Zondek-Aschheim Reaction

ZONDEK-ASCHHEIM REACTION (W. Zondek, Aschheim), proposed in 1927, is a biological reaction for determining early pregnancy. Due to the simplicity of the method and almost error-free results, it has gained significant spread in a short time and is currently considered the only practically acceptable one. The idea of using urine to determine pregnancy arose long ago. In ancient times, among the Egyptians, many thousands of years before our era, there are numerous indications of such a possibility. The need for such a reaction is extremely necessary. The principle of the reaction is based on finding the hormone of the anterior pituitary gland in urine. The hormone of the anterior pituitary gland, prolan (it is also called gonadotropic hormone, i.e., having relation to the rudimentary glands), is not a product specific to pregnancy; it is found in the blood before, during and after puberty. The connection of the pituitary gland with the sexual apparatus has been known for a long time, as well as its change during pregnancy and during puberty. What is characteristic for pregnancy is the circumstance that several days after the cessation of the regular periods, the hormone of the anterior pituitary gland passes into the blood in significant quantities, and from the latter into the urine. Prolan in the urine of a pregnant woman, according to the authors' data, is determined on the 31st day after the beginning of the last menstruation. It is impossible to specify the exact day of appearance, since the time of implantation of the egg into the uterine mucosa is unknown. The test object for prolan is the ovary of an infantile white mouse, and the test reaction is multiple hemorrhages into the follicles (Blutpunkte) and the formation of lutein bodies. The hormone of the anterior pituitary gland, as is known, causes the follicular apparatus of the ovaries to come to life: the follicles begin to mature (I reaction), they fill with blood, hemorrhages visible to the naked eye or through a weak magnifying glass appear on the surface of the ovary (II reaction) and finally in the ovaries, as a result of excessive development of lutein tissue, yellow bodies are formed, mostly atretic (III reaction). For the diagnosis of pregnancy, the obtaining of II and III reactions is considered conclusive, i.e., the formation of hemorrhages (Blutpunkte) and yellow bodies. To perform the Z.-A. r., urine from a pregnant woman is required, preferably morning urine, since the hormone is in the highest concentration in it. In the laboratory, the urine is filtered, slightly acidified, and to every 25 cm³ a drop of pure tricresol is added. The experimental animals are infantile white mice weighing 6-8 g, not younger than three and not older than five weeks from birth. The mortality rate of mice in experiments reaches 15%, therefore at least five mice are required. In the experiment, one must take into account the possibility of the death of one or two animals, as well as the failure to obtain a reaction in one or another mouse. A positive result of the pregnancy reaction is considered the appearance in one mouse of at least one hemorrhage (Blutpunkt), one yellow body in the ovary of an infantile mouse. Each mouse receives six injections of urine in fractional doses (from 0.2 to 0.4) over 48 hours: 1st mouse 6x0.2=1.2; 2nd-6x0.25=1.5; 3rd-6x0.3=1.8; 4th-6x0.3=1.8 and 5th-6x0.4=2.4. On the first day of the experiment, 2 injections are made, on the second-3, on the third-one. After 96 hours from the first injection, the mice are killed by illuminating gas and dissected. In some cases, the answer can also be given after 60-72 hours. A positive response (result) of the Z.-A. r. is noted in 98.8%. The Z.-A. r. succeeds only in cases of "living" (non-interrupting) pregnancy. With the death of the egg or after the birth of the fetus (in the postpartum period), the hormone of the anterior pituitary gland is found for about 10 days, then it disappears and the reaction is negative. In addition to normal pregnancy, the Z.-A. r. has great diagnostic value in ectopic pregnancy (in the progressive form). A positive result indicates that the egg is still developing in the tube and the woman is on the verge of serious danger. In this case, the reaction serves as an important aid to diagnosis. The Z.-A. r. is used in hydatidiform mole and chorioepithelioma. In the first case, the pituitary hormone is found in large quantities and for a long period in the urine. Since in hydatidiform mole the embryo itself is often absent, the positive result of the reaction is due exclusively to the presence of chorionic elements in the maternal organism. As for chorioepithelioma, there are already a sufficient number of cases in the literature (F. Meyer, Rels, Ehrhardt) where a positive result with certainty revealed the presence of this malignant tumor. In addition to diagnostic value, this reaction in chorioepithelioma can serve as a reliable criterion for the success of the surgical operation performed. In cases of radical removal, the Z.-A. r. will be negative, while if there are metastases remaining in the patient's body, the reaction will be positive.