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 Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sexton, T. J. Articles by Flipse, R. J. Search for Related Content PubMed PubMed Citation Articles by Sexton, T. J. Articles by Flipse, R. J.

Oxidative Metabolism of Glutamate by Testicular, Epididymal, and Ejaculated Bovine Spermatozoa in the Presence of Rete Testis Fluid and Seminal Plasma¹

Dairy Breeding Research Center, Department of Dairy Science, The Pennsylvania State University, University Park 16802

ABSTRACT

Spermatozoa were collected by cannulae from the rete testis and cauda epididymis of conscious dairy bulls and ejaculated spermatozoa were collected by artificial vagina. Spermatozoa were washed free of fluid and incubated with glutamate-U-¹⁴C at 37 C for 60 minutes. Although glutamate probably is not a major source of energy, metabolic responses of the three cell types were distinctly different. Oxygen uptake by both testicular and ejaculated spermatozoa suspended in rete tests fluid (pH 7.2) was greater (P< .05) than endogenous amounts for cells suspended in Krebs- Henseleit-Ringer buffer at pH 7.2. However, rete testis fluid had little effect on the oxygen uptake of spermatozoa from the cauda epididymidis. Seminal plasma reduced the respiration rate of ejaculated spermatozoa but did not affect that of the other cell types. Identified products of glutamate catabolism by testicular and cauda epididymal spermatozoa were aspartate, lactate, -ketoglutarate, succinate, and fumarate. Oxidation of glutamate- U-¹⁴C to ¹⁴CO₂ by all three cell types was depressed (P<.05) in the presence of rete testis fluid as compared to rates for cells suspended in buffer. However, when cells were suspended in seminal plasma, ¹⁴C0₂ formation was reduced (P<.05) only far testicular spermatozoa. Heat treatment of rete testis fluid did not eliminate its depressing effect on decarboxylation of glutamate-U-^l4C by testicular or ejaculated spermatozoa.

¹ Authorized for publication as Paper 3995 in the Journal Series of the Pennsylvania Agricultural Experiment Station. Research upon which this publication is based was performed pursuant to Contract NIH 69-2137 with the National Institutes of Health, Department of Health, Education and Welfare and was supported in part by Research Grant HD 01356-07.

² Present address: Poultry Research Branch, ARS, USDA, Beltsville, Maryland 20705.