Chemistry of gonadotrophins in relation to their antigenic properties

Several chemical differences between FSH, LH and HCG have been reported: thus LH and HCG are richer in proline than FSH and FSH and HCG contain more N-acetyl neuraminic acid than LH.

Sub-units of LH are formed by treatment with urea, guanidine or acid. HCG also may contain two sub-units. The sub-units from LH are biologically inert but retain their immunological activity: biological activity is restored when the sub-units are incubated together.

There is much evidence from chemical and enzymic reactions that antigenic groups are distinct from those parts of the molecule essential for biological activity. N-acetyl neuraminic acid and probably other carbohydrates in FSH and HCG are not involved in immunological activity but are necessary for biological activity. Histidine, methionine and possibly cysteine appear to be essential for biological but not immunological activity of FSH, while tryptophan and possibly tyrosine are not essential for either.

A few highly specific antisera to gonadotrophins have been prepared in rabbits and guinea pigs to crude antigens: there is no evidence that purified antigens are more likely to produce specific antisera.

Differences in the immunological reactivities of urinary compared with pituitary gonadotrophins have been observed both by radioimmunoassay and by the complement fixation technique. The latter may be particularly useful for detecting structural differences in the hormones.

Neoplastic liability in Klinefelter's syndrome

One of the common clinical interests shared by physicians and psychiatrists is the genetically determined syndrome to which Klinefelter has given his name. Over the past few years positive identification has become possible through advances in cytogenetics, and more recently evidence has been accumulating which seems to indicate that a significant correlation may exist between Klinefelter's Syndrome and the development of other diseases, malignant disease in particular. Mental retardation is one of the most common symptoms found in the syndrome, so the psychiatrist is often in the best position to detect it. The case to be described here as well as having a few interesting facets of psychopathology may also provide more evidence of the pathological loading which the basic genetic abnormality seems to carry.

Joint action of gonadotrophic substances

Four experiments are described in which the joint action of certain pairs of six gonadotrophic preparations was studied. In every case similar joint action was demonstrated using the uterine weight in the immature mouse as the criterion of response.

These results are discussed with regard to the early action of gonadotrophins on the immature mouse ovary.