In vitro progesterone metabolism by avian testicular tissue

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Title In vitro progesterone metabolism by avian testicular tissue
Publication Type thesis
School or College School of Medicine
Department Biochemistry
Author Fevold, Harry Richard
Date 1961-08
Description It has been shown by in vitro incubations that cell-free homogenates of testicular tissue from the English sparrow (Passer domesticus) are capable of synthesizing androgenic steroid hormones for 4-pregnen-3,20-dione-4-C14 by a pathway involving 17?-hydroxylation, cleavage of carbons 20 and 21 to form 4-androstein-2, 17-dione, and reduction of the 17-ketone to form 4-androsten-17?-ol-3-one. The only exogenous cofactor required for this sequence of reactions in reduced triphosphopyridinenucleotide. In addition, both 4-pregnen-3, 20-dione, and 4-pregnen-17?-ol-3, 20-dione are reduced at the 20-ketone to form 4-pregnen-20?-ol-3-one, 4-pregnen-20?-ol-3-one, 4-Pregnen-17?, 20?-diol-3-one, and 4-pregnen-17?, 20?-diol-3-one. Two other products of progesterone metabolism believed to be 4-pregnen-20?-ol-3-one and 4-pregnen-20?-ol-3-one with a second hydroxyl at a position in the steroid nucleus have been incompletely identified. The variation of the testicular content of the 17?-hydroxylase and the two progesterone-20-ketone reductases over a wide range of natural and artificial testicular stimulation was determined. It was found that on a milligram of protein basis the 17?-hydroxylase decreased by a factor of 10 with an increase in testis weight from 7.2 to 480 milligrams, whereas the 20-ketone reductases remained relatively constant or decreased to a musch lesser extent, by a factor of two, over similar testicular weight changes. Calculated on the basis of enzyme content per bird by use of an average combined testicular weight, the total testicular 17?-hydroxylase increased by a factor of three to four, while the 20-ketone reductases increased by a factor of twenty to forty when the mean testicular weight increased from 7.2 to ca. 500 milligrams. Artificial testicular simulation with human chorionic gonadotropin stimulation both the 17?-hydroxylase and 20-ketone reductases, but appeared to have greater effect on the 17?-hydroxylase.
Type Text
Publisher University of Utah
Subject Progesterone
Subject MESH Birds; Progesterone
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "In vitro progesterone metabolism by avian testicular tissue". Spencer S. Eccles Health Sciences Library.
Rights Management © Harry Richard Fevold.
Format application/pdf
Format Medium application/pdf
Format Extent 4,108,746 bytes
Identifier undthes,3909
Source Original University of Utah Spencer S. Eccles Health Sciences Library (no longer available)
Funding/Fellowship National Heart Institue predoctoral fellowship HF-9392
Master File Extent 4,108,766 bytes
ARK ark:/87278/s6c24z7v
Setname ir_etd
ID 191084
Reference URL https://collections.lib.utah.edu/ark:/87278/s6c24z7v
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