Ray Peat - Letter to the Editor - Oral Absorption of Progesterone
2
LETTERS TO THE EDITOR UNDERREPRESENTATION IN GRADUATE MEDICAL EDUCATION AND MEDICAL RESEARCH To the Editor: I am a student who entered How- ard University last fall to major in zoology and to further pursue a career in research. In reading an article in the journal (J Natl Med Assoc 1984; 9:857-862) entitled "The Underrepresented in Gradu- ate Medical Education and Medical Research," I was thoroughly engrossed by what Dr. Pinn had written, and I felt strongly that I had to respond because of my in- terest in science. Yes, I strongly feel that the aca- demic role model of women should be increased through programs that will show their participation and visibility in the medical world. Yes, I strongly feel that minorities should be aware of the other aspects of medicine. This summer, I had the opportunity to meet several doctors and to see the different areas involved with medicine as a research apprentice at Children's Hospital. Too many times, when young people who have expressed an interest in medicine are asked what area they would like to specialize in, the an- swer is pediatrics. Pediatrics is fine, but what about virology, en- docrinology, and nephrology? And yes, what about research? As an individual, I know that my inquisitiveness has helped me to become involved in many new experiences that I would not otherwise have known about. Yet in order for us, as youngsters, to learn about other areas of medi- cine, doctors in the community need to guide us as role models and help us gain the experience needed. Sheila Mathias Columbia, Maryland ORAL ABSORPTION OF PROGESTERONE To the Editor: Since many synthetic progestins are known to be luteolytic,' and while progesterone itself exerts a positive feedback influence on steroidogenic tissue,2 it is clear that it would be useful to have an effec- tive way to administer proges- terone orally. It is well known that fat-soluble substances are absorbed primarily by way of the lymphatic system, entering the general circulation di- rectly rather than passing first through the liver.3 Progesterone is insoluble in water, but it is soluble in lipids. If the solution is stable, it seems clear that the progesterone will be preferentially absorbed by the lymphatic route. I have investigated the oral use of progesterone in tocopherol, a nontoxic stable solvent, in cycling women with a luteal phase defi- ciency and in postmenopausal women. In younger women, who are still producing large amounts of estro- gen, a therapeutic effective oral dose (50 to 200 mg daily during the luteal phase of their cycles) was found to prevent the symptoms associated with premenstrual de- crease in serum progesterone ob- Continued on page 185 182 JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 78, NO. 3, 1986
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Transcript of Ray Peat - Letter to the Editor - Oral Absorption of Progesterone
LETTERS TOTHE EDITOR
UNDERREPRESENTATIONIN GRADUATE MEDICALEDUCATION AND MEDICALRESEARCH
To the Editor:I am a student who entered How-
ard University last fall to major inzoology and to further pursue acareer in research. In readingan article in the journal (J Natl MedAssoc 1984; 9:857-862) entitled"The Underrepresented in Gradu-ate Medical Education and MedicalResearch," I was thoroughlyengrossed by what Dr. Pinn hadwritten, and I felt strongly that Ihad to respond because of my in-terest in science.
Yes, I strongly feel that the aca-demic role model of women shouldbe increased through programs thatwill show their participation andvisibility in the medical world.
Yes, I strongly feel thatminorities should be aware of theother aspects of medicine. Thissummer, I had the opportunity tomeet several doctors and to see thedifferent areas involved withmedicine as a research apprentice
at Children's Hospital. Too manytimes, when young people whohave expressed an interest inmedicine are asked what area theywould like to specialize in, the an-swer is pediatrics. Pediatrics isfine, but what about virology, en-docrinology, and nephrology? Andyes, what about research?
As an individual, I know that myinquisitiveness has helped me tobecome involved in many newexperiences that I would nototherwise have known about. Yetin order for us, as youngsters, tolearn about other areas of medi-cine, doctors in the communityneed to guide us as role models andhelp us gain the experience needed.
