Glutathione-Independent Prostaglandin: RESULTS(4)
A 0.8-kilobase mRNA was detected only in the proximal caput epididymidis of both the ram (regions 0-1) (Fig. 4C) and the stallion (regions 0-2) (Fig. 7C). Testicular PGDS transcripts were found in stallions (not shown), but we were not able to detect signals in any rams. PGDS mRNA could be detected in the efferent ducts of all the horses studied, whereas the transcript was detected in only half the rams.
Regulation of the Expression and Synthesis of PGDS in the Vasa Efferentia and Epididymis
Regulation of PGDS expression by testicular factors and testosterone was studied with ipsilateral-ligated efferent ducts and with castrated and castrated-testosterone-supple-mented animals.
Ligation for 45 days and castration for 30 days induced a decrease in mRNA expression in the ram (Fig. 10). The protein secreted and detectable in the fluid of the proximal caput presented only the most basic isoforms found in the normal ram (Fig. 8, E and F). buy ventolin inhalers
In the stallion, ligation induced the disappearance of mRNA in the efferent ducts but did not affect the level of PGDS mRNA in the proximal caput (Fig. 11, A and B) or its secretion (not shown). After 1 mo of castration, PGDS mRNA expression disappeared from the epididymal proximal caput (Fig. 11C), and the protein was no longer detected by Western blotting in epididymal fluids (not shown). Messenger RNA expression (Fig. 11D) and protein secretion (not shown) reappeared in the caput epididymidis after 15 days of injection of testosterone.
FIG. 10. Detection of PGDS mRNA by Northern blot with the probe obtained by RT-PCR in total RNA from the efferent duct (VE) and from various epididymal regions on the normal side (A) and the ligated side (B) of an ipsilateral efferent duct-ligated ram and from a castrated ram (C).
FIG. 11. Detection of PGDS mRNA by Northern blot analysis with the specific probe obtained by RT-PCR in total RNA from the testis (T), efferent duct (VE), and epididymal regions of the normal side (A) and the ligated side (B) of an ipsilaterally efferent duct-ligated stallion, from a castrated stallion (C), and from a castrated-testosterone-supplemented stallion (D).