HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ogilvie, M. L. Articles by Hoekstra, W. G. Search for Related Content PubMed Articles by Ogilvie, M. L. Articles by Hoekstra, W. G.

Tissue Incorporation and Excretion of Tritium-Labeled Progestins in Rabbits, Sheep and Swine^{1, 2,}

University of Wisconsin, Madison⁴

Abstract

The excretion and tissue distribution of 7-H³-labeled progestins were studied in rabbits, sheep and swine. Progesterone (0.1 and 5.1 mg.) and 6-methyl-17-acetoxyprogesterone (1.0 mg.), with or without estrogen pretreatment were studied in ovariectomized rabbits. There was no significant effect of progesterone level on the excretion or tissue concentration of radioactivity. Pretreatment with estrone significantly increased the accumulation of radioactive progesterone and MAP or their metabolites in some, but not all, tissues. The major excretory pathway of radioactivity from subcutaneously injected progesterone-7-H³ was by way of the urine, while radioactivity from MAP-7-H³ was excreted primarily in the feces. With ewes and gilts, the radioactivity from a single oral dose of MAP was excreted almost exclusively in the feces. Less than 2.5% (ewes) and 10% (gilts) of the dose was voided in the urine by the end of 5 and 7 days, respectively. Peak incorporation of MAP or its metabolites occurred in the tissues of the ewes at 30 hr. and in the gilts at 8 hr. post-treatment. After 120 and 168 hr. in the ewes and gilts, respectively, only a very small amount of radioactivity remained. Pretreatment of ewes with 17 ß-estradiol resulted in higher concentrations of MAP or its metabolites in most tissues. Results from these experiments suggest that large concentrations of progesterone and MAP or their metabolites are not accumulated in the tissues, nor are they retained for extensive periods of time.

¹ Published with the approval of the Director of the Wisconsin Agricultural Experiment Station, Madison.

² These studies were supported in part by grants from the Wisconsin and Minnesota Cooperative Bull Studs and the Upjohn Company, Kalamazoo, Michigan. The authors express appreciation to The Upjohn Company for supplying the radioactive materials, and to M. M. Oloufa for conducting preliminary experiments.

³ Present address: Veterinary Research and Development, The Upjohn Company, Kalamazoo, Michigan.

⁴ Departments of Biochemistry, Meat and Animal Science (Paper No. 407) and Division of Genetics cooperating.