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Role of 1α,25(OH) 2 vitamin D 3 on α-[1- 14C]MeAIB accumulation in immature rat testis
Ist Teil von
Steroids, 2009, Vol.74 (2), p.264-269
Ort / Verlag
Elsevier Inc
Erscheinungsjahr
2009
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
1,25D
3 is critical for the maintenance of normal reproduction since reduced fertility is observed in male rats on a vitamin D-deficient diet. Vitamin D-deficient male rats have incomplete spermatogenesis and degenerative testicular changes. In the present study we have examined the ionic involvement and intracellular messengers of the stimulatory effect of 1,25D
3 on amino acid accumulation in immature rat testis. 1,25D
3 stimulates amino acid accumulation from 10
−12 to 10
−6
M by increasing the slope to reach a maximum value at 10
−10
M, as compared to the control group. No effect was observed at a lower dose (10
−13
M). Time-course showed an increase on amino acid accumulation after 15, 30, and 60
min of incubation with 1,25D
3 (10
−10
M). 1,25D
3 stimulated amino acid accumulation in 11-day-old rat testis but not in testis that were 20 days old. Cycloheximide totally blocked the 1,25D
3 action on amino acid accumulation. Furthermore, a localized elevation of cAMP increased the stimulatory effect of 1,25D
3 and the blockage of PKA nullified the action of the hormone. In addition, 1,25D
3 action on amino acid accumulation was also mediated by ionic pathways, since verapamil and apamine diminished the hormone effect. The stimulatory effect of 1,25D
3 on amino acid accumulation is age-dependent and specific to this steroidal hormone since testosterone was not able to change amino acid accumulation in both ages studied. This study provides evidence for a dual effect for 1,25D
3, pointing to a genomic effect that can be triggered by PKA, as well as to a rapid response involving Ca
2+/K
+ channels on the plasma membrane.