The growth of individual seminal vesicle epithelial cells and their proliferation

Effect of androgen concentration on seminal vesicle blood flow in rats—establishment of new highly sensitive simultaneous androgen measurement method

OBJECTIVES

To clarify the effect of androgen concentration on blood flow regulation in seminal vesicles and to identify the androgen most responsible for this effect.

METHODS

The androgen concentrations in the seminal vesicles and the seminal vesicle blood flow were measured at 0, 3, 6, 12, 24, 48, and 72 hours after castration. The androgen concentration was measured with a newly developed highly sensitive simultaneous androgen quantification method that uses liquid chromatography-tandem mass spectrometry. The blood flow was measured with the radioactive microsphere injection method. The change in seminal vesicle blood flow in 6-hour castrated rats after administration of 3 mg/kg testosterone, 3 mg/kg dihydrotestosterone (DHT), 3 mg/kg dehydroepiandrosterone, or 3 mg/kg testosterone plus 20 mg/kg finasteride was evaluated.

RESULTS

A correlation was observed between the DHT concentration and blood flow in the rat seminal vesicle after castration. The DHT concentration and blood flow decreased after castration to 31.6% and 37.9%, respectively, of the normal level at 6 hours. The decline in DHT concentration and blood flow decreased further thereafter to 2.2% and 18.1%, respectively, of the normal level at 72 hours. Both testosterone and DHT fully restored the organ blood flow in castrated rat seminal vesicles. However, the blood-flow-increasing effect of testosterone was attenuated by more than 50% when administered in combination with finasteride. Dehydroepiandrosterone did not increase seminal vesicle blood flow.

CONCLUSIONS

The results of our study showed a strong correlation between the organ DHT concentration and blood flow in rat seminal vesicles. Of the various androgens, the most active androgen in the regulation of seminal vesicle blood flow was DHT.

Sexually dimorphic expression of co-repressor Sin3A in mouse kidneys

Using Western blot analysis we found transcriptional co-repressor Sin3A to be expressed at a higher level in male mouse kidney than in females. HDAC1 (histone deacetylase 1) protein, another co-repressor forming complexes with Sin3A, was not higher in males. No sex differences in Sin3A expression were found after gonadectomy, suggesting that gonadal secretions in adulthood cause the sex difference in kidney expression of Sin3A. In contrast, HDAC1 levels were higher in castrated gonadal males than in females, which presumably reflects a long-lasting differentiating effect of testicular secretions in early development on this protein in kidneys. In gonadectomized mice in which sex chromosome complement (XX vs. XY) is independent of gonadal type (testes vs. ovaries), there was no difference in the level of Sin3A or HDAC1 expression in kidney in XX or XY mice of the same gonadal sex.

Castration-resistant secretion in the hamster seminal vesicle does not depend on androgens

The secretory activity of seminal vesicles (SV) in the castrated hamster was studied by stereological analysis and biochemical approaches following treatment with cyproterone acetate (CPA) and adrenalectomy in order to investigate whether extra-testicular androgens are responsible for castration-resistant protein secretion. Treatment of castrated animals with CPA decreased the size of secretory granules and increased the number of apical granules, though neither the absolute nor the relative volume of all the components analysed was changed. In addition, CPA-treatment increased the amount of protein exocytosed by SV in castrated animals, though total protein synthesis remained unchanged. Adrenalectomy neither suppressed secretion nor induced any further ultrastructural changes in the SV epithelium. Our results demonstrate that secretory activity of the hamster SV following castration is not controlled by extra-testicular androgens and suggest that SV secretory proteins, which are heterogeneous with regard to their sensitivity to androgen withdrawal, might be regulated differentially by androgens.