Regulation of Na+,K+-ATPase in submandibular glands of hypophysectomized male mice by steroid and thyroid hormones.

Abstract

The effects of thyroid hormone, androgen, glucocorticoid, and mineralocorticoid on Na+,K+-AT€%e activity and on levels of its a-subunit protein (a1 isoform) in mouse submandibular gland (SMG) were studied by enzyme assay for ouabainsensitive ATP hydrolysis, by quantitative densitometric scanning of Western blots, and by immunohistochemistry. To define the specific regulatory effects of various pituitarydependent hormones on expression of Na',K+-ATPase in the SMG, we treated hypophysectomized (hypox) male mice with triiodo-L-thyronine (T3), 5 a-dihydrotestosterone (DHT) , dexamethasone (Den), and aldosterone (Ald), injected singly or in combination. Na+,K+-ATPase was confined to the duct system of the SMG. In intact mice there was a gender &rence in SMG Na',K+-ATPase, with levels of the enzyme's activity and of its a1-subunit being less in the glands of d e s . In males, hypophysectomy caused a rise in levels of Na+,K+-ATPase activity and in levels of the al-subunit protein of this enzyme, and in intensity of immunocytochemical staining for this subunit but there were no such changes in the SMG of hypox females. Changes caused by hormonal replacement to hypox males in Na+,K+-ATPase activity, lev-

Thyroid Hormone (3,5,3′-Triido-l-Thyronine) Masking/Inversion of Stimulatory Effect of Androgen on Expression of mk1, a True Tissue Kallikrein, in the Mouse Submandibular Gland*

“…In addition, the weight of the SMG was significantly decreased by about 30% (data not shown), consistent with our previous studies (32,37). The success of the Hypox was evident from the significant reduction in weights of the adrenal glands, seminal vesicles, and testes (data not shown).…”

An Overview of Autonomic Regulation of Parotid Gland Activity: Influence of Orchiectomy

“…We propose that the unchanged basal activity of Na + -K + -ATPase observed in the castrated group is due to the fact that only low-affinity binding sites are downregulated in castrated rats, in addition with an increase in affinity [Busch et al, 2004a]. This increase in [ 3 H]ouabain affinity may be related to castration-induced changes in the catalytic subunit [Kurihara et al, 1996].…”

“…4 ) [Busch et al, 2004a]. Castration induces an increase in the affinity of both high-and low-affinity binding sites and a decrease in the number of low-affinity binding sites for [ The Na + -K + -ATPase ␣ -subunit of the rat submandibular gland is regulated by steroid hormones [Kurihara et al, 1996]. We propose that the unchanged basal activity of Na + -K + -ATPase observed in the castrated group is due to the fact that only low-affinity binding sites are downregulated in castrated rats, in addition with an increase in affinity [Busch et al, 2004a].…”

EFFECTS OF CASTRATION ON CANNABINOID CB1 RECEPTOR EXPRESSION AND ON THE BIOLOGICAL ACTIONS OF CANNABINOID IN THE PAROTID GLAND

“…Phosphorylation of the α‐subunit by protein kinase A (cAMP activated) has been proposed to mediate regulation of the enzyme 29 . Kurikara et al 30 . described that the Na + /K + ‐ATPase α‐subunit of rat submandibular gland is regulated by steroid hormones.…”

“…Phosphorylation of the a-subunit by protein kinase A (cAMP activated) has been proposed to mediate regulation of the enzyme. 29 Kurikara et al 30 described that the Na + /K + -ATPase a-subunit of rat submandibular gland is regulated by steroid hormones. In addition, [ 3 H]-ouabain binding assays in parotid glands showed a decrease in the number of binding sites, with an increase in the affinity of the ligand, after castration.…”