one since the secondary adrenal enlarge- ment occurred only in the presence of ACTH. Simi- larly, the goitrogenic activity of the compound was pituitary dependent, whereas its effects on the female genital tract appeared to result from a direct action on the uterus and vagina.
Hertz and his collaborators6 administered amphe- none to patients with extensive metastatic breast can- cer to evaluate its effects on adrenal function. They observed an irregular decrease in adrenocortical secre- tion as measured by the excretion of 17-hydroxycorti- coids in the urine, but, with the dosage used, a con- stant suppression of 17-hydroxycorticoid secretion could not be achieved. The finding of marked adreno-
*From the departments of Medicine, Harvard Medical School and Peter Bent Brigham Hospital, the National Cancer Institute, National Institutes of Health and the Howard Hughes Medical Institute.
Supported in part by grants from the John A. Hartford Foundation, Incorporated, New York City; the National Institutes of Health, United States Public Health Service, Bethesda, Maryland; and the Eugene Hig- gins Trust and the Capps Fund of the Harvard Medical School.
+Hersey Professor of the Theory and Practice of Physic, Harvard Medical School; physician-in-chief, Peter Bent Brigham Hospital.
Instructor in medicine, Harvard Medical School; junior associate in medicine, Peter Bent Brigham Hospital.
§Research fellow in medicine, Harvard Medical School; assistant in medicine, Peter Bent Brigham Hospital.
[Research associate in medicine, Harvard Medical School; assistant in medicine, Peter Bent Brigham Hospital.
||Chemist, Peter Bent Brigham Hospital.
** Chief, Endocrinology Branch, National Cancer Institute, National Institutes of Health.
cortical hypertrophy at autopsy suggested that the failure to obtain complete suppression might have been due to excessive secondary compensatory secre- tion of ACTH. When amphenone was administered in large doses to man, a sedative action regularly occurred, and this made higher dosage impracticable.
It seemed reasonable to assume that amphenone administration would be most effective in the pres- ence of adrenocortical tissue not responsive to ACTH stimulation since a compensatory secretion of ACTH in that event would be without effect. Such a situa- tion might be postulated for adrenocortical carci- noma. Furthermore, the extraordinary histologic dis- tortion of adrenocortical cells produced by amphe- none suggested that the resulting gross intracellular lipid deposits might interfere with further tissue growth. Thus, when a patient with advanced meta- static adrenocortical carcinoma was admitted to the Peter Bent Brigham Hospital, the evaluation of the effects of amphenone seemed clearly indicated.
METHODS
The urinary levels of 17-hydroxycorticoids were determined by the method of Reddy,7 and the urinary 17-ketosteroids by a modification of the method of Drekter et al.8; urinary glucose excretion was meas- ured according to Froesch and Renold,9 with the use of glucose oxidase. Plasma levels of free 17-hydroxy- corticoids were determined by the technic of Nelson and Samuels,10 and those of conjugated 17-hydroxy- corticoids by that of Reddy et al.11
CASE REPORT
S.D. (P.B.B.H. 5H689), a 41-year-old housewife, was admitted to the Peter Bent Brigham Hospital on April 13, 1955, with the diagnosis of Cushing’s syndrome due to an adrenocortical carcinoma with metastases. She had been healthy and active until early in 1950, when she suffered partial loss of vision in the right eye. A diagnosis of retro- bulbar neuritis due to multiple sclerosis was made at that time. The eyesight gradually improved, and there were no further neurologic disturbances although a slight deepen- ing of the voice was noted - a symptom that did not pro- gress during the next 3 years. During the last 2 years be- fore admission, she noticed progressive hoarseness as well as very gradually increasing growth of hair on the chin, thinning of hair on the scalp and mild acne over the chest. During the last year there had been increased growth of pubic and axillary hair associated with some rounding of the face that became quite marked during the last 3 months. In November, 1954, the patient failed to menstruate (her menstrual history had been normal until that time) and began to gain weight rapidly; she gained 13.6 kg. (30 pounds) during the next 2 months. In December, 1954, she first noted swelling in the left supraclavicular area. During February, 1955, she began to note marked polyuria, poly-
dipsia and polyphagia. Although her appetite was good, she continued to feel weak, becoming increasingly fatigued, and a small abscess of the thigh developed that was drained surgically and healed. She went to Florida in March, but, feeling unwell, was seen by a physician, who found gly- cosuria and a fasting blood sugar of 300 mg. per 100 ml .; he suggested that she return to Massachusetts for treat- ment. She was admitted to her local hospital on April 2, when she was found to have diabetes, hypertension (a blood pressure of 190/100), limitation of diaphragmatic excursions on the left side and a left supraclavicular mass. A biopsy of the mass was carried out, and the histologic ap- pearance was compatible with the diagnosis of carcinoma of the adrenal cortex. She was given NPH insulin, 50 units daily, but was only poorly controlled on this regimen. During the last month before admission, she lost approxi- mately 11.3 kg. (25 pounds) in weight.
