The Estrogen Provocation Study.
It arose from other studies which provoked a fall of LH in women, after being injected with estrogen, followed by a large rise.
The inference conveyed by popular accounts seems to be that it mimicked the positive feedback which occurs in menstruation. In quoting Dorners study it is suggested that the male homosexual hypothalamus does exactly the same thing when injected with female hormone, reacting in the manner of the female 'mating centre'.
How the object of sexual choice is related to a system of control for menstruation is unclear. Nevertheless it is suggested that the hypothalamus responded to estrogen dosage by producing more of the female hormone. Heterosexual men, it is said, show no such rise in female hormone levels.
So the first thing to make clear is that what was measured was the production of LH, which is not a specifically a female hormone. We have described a base level system, common to both men and women in which, only the end product is different because men have testicles and women have ovaries. Secondly LH is produced by the pituitary. Although one might expect the hypothalamus to be influenced, one needs to ask questions about the mechanism.
Dorner injected his subjects, 21 homosexual men, 5 bisexual and 20 heterosexual, with with 20mg Premarin (some four times more than the dose taken at any one time by HRT or TS's). A representation of his results is shown below.
Although the picture is not complete, the effect looks, to this author, exactly like the typical response of a first order negative feedback system to shock. After being driven down by the initial dose of Premarin, LH rebounds and overshoots. In other words, rather than something provoking the beginning of the female positive feedback, as some popular accounts suggest, it is the expectable operation of the basic negative feedback system. The difference is in the degree of damping.
The main criticism seems to be that it had nothing to with masculinisation or feminisation of the brain. Bancroft,(2) quotes a study by Gooren,(3) who showed that, with transsexuals, while before castration the response was as expected for the genetic sex, afterwards, it was in the opposite direction.
In other words rather than being a sexual difference in the hypothalamus, it was a function of the subject's general biochemical milieu.
Bland, J.,(1998) About Gender: The Estrogen Provocation Study.
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Web page copyright Derby TV/TS Group. Text copyright Jed Bland.
Last amended 08.04.98