SUMMARY The daily urinary excretion of luteinizing hormone (LH) was determined in 15 boys, aged 5–11 yr., and in 15 adult men, aged 18–65 yr., by an immunological method using the haemagglutination inhibition system. The hormone was detected in every subject investigated. The mean value for urinary LH excretion in boys was equivalent to 3·4 i.u./24 hr. (range 1·3–6·5) and was 29·3 i.u./24 hr. in adults (range 15·4–44·6). The mean adult: child ratio was 8·6. There was a significant increase in LH output with age in both the boys and the men; the rate of this increase was the same in both groups. However, there was a sharp rise in hormone output at about the onset of puberty.

The concentration of human chorionic gonadotrophin in fluid content from differently-sized groups of hydatid vesicles, serum and urine was determined in five patients with hydatidiform mole by an immunological method. The HCG concentration of fluid content from small hydatid vesicles (0.3-0-7 cm. in diameter) was significantly higher than that of fluid content from large hydatid vesicles (0.8-1.2 cm.). The HCG value of serum was always much lower than that of fluid content from both small and large hydatid vesicles. The vesicle/serum ratio of HCG concentration ranged from about 1 . 5 to 4.5. The urinary level of the hormone was higher than that of both serum and vesicular fluid, except in one case. The results have been related to the different hypotheses of the pathogenesis of hydatidiform mole. The results seem to support Hertig's hypothesis which considered (1) the trophoblastic hyperplasia to be a result of the enlargement of the villusvesicle and (2) the hydatid fluid to be a product of the active trophoblastic tissue of the mole.

Summary The 24‐hour urinary excretion of luteinizing hormone (LH) was determinded in 24 girls, aged 4 to 11 years, and in 15 normal menstruating women, aged 18 to 44 years, by an immunological method using the haemagglutination inhibition reaction after a tannic acid extraction. LH was detected in every subject investigated. The mean value for urinary LH excretion in girls was equivalent to 3.8 i.u. (2nd IRP‐HMG) per 24 hours (range 1.2–8.0) and was 29.8 i.u. per 24 hours (range 24.0 to 38.0) in adult women. In girls the LH output increased significantly with age. In normally menstruating adult women, the LH output increased slightly but not significantly with age.

Few and conflicting reports have so far been published on the urinary excretion of luteinizing hormone (LH) in childhood (for reference, see Leone & Sciarra (1966 a) and Rifkind, Kulin & Ross (1967). Further investigation seemed therefore indicated.The daily excretion of LH was determined semiquantitatively in 24 normal, healthy and non-hospitalized prepubertal children (12 boys and 12 girls), aged 5\p=n-\10 yr. A complete 48 hr. urine specimen (1000\p=n-\2000 ml.) was collected from every subject without the use of a preservative and stored in a cold room at 4\ s=deg\ .Within 3 days of the urine collection, each sample was extracted by Johnsen's tannic acid method (1958) but using, as a rule, the highest concentrations of reagents suggested by the Danish author. Twenty-four hours before assay, the dry precipitates were ground to fine powder and redissolved in a 0\m=.\9% NaCl solution. As described by Sciarra, Pastorino & Leone (1968) the powders proved so soluble that they could be dissolved in very small amounts of saline 0\m=.\5\p=n-\ml.); consequently, urinary LH was concentrated up to 1000-4000 times with a 67 + 5 % recovery rate. After centrifugation, the supernatants were serially diluted with intervals of 1:1-5. LH was assayed by the immunological method of Wide & Gemzell (1962) but using the reagents of the Pregnosticon Test (Organon), the sensitivity of which was previously established at 1-6 i.u. LH (2nd IRP-HMG)/ml. (Leone & Sciarra, 1966&). The excre¬ tion results were corrected for the 33 % mean methodological loss by tannic acid extraction.In order to evaluate the results, reliability criteria for the method and regression of LH excretion on age for both males and females, with 95 % confidence limits, were calculated. Tests for deviation from parallelism were carried out. The accuracy of the method was in the region of 100 % ; its precision was high (mean = 0-12, range 0-08 to 0-15); its sensitivity was in the range of 0-6-1-2 i.u. LH/24 hr. urine vol. With regard to specificity, the test failed with several urinary extracts from two hypophysectomized young women; virtually no LH activity could be detected in the same extracts by the ventral prostate weight method as modified by McArthur (1952). However, the results were positive in pregnant women. Figure 1 shows that LH was detected in all the children investigated ; the mean urinary hormone level in boys was 2-9/i.u. LH/24 hr. (range 1-2-5-4) and 2-8 i.u./ 24 hr. in girls (range 0-6-5-4); it increased with age in both sexes and more rapidly in females than in males.These results, together with the observations of previous workers who demon-