The past history was noncontributory, and there was no family history of diabetes, cancer or endocrinopathy.
ACTH ACTH
AMPH.
AMPHENONE
300-
URINARY
17-HYDROXY- CORTICOIDS mg./24 hr.
200
100
0
URINARY
300
17-KETO- STEROIDS mg./24 hr.
200
100-
ACTH (25 UNITS/8 HR.) AMPHENONE gm./24 hr.
0
4-
2.
OTHER TREATMENT WEEKS
4- TEPA-+
X-RAY
1 VIA 3 VIA 5 //A 7 VIII 9 VÀ
Physical examination disclosed a well developed, hoarse, middle-aged woman with a round, plethoric face and promi- nent eyes. She was perspiring freely. There was an in- crease of body hair and a decrease of scalp hair, with temporal thinning. There was a buffalo type of obesity, with only mild to moderate muscle wasting. The skin ap- peared and felt quite thin, although there were no striae. There were petechiae on the lower arms after the blood pressure had been taken. The blood pressure was 180/120. Mild acne was noted over the anterior aspect of the chest and upper quadrants of the abdomen. The thyroid gland was not palpable. There was a large, movable, hard, supraclavicular mass, 5 by 8 by 5 cm. The heart was es- sentially normal. Examination of the chest disclosed dull- ness, decreased breath sounds and fremitus at the left base posteriorly with fixation of the left hemidiaphragm. The abdomen was obese, soft and nontender, and there was some fullness in the left flank although no definite mass could be outlined. The liver edge was felt at the right costal margin. The spleen was not palpable. Pelvic exami- nation showed questionable enlargement of the uterus and of the clitoris. Neurologically, the examination was nega- tive.
Laboratory studies on entry showed the urine to be clear with a + test for protein, a ++++ test for sugar and a + + test for acetone. The hematocrit was 46 per cent, the white blood count 10,000 with 77 per cent neutrophils. Absolute eosinophil count on 2 occasions was 0. The platelets appeared to be normal. Blood urea nitrogen was 9 mg., and the serum protein 5.3 gm. per 100 ml. During the 1st 3 days after admission, the blood glucose values varied from 60 to 200 mg. per 100 ml. despite insulin therapy averaging 65 units a day. The serum bicarbonate was 26 millimols and the serum chloride 100 milliequiv., the sodium 140 milli- equiv., the potassium 3.8 milliequiv., and the calcium 5.3 milliequiv. per liter. The serum alkaline phosphatase was 2.8 Bodansky units, and the serum cholesterol 173 mg. per
100 ml. Liver-function studies were within normal limits. A stool was negative for occult blood. Uropepsin levels aver- aged 7500 units per 24 hours. The basal metabolic rate was +10 per cent. The protein-bound iodine was 1.8 microgm. per 100 ml., and the radioactive-iodine uptake 3 per cent in 24 hours. The plasma volume was 2390 ml., and the red-cell mass 1420 ml. An electroencephalogram was nor- mal.
X-ray examination of the heart and lungs revealed the left leaf of the diaphragm to be paralyzed although there was no definite evidence of pleural effusion. Skull films were normal. X-ray examination of the abdomen, includ- ing an intravenous pyelogram, showed displacement of the left kidney by an extrarenal mass in the region of the upper pole. In addition, slight to moderate hydronephrosis was present on the left side. The right kidney appeared normal. No erosion of the bones could be demonstrated, and there was but slight, generalized osteoporosis.
