Effects of time of L-ornithine administration on the diurnal rhythms of plasma growth hormone, melatonin, and corticosterone levels in mice.

The synthesis and secretion of many hormones such as growth hormone (GH), melatonin, and corticosterone, exhibit temporal variations over each day and night. Oral administration of several nutritional factors, including L-ornithine, modulates these hormonal secretions and induces an acute increase in plasma GH levels. However, the impact of L-ornithine on the diurnal rhythms of hormone secretion remains unclear.

Low-dose menaquinone-4 improves γ-carboxylation of osteocalcin in young males: a non-placebo-controlled dose-response study.

Background: Menaquinone-4 is a type of vitamin K that has a physiological function in maintaining bone quality via γ-carboxylation of osteocalcin. However, little is known about the beneficial effect of intake of dosages below1500 μg/day.

Findings: Fifteen healthy males aged 25.

In vitro recapitulation of the urea cycle using murine embryonic stem cell-derived in vitro liver model.

Ammonia, a toxic metabolite, is converted to urea in hepatocytes via the urea cycle, a process necessary for cell/organismal survival. In liver, hepatocytes, polygonal and multipolar structures, have a few sides which face hepatic sinusoids and adjacent hepatocytes to form intercellular bile canaliculi connecting to the ductules. The critical nature of this three-dimensional environment should be related to the maintenance of hepatocyte function such as urea synthesis.

Low-dose vitamin K2 (MK-4) supplementation for 12 months improves bone metabolism and prevents forearm bone loss in postmenopausal Japanese women.

Menaquinone-4 (MK-4) administered at a pharmacological dosage of 45 mg/day has been used for the treatment of osteoporosis in Japan. However, it is not known whether a lower dose of MK-4 supplementation is beneficial for bone health in healthy postmenopausal women. The aim of this study was to examine the long-term effects of 1.

Effect of dietary ornithine on the brain protein synthesis rate in hypophysectomized aged rats.

The purpose of this study was to determine whether the regulation of brain protein synthesis is mediated through changes in the plasma concentration of growth hormone (GH) when dietary ornithine treatment is manipulated in the hypophysectomized or sham-operated aged rats. Experiments were done on four groups of hypophysectomized and sham-operated (24-wk-old) male rats given 0% or 0.7% ornithine-HCl added to a 20% casein diet.

Dietary ornithine affects the tissue protein synthesis rate in young rats.

The purpose of this study was to determine whether ornithine affects the rate of tissue protein synthesis in male rats. Two experiments were done on five or two groups of young rats (5 wk) given diets containing 0.15, 0.

Increasing effect of an oral intake of L-hydroxyproline on the soluble collagen content of skin and collagen fragments in rat serum.

We examined the effects of oral L-hydroxyproline (Hyp) on collagen in the body. After 2 weeks' administration of Hyp (0.5 or 1 g/kg) to F344 male rats, the soluble collagen content of the skin had increased, and the serum concentration of collagen peptides was correlated with the skin content of soluble collagen.

Orally administered L-ornithine reduces restraint stress-induced activation of the hypothalamic-pituitary-adrenal axis in mice.

In a previous study, we confirmed that orally administered L-ornithine can be transported into the brain of mice. In addition, orally administered L-ornithine, within a limited dose range, had an anxiolytic-like effect in the elevated plus-maze test. However, the mechanism by which orally administered L-ornithine reduced the stress response in mice is still unclear.

Orally administered L-ornithine elevates brain L-ornithine levels and has an anxiolytic-like effect in mice.

Intracerebroventricular injection of L-ornithine has demonstrated sedative and hypnotic effects in neonatal chicks exposed to acute stressful conditions. However, whether orally administered L-ornithine can reduce acute mental stress remains to be defined. To clarify the nutritional importance of L-ornithine in controlling the stress response, in Experiment 1 we first investigated whether orally administered L-ornithine can be transported into the brain of mice.

Sex differences in behavioral and corticosterone responses to mild stressors in ICR mice are altered by ovariectomy in peripubertal period.

Among rodents, females are generally considered to be highly responsive in terms of emotionality under stressful conditions, and have higher corticosterone levels and activity. In this study, we examined sex differences in mice by evaluating anxiety behaviors and corticosterone responses to mild stressors. In our first experiment, we analyzed the behavioral and corticosterone responses to the elevated plus-maze test and open-field test in male and female mice, and compared sex differences.

Central L-ornithine, but not polyamines, induces a hypnotic effect in neonatal chicks under acute stress.

To clarify whether L-ornithine and/or its metabolite involves sedative and hypnotic effects under social separation stress, the effects of intracerebroventricular (i.c.v.

Wheel-running activity increases with social stress in male DBA mice.

Social affiliation-avoidance behaviors are essential indices of sociality. We examined changes in social affiliation-avoidance behaviors in an open-field apparatus while simultaneously measuring wheel-running activity. Recent studies suggest that mice increase wheel-running activity in stressful situations; thus, we hypothesized that wheel-running activity would reflect a state of social stress and avoidance.

Expression of programmed death 1 ligands by murine T cells and APC.

Programmed death 1 (PD-1) is a new member of the CD28/CTLA-4 family, which has been implicated in the maintenance of peripheral tolerance. Two ligands for PD-1, namely, B7-H1 (PD-L1) and B7-DC (PD-L2), have recently been identified as new members of the B7 family but their expression at the protein level remains largely unknown. To characterize the expression of B7-H1 and B7-DC, we newly generated an anti-mouse B7-H1 mAb (MIH6) and an anti-mouse B7-DC mAb (TY25).