Journal of Andrology, Vol. 26, No. 6, November/December 2005
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.04156
Tungstate Treatment Improves Leydig Cell Function in Streptozotocin-Diabetic Rats
JOAN BALLESTER*,
JORGE DOMÍNGUEZ
,
M. CARMEN MUñOZ
,
MERITXELL SENSAT*,
TERESA RIGAU*,
JOAN J. GUINOVART
AND
JOAN E. RODRÍGUEZ-GIL*
From the * Unit of Animal Reproduction, Department
of Animal Medicine and Surgery, School of Veterinary Medicine, Autonomous
University of Barcelona, Bellaterra, Spain; and the
Department of Biochemistry and Molecular
Biology and IRBB, Barcelona Science Park University of Barcelona, Barcelona,
Spain.
|
Correspondence to: Dr 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. |
Oral administration of sodium tungstate to adult male
streptozotocin-diabetic rats for 3 months normalized serum levels of glucose,
insulin, luteinizing hormone, and follicle-stimulating hormone. These effects
were accompanied by an increase in reproductive performance, which was related
to a strong improvement in Leydig cell function markers, such as the recovery
of the number of Leydig cells and serum testosterone levels. Moreover, this in
vivo recovery was related to a concomitant increase in the cell expression of
insulin receptors. Tungstate treatment did not modify Leydig cell function in
healthy rats. Furthermore, the addition of tungstate or insulin to the mTLC-1
cell line from Leydig cell origin increased the phosphorylation states of
MAP-kinase and glycogen synthase kinase-3. Our results indicate that tungstate
treatment in diabetic rats leads to a recovery of reproductive performance by
increasing the number of Leydig cells. This increase contributes to the
recovery of their functionality, thereby improving the overall function of
these cells. We propose that this improvement is caused by the combined effect
of the tungstate-induced normalization of insulin glucose and luteinizing
hormone serum levels and a direct action of the effector on Leydig cells
through modulation of at least MAP-kinase and glycogen synthase kinase-3
activities.
Key words: Diabetes, male, reproductive performance
Copyright © 2005 by The American Society of Andrology.