Differential Regulation of Carbonic Anhydrase II by Androgen and Estrogen in Dorsal and Lateral Prostate of the Rat*

Abstract

Hormone regulation of carbonic anhydrase II (CA II) was studied in rat dorsal and lateral prostate. CA II is a major soluble protein in these accessory sex glands. The immunoelectronmicroscopy showed that CA II is expressed in their epithelial cells only. For studies on hormone regulation, adult male rats were castrated for 2 or 7 days. Groups of 7-day castrates and normal rats were treated daily either with testosterone or 17-beta-estradiol for 6 days and 2-day castrates for 1 day. CA II protein was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and quantified by RIA. The levels of CA II mRNA were studied by Northern blotting and hybridization of total RNA with a 32P-labeled mouse CA II cDNA clone. Castration of the rats decreased the concentration of CA II in lateral prostate but increased in dorsal prostate. These changes were reversed in both prostatic lobes by testosterone treatment. Estrogen treatment of castrated rats enhanced CA II concentration in lateral prostate but no effects were seen in the dorsal prostate of the same animals. In normal rats estrogen increased CA II concentration of dorsal prostate but there was no change in lateral prostate. Corresponding changes were observed in the levels of CA II mRNA in both tissues. The morphometric analyses showed that the castration- and hormone-induced changes of the mRNA and protein levels of the exclusively epithelial CA II could not be explained by any alterations in the proportions of epithelial and stromal components of the glands after hormone manipulations. The results demonstrate the differential steroid regulation of CAII in two prostatic lobes. Androgen regulates the expression of CAII at messenger RNA level, but the responses of CAII to testosterone are opposite in dorsal and lateral prostate. Estrogen increases CA II expression in lateral prostate but in dorsal prostate the castration-like effects of estrogen on CAII expression are probably indirect.

Identification of Rat Prostatic Secreted Proteins Using Mass Spectrometric Analysis and Androgen‐Dependent mRNA Expression

“…Further investigations are required to understand their androgen‐responsive mechanisms. The CA2 expression exemplifies the differential androgen dependency of the transcription between lobes, as previously reported (Harkonen et al, 1991), which showed that CA2 mRNA expression was up‐regulated by androgen in the LP, whereas it was down‐regulated in the DP in SD rats. In the present study, there were comparable responses in CA2 mRNA in the LP but no significant changes in the DP, which may be because of differences in androgen dosages or the mRNA quantification methods.…”

“…The differential responses of CA2 to androgen suggest the lobe-specific function of this protein. Estrogen and the other hormone may be also involved in the androgen regulation of CA2 (Harkonen et al, 1991).…”

Carbonic anhydrases in meningiomas: association of endothelial carbonic anhydrase II with aggressive tumor features

“…14 The regulatory mechanisms are complex, however, because androgens induce CA II expression in some organs and inhibit it in others. 10 Expression of CA II has recently been found to be common in the endothelial cells of highgrade oligodendrogliomas and diffuse infiltrating astrocytomas. 8 Carbonic anhydrase II positivity also correlated with tumor grade and poor prognosis; CA II reactivity was highest in high-grade astrocytomas, which are vascularized tumors containing necrotic areas.…”

Aging-associated changes in gene expression in the ACI rat prostate: Implications for carcinogenesis

“…In the rat, prolactin receptor is present in both dorsal (DP) and lateral (LP) prostate [47]. This fact is important because the hormone responsiveness of distinct rat prostate lobes has been shown to be different [48,49] and the dorsal and lateral parts of rat prostate are considered most sensitive to prolactin [20,50]. Prolactin serum levels increase with age and are associated with normal development and growth of the prostate and with zinc and citrate accumulation in the prostate [51][52][53][54].…”