Journal ArticleDOI
Variations in sexual dimorphism in the skulls of rats subjected to malnutrition, castration, and treatment with gonadal hormones.
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TLDR
It is suggested that estradiol in females may counteract sexual cranial development and that its inhibitory effect may be additive to the testosterone deficit evoked by malnutrition.Abstract:
Two groups of weanling rats were subjected to malnutrition, one with periodic injections of testosterone (males) and the other with estradiol (females). Two other groups (castrated males or castrated females) received normal feedings. In control animals, the relative weights (mg/gm body weight) of testes, seminal vesicles, and ovaries were greater than in malnourished rats. However, relative weights of those organs in hormone-treated, malnourished animals were greater than in those subjected to malnutrition alone and still greater than in controls. Normal sexual cranial dimorphism (SCD) was decreased 16% by male castration, 23% by malnutrition, and 83% by estradiol treatment in malnourished females. On the other hand, normal SCD was increased 20% by female castration and more than 200% by testosterone treatment in malnourished males. All monosexual comparisons corroborated the bisexual range of distances found. Testicular but not ovarian secretions seemed to influence sexual cranial dimorphism. Malnutrition delayed SCD because of a deficiency of testosterone level in stressed males. It is suggested that estradiol in females may counteract sexual cranial development and that its inhibitory effect may be additive to the testosterone deficit evoked by malnutrition.read more
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Male Life History, Reproductive Effort, and the Evolution of the Genus Homo
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Evaluating Accuracy and Precisión in Morphologic Traits for Sexual Dimorphism in Malnutrition Human Skull: a Comparative Study
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References
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Journal ArticleDOI
Neural gonadal steroid actions.
TL;DR: Variability in the occurrence and distribution of particular neural hormonal sensitivities across species may be related to variations in the hormonal requirements for sexual differentiation and for activation of reproductive behaviors.
Journal ArticleDOI
Testosterone: a major determinant of extragenital sexual dimorphism
CW Bardin,JF Catterall +1 more
TL;DR: Testosterone rather than 5 alpha-dihydrotestosterone appears to be the major intracellular androgen in organs other than skin and reproductive tract, but other steroid metabolites and their receptors are required to produce the diverse tissue differences observed in males and females.
Journal ArticleDOI
Effects of Starvation in Rats on Serum Levels of Follicle Stimulating Hormone, Luteinizing Hormone, Thyrotropin, Growth Hormone and Prolactin; Response to LH-Releasing Hormone and Thyrotropin-Releasing Hormone
TL;DR: Serum levels in serum LH, FSH, TSH and prolactin in response to LHRH + TRH injection in acutely or chronically starved rats were equal to or greater than in the ad libitum fed controls, indicating that severe reductions in food intake result in decreased release of at least 5 anterior pituitary hormones.