The urinary excretion of 17-hydroxycorticoids and 17- ketosteroids was measured daily and has been charted in Figure 1, together with the major items of the therapeutic regimen. This serves as an over-all illustration of the course during the 9 weeks in the hospital.
It is apparent that grossly abnormal quantities of both 17- hydroxycorticoids and 17-ketosteroids were excreted, the former measuring approximately 100 mg. (normal, 1 to 10 mg.), and the latter approximately 200 mg. per day (normal, 10 to 20 mg.). No increase in the excretion of either 17- hydroxycorticoids or 17-ketosteroids occurred during the intravenous administration of ACTH on 2 occasions, thus confirming the lack of ACTH responsiveness of the steroid- producing tissue. Figure 1 also shows that during the 1st half of the hospital stay a gradual increase in the daily amounts of excreted steroids occurred, a plateau being reached approximately during the 5th week. The abrupt changes in steroid excretion during the 2 periods of am- phenone administration are discussed below.
In addition to the 2 courses of amphenone, the thera- peutic agents used were thio-tri-ethylene-phosphor-amide (TEPA) and local irradiation. A total of 120 mg. of TEPA was given over a period of 12 days. This did not produce any striking clinical change other than a possible softening of the supraclavicular mass. On the other hand, the maxi- mal dose of TEPA likely to be tolerated was reached since a marked depression of all formed blood elements occurred and persisted for some 2 weeks after the end of the ad- ministration of the compound, with subsequent gradual return to normal levels. Local irradiation to the left flank was administered because of increasing pain and without definite evidence of effectiveness.
The clinical course in general was marked by progressive deterioration, by increasing pain in the region of the left costovertebral angle and flank, radiating along the costal margin and to the left shoulder, and by repeated left-sided pleural effusions yielding bloody fluid that contained many tumor cells. In addition, progressive deterioration of the psychologic situation occurred, with episodes of acute anx- iety, at times correlated with difficulty in breathing. Dur- ing the 10th hospital week, a biopsy of the supraclavicular mass was to be performed. On the way to the operating room the patient became acutely dyspneic and cyanotic, and, although an intratracheal tube was inserted immediate- ly and artificial respiration applied, cardiac arrest occurred within 1 hour. At post-mortem examination, the terminal episode was shown to have resulted from massive pulmonary embolism. Further findings included an orange-sized tumor of the left adrenal gland and many lymphatic metastases along the left retroperitoneal and retropleural space, with invasion of the diaphragm and of the left pleura and with further metastatic involvement of the left supraclavicular and axillary lymph nodes. Profuse hematogenous spread, with many hepatic and bony metastases, had occurred. The contralateral adrenal gland was atrophic. The pituitary gland was grossly normal.
Results of Amphenone Administration
Amphenone B was administered in two courses. The first course lasted for two days. An initial dose
of 1.0 gm. was given by mouth, followed by 500 mg. every three hours throughout the first day. On the second day, the dose was increased to 500 mg. every two hours. As shown in Figure 2, the urinary 17-hy- droxycorticoids were measured in each six-hour por- tion of urine, and a great decrease in their excre- tion was apparent from the twelfth hour onward. Throughout the second day the rate of 17-hydroxy- corticoid excretion was less than a fifth of that on the control day. After discontinuation of the drug, the pretreatment level was reached within twenty-four hours. A further dramatic change during amphenone therapy concerned the severity of the glycosuria and the insulin requirement. Urinary glucose excretion dropped from approximately 40 gm. daily to some- what over 20 gm. on the first and to 2.5 gm. on the second day of amphenone administration, with an immediate increase to pretreatment levels after dis- continuation of the drug. The changes in blood glu- cose levels concurred. The significance of these glu- cose changes was enhanced by the simultaneous de- crease in the dose of insulin administered, the total daily dose dropping from 74 units on the day before treatment to 13 units on the first day and to 0 on the second day of amphenone therapy. Insulin was also withheld during the first day after treatment. It should be added that food intake during the first day of amphenone therapy was not essentially differ- ent from that during the days before therapy but that some anorexia was present on the second day. As previously demonstrated in Figure 1, the changes in the urinary excretion of 17-ketosteroids were much less striking than those previously described for the 17-hydroxycorticoids.
