Confronted with these unexpected data, scientists started looking for a plausible theory to explain the source and identity of these “heterosexual hormones” (as female sex hormones in male organisms, and vice versa, were named) (Jongh 1934b: 1,209). In the 1930s, different hypotheses were proposed to explain the presence of female sex hormones in male organisms. In some of these hypotheses, scientists tried hard to maintain the dualistic conceptualization of sex according to which male and female were denned as mutually exclusive categories.
In 1929, Robert Frank suggested that female sex hormones were not produced by the male body itself, but that they originated from food (Frank 1929:293). In the late 1930s, this hypothesis was criticized as implausible by, among others, the Amsterdam School (Dingemanse et al. 1937). Despite this criticism, the food hypothesis remained popular. In Sex and Internal Secretions, the food hypothesis is advanced without paying attention to the critical notes of the author of the cited paper:
Following the demonstration of the wide occurrence of estrogens in foods, it became apparent that estrogens in male urine need not necessarily imply their secretion in the male body. Eng (1934) reported that when a young man was placed on an estrogen-free diet, the excretion of estrogen in both urine and faeces dropped to 3 mouse units per day. On a standard diet, between 13 and 44 units per day could be recovered from the urine of the same man.
(Allen et al. 1939:561)
The food hypothesis seems to have been postulated only for the presence of female sex hormone in male organisms: no reports were published attempting to explain the presence of male sex hormones in females by the intake of male hormones from food.
In contrast with Frank, British scientists like the biologists Nancy and Robert Callow and Alan Parkes from the National Institute for Medical Research in Hampstead, London, suggested that male bodies should be considered capable of producing female sex hormones and proposed the adrenals as one of the sites of the production of sex hormones. (Callow and Callow 1938; Parkes 1937). The adrenal hypothesis was still consistent with the prescientific idea of a sexual duality, in which it was impossible to consider the gonads capable of excretion of both sex hormones. In 1951,
Samuel de Jongh, one of the laboratory scientists of the Amsterdam School, evaluated the proposal of the adrenal hypothesis as follows:
By proposing the hypothesis of an extra-gonadal source to explain the presence of female sex hormones in male bodies, scientists could avoid the necessity to attribute the secretion of male sex hormones to the ovary.
(Jongh 1951:20)
It was the gonadal hypothesis, suggested by Zondek in 1934, that first broke with the dualistic concept of sex hormones. In this hypothesis it was proposed that the regular occurrence of female sex hormones in male organisms was the result of the conversion from male sex hormones into female ones (Zondek 1934b). The idea of conversion was strongly advocated by biochemists, who posited a close interrelationship between male and female sex hormones and brought about the general acceptance of the idea that the gonads produce both type of sex hormones. After 1937, the adrenals and the gonads of both sexes were considered as the sites of production of male as well as female sex hormones (Kochakian 1938; Parkes 1938).
This succession of hypotheses illustrates how the prescientific idea of a sexual duality located in the gonads was gradually reshaped into a new conceptualization of sex differences. In this period, scientists definitely broke with the cultural notion that the essence of femininity and masculinity was located only in the gonads. They suggested that the chemical messengers of masculinity and femininity were present in the adrenals as well as in the gonads of all organisms, rather than being restricted to the gonads of one sex. In the 1930s, scientists reshaped the original dualistic assumption of the sex- specific origin of sex hormones into a conceptualization in which the categories male and female were no longer considered mutually exclusive. By the end of the 1930s, scientists supported the idea that male bodies could possess female sex hormones and vice versa, thus for the first time combining the categories of male and female into one sex.
The debate over the sex-specific origin of sex hormones shows how the different disciplines played different roles in this controversy. Although the presence of female sex hormones in male bodies was reported by gynecologists and biologists, the biochemists took a key position in the debate on the sex-specific origin of sex hormones, as the following citation from the Amsterdam School illustrates:
In the second place I want to reflect on the question of whether the estrus-producing substance that is present in the organs and body fluids of men, and apparently has a function there, is really female sex hormone. In fact we know nothing more than that it can cause the same effects as female sex hormone. An identification can only be possible after the chemical isolation of this oestrus-producing substance from male products, which has not yet been done.
(Jongh 1934b:1,213)
Prior to the 1930s, the question of the identity of sex hormones could be addressed only by using the techniques of biological assays. Substances isolated from male urine which passed the biological assays specific for female sex hormones were defined as female sex hormones. It was only after 1929 that scientists could assess the identity of sex hormones with chemical methods, thanks to developments in organic chemistry in the area of steroid and lipoid compounds. Sex hormones—classified as steroids—could now be chemically identified and isolated (Long Hall 1975). Female sex hormones were first chemically isolated from the urine of horses and pregnant women in 1929. In 1932, English and German chemists classified female sex hormones as steroid substances, and a colon-metric test was developed to detect the presence of female sex hormone in organisms (Walsh 1985). Male sex hormones were first isolated from men’s urine in 1931 and were classified two years later in the same group of chemical substances as female sex hormones: the steroids.
In 1938, the Amsterdam School finally reported the isolation of female sex hormone from male urine. The delay had been mainly caused by the limited availability of raw material, a general obstacle to the chemical isolation of sex hormones, which could be surmounted only by scientists working in close cooperation with pharmaceutical companies. Elisabeth Dingemanse explained the problem in an article in Nature as follows:
The necessity arose shortly afterwards of identifying these active substances chemically. The small amounts in which these active substances occur in adult male urine has so far made this impossible…. Through the intervention of the N. V.Organon-Oss, for which we take this opportunity of expressing our thanks, it has been possible for us to process 17,000 litres of male urine.. In this way we succeeded in obtaining 6 milligrams of a single crystalline substance. This proved to be identical with oestrone (female sex hormone).
(Dingemanse et al. 1928:927)
Thus, the biochemists claimed to possess a definitive answer to the question of the identity of female sex hormone in male organisms. They defined female and male sex hormones as closely related chemical compounds, differing in just one hydroxyl group, which could be detected by chemical methods in both sexes. In this manner they broke with the dualistic concept of male and female as mutually exclusive categories (Figure 2.2).
|
|
|
