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

This Article Full Text Full Text (PDF) All Versions of this Article: 71/5/1437    most recent biolreprod.104.029041v1 Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Albarracín, J.L. Articles by Rodríguez-Gil, J.E. Search for Related Content PubMed PubMed Citation Articles by Albarracín, J.L. Articles by Rodríguez-Gil, J.E. Agricola Articles by Albarracín, J.L. Articles by Rodríguez-Gil, J.E.

Gluconeogenesis-Linked Glycogen Metabolism Is Important in the Achievement of In Vitro Capacitation of Dog Spermatozoa in a Medium Without Glucose¹

Unit of Animal Reproduction,³ Department of Animal Medicine and Surgery, School of Veterinary Medicine, Autonomous University of Barcelona, Bellaterra, Spain Department of Biochemistry and Molecular Biology and IRBB,⁴ Scientific Park of Barcelona, University of Barcelona, Barcelona, Spain Instituto de Bioquímica,⁵ Facultad de Ciencias, Campus Isla Teja, Universidad Austral de Chile, Valdivia, Chile

In vitro capacitation of dog spermatozoa in a medium without sugars and with lactate as the metabolic substrate (l-CCM) was accompanied by a progressive increase of intracellular glycogen during the first 2 h of incubation, which was followed by a subsequent decrease of glycogen levels after up to 4 h of incubation. Lactate from the medium is the source for the observed glycogen synthesis, as the presence of [¹⁴C]glycogen after the addition to l-CCM with [¹⁴C]lactate was demonstrated. The existence of functional gluconeogenesis in dog sperm was also sustained by the presence of key enzymes of this metabolic pathway, such as fructose 1,6-bisphophatase and aldolase B. On the other hand, glycogen metabolism from gluconeogenic sources was important in the maintenance of a correct in vitro fertilization after incubation in the l-CCM. This was demonstrated after the addition of phenylacetic acid (PAA) to l-CCM. In the presence of PAA, in vitro capacitation of dog spermatozoa suffered alterations, which translated into changes in capacitation functional markers, like the increase in the percentage of altered acrosomes, a distinct motion pattern, decrease or even disappearance of capacitation-induced tyrosine phosphorylation, and increased heterogeneity of the chlorotetracycline pattern in capacitated cells. Thus, this is the first report indicating the existence of a functional glyconeogenesis in mammalian spermatozoa. Moreover, gluconeogenesis-linked glycogen metabolism seems to be of importance in the maintenance of a correct in vitro capacitation in dog sperm in the absence of hexoses in the medium.

¹ Partially supported by research grants from the Fondo Nacional de Ciencia y Tecnologí (Chile), FONDECYT 1010720, and from the Dirección de Investigación y Desarrollo (Universidad Austral de Chile), DID-UACH 200205.

² Correspondence: Joan E. Rodríguez-Gil, Unit of Animal Reproduction, Department of Animal Medicine and Surgery, School of Veterinary Medicine, Autonomous University of Barcelona, E-08193 Bellaterra, Spain. FAX: 34 935812006; juanenrique.rodriguez{at}uab.es