Whereas no significant side effects of the therapy were noted during the first day of amphenone admin- istration, moderate anorexia set in during the second day and was followed by subjective feelings of anguish and agitation. Toward the end of the second day, the patient became acutely uncomfortable, complain- ing of profuse sweating, prostration and depression. On physical examination, she was found to be cool and clammy, with evidence of peripheral vasoconstric- tion, and her blood pressure was 120 systolic, 80 diastolic, as compared with a previous level of 180 systolic, 110 diastolic. Administration of the drug was discontinued, and gradual improvement was seen during the next twelve hours. Although a direct toxic effect of amphenone could not be excluded, this epi- sode was interpreted in retrospect as being suggestive of the syndrome observed after acute steroid with- drawal.
From this first trial of amphenone it was concluded that a considerable effect on the adrenal secretion of 17-hydroxycorticoids had been obtained, as evidenced not only by the decreased urinary steroid excretion but also by the spectacular improvement of the dis- turbance in carbohydrate metabolism. It was be- lieved, however, that a more gradual reduction in the
steroid secretion would be preferable, and that it might be necessary to supplement the too rapidly de- creasing endogenous steroid production by the ad- ministration of decreasing doses of exogenous hor- mone.
Throughout the second course of amphenone therapy, which lasted for five days, 250 mg. of the compound was administered by mouth every two hours during the day and 500 mg. every four hours during the night. Although a more gradual fall in
80-
URINARY 17-HYDROXY- CORTICOIDS mg./6 hr.
40-
0-
74
76
INSULIN units/24 hr.
50
13
FASTING BLOOD SUGAR mg./100 ml.
0
0
0
228
238
125
132
189
URINARY GLUCOSE gm./24 hr.
40-
20-
0-
AMPHENONE gm./24 hr.
4.
DAYS
0
1
2
3
4
5
urinary 17-hydroxycorticoid excretion was achieved, the patient began to complain of weakness and sweat- ing from the third day onward, and it was considered advisable to administer 8 mg. of fluorohydrocortisone (approximately equivalent to 160 mg. of cortisone) on the third day and 4 to 6 mg. on the following days. On the fifth day of amphenone administration, and despite the concurrent administration of fluorohydro- cortisone, she again complained of profuse sweating, prostration and abdominal distention; her skin was cool and clammy, and the blood pressure dropped to 100 systolic, 60 diastolic. In addition, she went through an episode of psychotic behavior with so- matic hallucinations and acute anxiety, the latter sufficiently severe to indicate the intravenous admin- istration of amobarbital sodium (Amytal) for relief. At that time the serum potassium was 3.3 milliequiv. and the serum sodium 126 milliequiv. per liter. X-ray examination of the abdomen showed a dis- tended, air-filled stomach. Amphenone administra- tion was discontinued, a Levin tube was inserted, and the intravenous infusion of 40 milliequiv. of potas- sium chloride in 1 liter of saline solution was started; rapid improvement ensued. Fluorohydrocortisone was continued for three days after discontinuation of amphenone therapy.
Again, the effects of amphenone on the urinary excretion of 17-hydroxycorticoids were striking (Fig. 3), the twenty-four-hour excretion dropping from 260 mg. to an average of 50 mg. per day during the last three days of therapy. Plasma 17-hydroxycorticoid levels showed a remarkable drop of both the free and the conjugated fractions during the period of amphe-
600-
PLASMA
·-· FREE
17-HYDROXY- CORTICOIDS microgm./ 100 ml.
400-
4 --- & CONJUGATED
200-
1
0
URINARY
200
17-HYDROXY- CORTICOIDS mg./24 hr.
100-
AMPHENONE gm.
0
2.0-
FLUORO-F
0
mg./24 hr.