Sheila MathiasColumbia, Maryland
ORAL ABSORPTION OFPROGESTERONETo the Editor:
Since many synthetic progestinsare known to be luteolytic,' andwhile progesterone itself exerts a
positive feedback influence onsteroidogenic tissue,2 it is clear thatit would be useful to have an effec-tive way to administer proges-terone orally.
It is well known that fat-solublesubstances are absorbed primarilyby way of the lymphatic system,entering the general circulation di-rectly rather than passing firstthrough the liver.3 Progesterone isinsoluble in water, but it is solublein lipids. If the solution is stable, itseems clear that the progesteronewill be preferentially absorbed bythe lymphatic route.
I have investigated the oral useof progesterone in tocopherol, anontoxic stable solvent, in cyclingwomen with a luteal phase defi-ciency and in postmenopausalwomen.
In younger women, who are stillproducing large amounts of estro-gen, a therapeutic effective oraldose (50 to 200 mg daily during theluteal phase of their cycles) wasfound to prevent the symptomsassociated with premenstrual de-crease in serum progesterone ob-Continued on page 185
182 JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 78, NO. 3, 1986
LETTERS TO THE EDITOR
Continued from page 182
served in previous cycles, but insome women the effective dosecaused the blood levels to risesomewhat above the levels usuallyconsidered normal for the lutealphase.
Postmenopausal women, whohave much lower average levels ofestrogen and who produce littleprogesterone, show much moreclearly the effects of administeredprogesterone. Seven women whohad gone through "natural" meno-pause at least two years previously,and whose serum progesterone waseither below the sensitivity limit ofthe competitive protein-bindingtechnique or in the typically lowpostmenopausal range of meas-urement by radioimmunoassay,were given oral doses of 50 or 100mg of progesterone in tocopherol.
The earliest any blood wasdrawn after an oral dose ofprogesterone was 20 minutes; inthis case, the progesterone hadrisen from 0.2 ng/mL before to 0.7ng/mL after a dose of 100 mg.When blood was drawn from fourto eight hours after an oral dose of50 to 100 mg, the blood levels werebetween 6 and 16 ng/mL. No at-tempt was made to assure that theprogesterone was taken on anempty stomach; meals were eatenas usual while waiting for blood tobe drawn. The progesterone wasadministered by the women's phy-sicians, and the measurement wasdone by commercial medical lab-oratories.
In two cases in which blood wasdrawn 24 hours after a single doseof 100 mg, the progesterone levelwas still in the normal luteal phaserange.
Since the observations weremade over a period of several
years, with progesterone meas-urements made at several differentlaboratories by different tech-niques, the numbers are not strictlycomparable. We recently got aclearer picture of the rate of ab-sorption in a fasting person. Amiddle-aged man, with a fastinglevel of 0.2 took 100 mg. At the firsthour, the progesterone level wasalready 7.0 ng/mL; the concentra-tion rose each hour to a peak at thesixth hour of 14.0 ng/mL, and thelast measurement, at the seventhhour, was 7.0 ng/mL. On average,men's livers are quicker to removesubstances from the blood, and thefact that no food was taken duringthe test very likely caused the rateof increase and the rate of decreaseto be greater than in a nonfastingperson.
In summary, when dissolved intocopherol, progesterone is orallyactive. A single oral dose of 50 to200 mg given to women with lutealphase insufficiency or to post-menopausal women brings theirblood progesterone levels up to atleast the normal luteal phase rangeand maintains it in that range for atleast 12 hours.
Raymond Peat, PhDEugene, Oregon
Literature Cited1. Badawy SZA, Marshall L. Luteal
phase inadequacy and infertility. FamPract News 1981; 6:17A-24A.
2. Rothchild I. The regulation of themammalian corpus luteum. Recent ProgHorm Res 1981; 37:183-298.
3. Simmonds WJ. Absorption of lipids.In: Jacobson ED, ed. GastrointestinalPhysiology. Baltimore: Butterworths,University Park Press, 1974, p 343.
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