SummaryAlcohol prolan shows the electrokinetic behavior of a single chemical individual. The isoelectric point is more acid than pH 3.5. Brucine prolan behaves as a mixture. The physiological activity of prolan is attributed to a grouping which may survive chemical treatment drastic enough to alter the protein-like carrier.

M O OST recent studies concerned with the pituitary secretions have revealed increasingly frequent reference to the factor of species variation in the elucidation of certain of the data. In i9Z9 Houssay found that pituitary implants from different vertebrate classes could not duplicate the phenomenon of ovulation induction as it was produced in the toad by homoplastic implants. He was probably the first to advance the hypothesis of gonadotropic hormone species specificity as a basis for the interpretation of these results. Since that time it has become definitely established that there is a variation in qlaantity of the anterior pituitary hormones from species to species. This fact has been sufficient to explain many cases of apparent irregularities in response, or in dosage required to produce a given response. In some cases, however, and especially those cases in which the hormone donor and recipient are of widely divergent taxonomic types, it becomes clear that a qualitative variation in the hormones, like that postulated by Houssay, must be given consideration. Such a conception represents an advance over the general opinion held by endocrinologists a few years ago as summarized by P. E. Smith (I932) "A species specificity either in a hormone or in the receptivity to a hormone is contrary to the current concept of hormonal physiology." Since i9Z9 numerous instances of refractoriness of animals to pituitary hormones of extra-specific origin have been presented in the literature of endocrinology, and these have been explained in various ways. The possibility of hormone species specificity has often been proposed, but almost never systematically tested. In I935 Creaser and Gorbman (I935, I936) examined the refractoriness of the common leopard frog, Rana pipiens, to large doses of mammalian gonadotropic materials, in contrast to its ready response to homoplastic treatment or treatment with pituitaries from closely related species. They concluded after elimination of all factors, excepting those characteristic and common to the number of actual hormone mixtures tested, that a gonadotropic hormone species specificity has been demonstrated. The discovery of antihormones by Collip and Anderson (I934) directed considerable attention to the question of pituitary hormone species specificity inasmuch as a number of investigators have claimed that antihormones are merely antibodies formed in response to immunologically distinct, and therefore species specific, hormones. The implication of hormone specificity in cases of chronic injection of anterior

Electrophoresis of Prolan.

Species Specificity of the Gonadotropic Factors in Vertebrates

Publisher Summary This chapter discusses the chemistry of four gonadotropic hormones ICSH, FSH, PMSG, and HCG. These hormones have been prepared in different degrees of purity; HCG has been prepared in crystalline form. Purest of all is the ICSH isolated from sheep and pig glands; its homogeneity has been established by the solubility test which is the most reliable criterion of purity for a protein. These gonadotropic hormones are glycoproteins; in addition to the amino acid constituents, these substances contain hexose and hexosamine. Destruction of the carbohydrate residue by enzymes causes inactivation of the hormones. Similarly, modification of protein groups decreases the gonadotropic activity. Both the carbohydrate and protein parts are essential for the biological action. There are no indications of the occurrence of prosthetic groups in these hormones. The availability of pituitary glands has limited the practical applications of FSH and ICSH in human therapy. In addition, there is evidence for the formation of antihormone during the administration of these gonadotropins. This may be avoided by the use of hormone preparations isolated from human tissues or fluids.

The Chemistry of Gonadotropic Hormones

Über die gonadotropen Hormone

False negative reactions in pregnancy testing with frogs and toads can be avoided by concentrating the urinary chorionic gonadotrophin. If unconcentrated urines are used, the incidence of these reactions may be as high as 43.7 per cent' and 50 per cent.8 Inaccuracy occurs most frequently during the late summer and early autumn months when many batrachians are relatively insensitive, and also when urinary chorionic gonadotrophin titers are low, in very early pregnancies, and in the latter half of gestation. To be useful, a concentration technique must be simple to perform and provide adequate recovery of the hormone. Furthermore, the final concentration product must be non-toxic and must not produce false positive reactions.

Electrophoresis of Prolan.

Citations

Species Specificity of the Gonadotropic Factors in Vertebrates

The Chemistry of Gonadotropic Hormones

Über die gonadotropen Hormone

A rapid technique for concentration of urinary chorionic gonadotrophin for pregnancy testing.

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