5
DAYS
0
I VIA 3 V/ 5 V/A 7 VZA 9 VIA WZ
none administration. It should further be pointed out that the urinary excretion of 17-hydroxycorticoids rose from 50 mg. on the last day of amphenone treatment to 197 mg. on the third day after discontinuation of therapy even though the patient was at that time maintained on 6 mg. of fluorohydrocortisone daily. This adds further evidence for the lack of dependence on ACTH of the steroid-producing tissue, since 6 mg. of fluorohydrocortisone daily is sufficient to suppress 17-hydroxycorticoid secretion by the normal adrenal glands.12,13
An attempt was made to keep the patient on a con- stant dietary regimen throughout this second period of amphenone administration. Although a truly con- stant regimen could not be maintained, the results of the metabolic studies performed (Fig. 4) demon- strated that marked sodium retention was present throughout and that the urinary excretion of potas- sium decreased during amphenone therapy with a re- bound after withdrawal of the drug and hence on the day when adrenal secretion of glucocorticoids re- turned. The urinary excretion of glucose, nitrogen and phosphate similarly decreased during amphenone therapy and despite the concurrent administration of fluorohydrocortisone.
In addition to the studies mentioned, the follow- ing parameters were checked every second day before, during and after amphenone administration: hemato- crit, leukocytes, thrombocytes, serum protein, choles- terol, calcium, phosphate, bilirubin, thymol turbidity and endogenous creatinine clearance. No significant changes could be detected. Adequate studies of
changes in thyroid function could not be made since values for protein-bound iodine and I131 uptake were vitiated by the recent administration of iodine-con- taining dye.
DISCUSSION
From the studies that have been presented it ap- pears that the secretion of adrenal corticoids by a metastasizing adrenocortical carcinoma was marked- ly inhibited by the oral administration of amphenone B in amounts of 3 to 5 gm. daily in divided doses. This conclusion seems justified since it is based on
INTAKE:
SODIUM POTASSIUM CALORIES CARBOHYDRATES PROTEIN
51
51
50
49
47
46
47
50
38
83
83
82
75
78
76
75
121
52
2112
2112
2086
1903
1800
1769
1838
1978
1209
199
199
199
199
159
147
165
183
96
104
104
102
90
93
86
92
100
69
URINARY
SODIUM
10-
milliequiv./ 24 hr.
URINARY POTASSIUM milliequiv./ 24 hr.
50
97
URINARY GLUCOSE gm./24 hr.
40-
20-
URINARY NITROGEN gm./24 hr.
10-
URINARY PHOSPHATE mg./24 hr.
500
URINARY CREATININE mg./24 hr.
1000
AMPHENONE
gm./24 hr.
2
.
INSULIN units/24 hr.
50-
FLUORO-F mg./24 hr.
5
DAYS
measurements of both urinary and plasma 17-hy- droxycorticoids as well as on changes in the meta- bolic effects of the secreted hormone. The urinary metabolites of amphenone do not interfere with the colorimetric methods employed. A clear-cut action of amphenone in man has thus been established, at least for adrenocortical tissue lacking its normal de- pendence on ACTH. This lack of ACTH dependence was inferred from the absence of any demonstrable response on the part of the tumor tissue when stimu- lated with intravenously administered ACTH, as well as from the rapid increase in corticoid excretion after
amphenone withdrawal even though ACTH-suppress- ing doses of fluorohydrocortisone were being admin- istered at that time.
Whereas the effects of amphenone on the adrenal secretion of carbohydrate-active steroids were pro- found and immediate, as measured both by the changes in 17-hydroxycorticoid levels in blood and urine and by the alteration in the severity of the dia- betes, the effects on the urinary excretion of 17- ketosteroids were relatively slow and unimpressive. Indeed, the changes in 17-ketosteroid excretion that did occur could well have represented mainly a de- creased catabolismof 17-hydroxycorticoids to 17- ketosteroids. More recent findings, however, have shown that amphenone metabolites in the urine may interfere with the Zimmerman color reaction used for the determination of urinary 17-ketosteroids. When chromatographic technics were employed definite sup- pression of 17-ketosteroid excretion during the period of amphenone B administration became apparent.
