Thesis (Ph.D.)--Boston University. / The literature concerning the physiology of the mammalian adrenal cortex is voluminous. However, little has been reported on the physiology of the adrenal cortex of the hamster, Mesocricetus auratus. The present investigation of the effects of adrenalectomy in the hamster was initiated in order that fundamental data such as survival time, electrolyte levels, and changes in estrus cycle of the female could be determined. Since the golden hamster is being used more and more as a laboratory animal, this data would serve as a basis for further investigation. All results obtained in the study of the hamster are compared and contrated to those reported for the rat, the most commonly used laboratory animal in endocrinological investigation. A great many phenomena have been observed by endocrinologists which have demonstrated an apparent interrelationship between the adrenal cortices and gonads of mammals. These phenomena are so numerous that Parkes (1945) was forced to adopt an artificial classification of these interrelationships in orer to review the field with some order and clarity. The effects of adrenalectomy in the hamster were such that it was felt that in this study greater emphasis should be placed on the interrelationships between the gonads and the adrenal cortices than on any other aspect of the adrenal cortical physiology of the animals. It was hoped thereby that the mechanisms involved in these interrelationships would be further elucidated. [Truncated]

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published_or_final_version / Anatomy / Master / Master of Philosophy

published_or_final_version / Anatomy / Master / Master of Philosophy

Thesis (Ph. D.)--Illinois State University, 1972. / Title from title page screen, viewed Sept. 23, 2004. Dissertation Committee: Mathew J. Nadakavukaren, John L. Frehn (co-chairs), Herman Brockman, Arthur Merrick, Joseph Tsang. Includes bibliographical references (leaves 139-148) and abstract. Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 160-192).

Abstract Although the genetic sex of an embryo is determined at conception by the presence or absence of the Y chromosome, both females and males have bipotential, undifferentiated gonads early in their development. Genes and testicular hormones direct differentiation into either testes or ovaries. The first relevant gene to be identified was the Y-linked master regulatory gene, SRY, since when several other genes have been found to be of importance for sex determination. The primary aim here was to identify the role of Wnt-4 in the development of the gonad and adrenal gland. Wnt-4 was found to be expressed in the developing gonad, the Müllerian duct and the adrenal gland, in addition to the kidney, pituitary gland and mammary gland as observed earlier. Expression in the gonad was found to be regulated in a sex-specific manner. After sex determination Wnt-4 was downregulated in the testis, but the expression persisted until birth in the ovary. Wnt-4-deficient female mice demonstrated a partial female-to-male sex reversal and a reduction in the number of oocytes, while the Müllerian duct was absent from both sexes. Lack of Wnt-4 in the adrenal gland led to reduced aldosterone production, indicating abnormal development of the zona glomerulosa. Flutamide administration to pregnant Wnt-4 heterozygote females was shown to partially restore the sex reversal. The results suggest that female development is not a default pathway but needs active signalling, in which Wnt-4 plays an essential role.

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy