OBJECTIVE To determine if supplemental intraarticular α2-macroglobulin (α2 M) has a chondroprotective effect in a rat model of osteoarthritis (OA). METHODS Using Western blotting, mass spectrometry, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry, α2 M was identified as a potential therapeutic agent through a comparison of α2 M concentrations in serum, synovial fluid (SF),...

The Na,K-ATPase is essential for the contractile function of skeletal muscle, which expresses the α1 and α2 subunit isoforms of Na,K-ATPase. The α2 isozyme is predominant in adult skeletal muscles and makes a greater contribution in working compared with noncontracting muscles. Hindlimb suspension (HS) is a widely used model of muscle disuse that leads to progressive atrophy of postural skeleta...

The presynaptic active zone mediates synaptic vesicle exocytosis, and modulation of its molecular composition is important for many types of synaptic plasticity. Here, we identify synaptic scaffold protein liprin-α2 as a key organizer in this process. We show that liprin-α2 levels were regulated by synaptic activity and the ubiquitin-proteasome system. Furthermore, liprin-α2 organized presynapt...

The α2 isoform of Na,K-ATPase plays a crucial role in Ca(2+) handling, muscle contraction, and inotropic effects of cardiac glycosides. Thus, structural, functional, and pharmacological comparisons of α1, α2, and α3 are of great interest. In Pichia pastoris membranes expressing human α1β1, α2β1, and α3β1 isoforms, or using the purified isoform proteins, α2 is most easily inactivated by heating ...

Growing male lambs were fed with diets containing 14.0, 10.8 and 7.6% protein for 3 months to determine their effects on the content of hypothalamic LHRH and SRIH and pituitary LH and GH, using immunohistochemical methods. Lowering the concentration of dietary proteins caused marked changes in the immunoreactivity of these hormones. The immunoreactive (IR) content of LHRH stored in the median e...

Tamoxifen treatment for breast cancer may induce ovarian cysts and supraphysiological levels of serum estrogen. We report successful management with luteinizing hormone-releasing hormone (LHRH) agonist of ovarian hyperstimulation induced by tamoxifen. A 49-year-old woman was operated on for invasive ductal carcinoma of the right breast. She received breast irradiation and adjuvant tamoxifen the...

Sexually mature rams were left intact, castrated (wethers), castrated and implanted with testosterone, or castrated, implanted with testosterone and pulse-infused every hour with LHRH. Serum concentrations of LH increased rapidly during the first week after castration and at 14 days had reached values of 13.1 +/- 2.2 ng/ml (mean +/- s.e.m.) and were characterized by a rhythmic, pulsatile patter...

More than 80% of human ovarian cancers express LHRH and its receptor as part of a negative autocrine mechanism of growth control. This study was conducted to investigate whether LHRH affects apoptosis in ovarian cancer. EFO-21 and EFO-27 ovarian cancer cells were treated with LHRH agonist Triptorelin or with cytotoxic agent Doxorubicin in the absence or presence of Triptorelin. Apoptotic cells ...

The activation of transforming growth factor alpha (TGFalpha)-erbB-1 and neuregulin-erbB-4 signaling pathways in hypothalamic astrocytes has been shown to play a key role in the process by which the neuroendocrine brain controls luteinizing hormone-releasing hormone (LHRH) secretion. Earlier studies suggested that tanycytes, an ependymoglial cell type of the median eminence, regulate LHRH relea...