Toxic effects of amphenone on bone marrow, red blood cells, liver or kidney were looked for, but none were found. Twice, however, when striking depres- sion of steroid secretion was achieved, a syndrome de- veloped that included sweating, prostration, hypo- tension and anorexia. This clinical picture appeared classic for acute adrenocortical insufficiency as seen in patients maintained on high-steroid doses after abrupt cessation of the hormone therapy. It is further of interest that during the second of these episodes severe hyponatremia occurred despite continued marked positive sodium balance, a finding highly sug- gestive of a sudden rearrangement of total body sodium distribution. This observation is in agreement with the normal sodium value found in a patient with previously undiagnosed Addison’s disease admitted to a hospital in classic and severe crisis.14
The duration of amphenone administration was too short to permit even a preliminary evaluation of the possible effect of the drug on tumor growth.
SUMMARY AND CONCLUSIONS
A case of Cushing’s syndrome due to a metasta- sizing carcinoma of the adrenal cortex secreting large amounts of adrenocortical steroids is presented. The tumor tissue lacked the responsiveness to ACTH stimulation characteristic of normal adrenocortical tissue. The administration of amphenone B to this patient resulted in a decreased secretion of carbo- hydrate-active corticoids, as evidenced by the changes in the levels of 17-hydroxycorticoids in plasma and in urine as well as in the biologic effects of these steroid hormones.
The available evidence indicates that amphenone B specifically interferes with the synthesis in adreno- cortical tissue of biologically active 17-hydroxycorti- coids from inactive precursors. A similar interference with the synthesis of potentially androgenic 17-keto- steroids has not yet been demonstrated.
REFERENCES
1. Allen, M. J., and Corwin, A. H. Electrolytic reduction of p- aminoacetophenone. J. Am. Chem. Soc. 72:114-117, 1950.
2. Hertz, R., Allen, M. J., and Tullner, W. W. Effects of amphe- none “B” on thyroid, adrenals and genital tract of female rat. Proc. Soc. Exper. Biol. & Med. 75:627-630, 1950.
3. Hertz, R., Tullner, W. W., Schricker, J. A., Dhyse, F. G., and Hallman, L. F. Studies on amphenone and related compounds. Recent Progr. in Hormone Research 11:119-147, 1955.
4. Nelson, D. H. In discussion of Hertz et al.3
5. Dorfman, R. I. Cited by Hertz et al.3
6. Hertz, R., Pittman, J., and Graff, M. Unpublished data.
7. Reddy, W. J. Modification of Reddy-Jenkins-Thorn method for estimation of 17-hydroxycorticoids in urine. Metabolism 3:489-492, 1954.
8. Drekter, I. J., et al. Determination of urinary steroids. I. Prep- aration of pigment-free extracts and simplified procedure for es- timation of total 17-ketosteroids. J. Clin. Endocrinol. 12:55-65, 1952.
9. Froesch, E. R., and Renold, A. E. Specific enzymatic determina- tion of glucose in blood and urine using glucose oxidase. Diabetes (in press).
10. Nelson, D. H., and Samuels, L. T. Method for determination of 17-hydroxycorticosteroids in blood: 17-hydroxycorticosterone in pe- ripheral circulation. J. Clin. Endocrinol. 12:519-526, 1952.
11. Reddy, W. J., Abu Haydar, N., Laidlaw, J. C., Renold, A. E., and Thorn, G. W. Determination of total 17-hydroxycorticoids in plasma. J. Clin. Endocrinol. (in press).
12. Goldfien, A., Laidlaw, J. C., Abu Haydar, N., Renold, A. E., and Thorn, G. W. Fluorohydrocortisone and chlorohydrocortisone, highly potent derivatives of Compound F. New Eng. ]. Med. 252: 415-421, 1955.
13. Renold, A. E., Abu Haydar, N., Reddy, W. J., Goldfien, A., and St. Marc, J. R. Biological effects of fluorinated derivatives of hydrocortisone and progesterone in man. Ann. New York Acad. Sc. 61:576-584, 1955.
14. Arons, W. L., Nusimovich, B., and Vanderlinde, R. L. Exchange- able body sodium and potassium measurements in hyper- and hypo- adrenocorticism. J. Clin. Endocrinol. 15:584, 1955.