This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by HERNANDEZ, O. Articles by ROSADO, A. Search for Related Content PubMed PubMed Citation Articles by HERNANDEZ, O. Articles by ROSADO, A.

Polyamine Synthesis and Polysome Patterns in the Rat Uterus During the Estrous Cycle¹

Departamento de Investigation Cientifica I.M.S.S. Mexico D.F. Apdo postal 66-737, Mexico

Abstract

Ornithine decarboxylase activity and polysome patterns of the rat uterus were studied during the normal estrous cycle. Specific and per cell activity of ornithine decarboxylase at diestrus I was almost nil. The activity increases notably at diestrus II (22 nmoles/mg DNA/hr) and peaks at pro—estrus (98 nmoles/mg DNA/ hr). Then the activity decreases as rapidly as it increased, being possible to postulate that synthesis of this enzyme stops at some time during oestrus. The increase in ornithine decarboxylase activity is accompanied by an increase in the polyamine pools, putrescine concentration tripled and spermine and spermidine concentrations doubled from diestrus II up to pro—estrus. The concentration of the polyamines was kept constant during estrus and thereafter gradually decreased, reaching the lowest levels at diestrus II. The polysome pattern exhibits drastic changes that can be correlated with the stabilizing role of the polyamines. Diestrus II shows a clear absence of heavy polysomes. This behavior contrasts with that observed at pro—estrus, when heavy polysomes of up to 8 ribosomal units were observed. It is concluded that in the normal cycling rats the changes found in the studied parameters parallel the changes that may be induced in the laboratory animal by the external administration of hormones. (Endocrinology 92: 1107, 1973)

Footnotes

¹ Supported in part by a grant from the Ford Foundation.

² This paper will be included as a part of a Thesis to be submitted to the Graduate Council of the Escuela Nacional de Ciencias BiolÓgicas del Instituto Politecnico Nacional in partial fulfillment of the requirements for the D.Sc. degree.

Received June 12, 1972.