Seasonal changes in inhibin activity in seminal plasma and serum concentrations of FSH, LH and testosterone in the male goat (Capra hircus)

Inhibin activity in goat seminal plasma was measured by in vitro assay throughout successive 9 months and its relationship with the serum FSH, LH and testosterone concentrations was investigated. Total inhibin activity (TIA) in seminal plasma gradually increased from spring to summer, reduced in autumn (P<0.05) and recovered toward winter (P<0.05). Serum FSH and LH reached a peak in mid-summer (P<0.01) and returned to the low levels in autumn. Serum testosterone also increased in mid-summer and kept the high levels until the early winter (P<0.05). Some positive correlation was found in monthly levels between seminal TIA and serum FSH (r=0.305; P<0.05). Results suggest that the summer increase of inhibin activity in seminal plasma relates with the mid-summer rise of serum FSH levels in the male goat.     

Immunocytochemical localization of ornithine transcarbamylase in rat intestinal mucosa. Light and electron microscopic study

We investigated light and electron microscopic localization of ornithine transcarbamylase (OTC) in rat intestinal mucosa. In the immunoblotting assay of OTC-related protein, a single protein band with a molecular weight of about 36,500 is observed in extracts of liver and small intestinal mucosa but is not observed in those of stomach and large intestine. For light microscopy, tissue slices of the digestive system were embedded in Epon and stained by using anti-bovine OTC rabbit IgG and the immunoenzyme technique. For electron microscopy, slices of these and the liver tissues were embedded in Lowicryl K4M and stained by the protein A-gold technique. By light microscopy, the absorptive epithelial cells of duodenum, jejunum, and ileum stained positively for OTC, but stomach, large intestine, rectum, and propria mucosa of small intestine were not stained. Electron microscopy showed that gold particles representing the antigenic sites for OTC were confined to the mitochondrial matrix of hepatocytes and small intestinal epithelial cells. However, the enzyme was detected in mitochondria of neither liver endothelial cells, submucosal cells of small intestine, nor large intestinal epithelial cells. Labeling density of mitochondria in the absorptive epithelial cells of duodenum, jejunum, and ileum was about half of that in liver cells.     

Further studies on the relationship between tyrosine supply and catecholamine production in cultured adrenal chromaffin cells.

To elucidate a possible role of tyrosine supply as a factor modulating catecholamine biosynthesis in the adrenergic cell, the transport of [14C]tyrosine into cultured bovine adrenal chromaffin cells was first examined, and the relationship between [14C]tyrosine transport and [14C]catecholamine formation was then investigated. Under the conditions which were routinely employed to determine the rate of catecholamine biosynthesis, tyrosine was taken up into the cells in a manner independent of extracellular Na+ and Ca2+, and this uptake was also insensitive to ouabain and various metabolic inhibitors. The stimulation of these cells with high K+ and other secretagogues caused no significant alteration in the uptake. While, tyrosine transport was markedly inhibited by tyrosine analogues and other L-aromatic amino acids, and this inhibition was accompanied by the reduction of [14C]catecholamine formation. In contrast, tyrosine transport was markedly enhanced by flavone, and this enhancement was also accompanied by the augmentation of catecholamine production under the same experimental conditions. These results seem to indicate that the transport of tyrosine into the cells may be closely related to catecholamine formation within the cells, thus providing an evidence for a possible role of tyrosine supply as one of the factors affecting catecholamine production in the adrenal chromaffin cell.     

Pregnancy diagnosis by the ultrasonographical device and observation of fetal growth in the squirrel monkey (Saimiri sciureus)

This paper describes usefulness of the ultrasonographical device (USD) for the diagnosis of pregnancy and the observation of fetal growth in the squirrel monkeys (Saimiri sciureus) conceived under group breeding conditions. Pregnancy was diagnosed on the basis of the detection of gestational sac (GS) in the uterus. The GS was first detected 127 +/- 10 days before delivery. The heart beat of embryo was detected around 114 days before delivery. It was able to judge conditions of fetal growth by measuring the size of GS and the biparietal diameter. No difference in uterine size between nonpregnant and pregnant animals was observed 135 days before delivery.     

Receptor-mediated calcium signal playing a nuclear third messenger in the activation of antigen-specific B cells.

We have studied receptor-mediated calcium signals in antigen-specific B cells (trinitrophenol-specific B cell clone, TP67.21) using a confocal fluorescence microscope with an argon ion laser (488 nm) and a He-Cd laser (325 nm). Confocal fluorescence images of fluo-3 loaded B cells, excited by an argon ion laser, became much brighter and more nonhomogeneous than those before antigen stimulation. Time-dependent fluorescence changes in intensities were abrupt and quite similar to the patterns of the intracellular calcium ion concentration [Ca2+]i observed by a conventional fluorescence microscope using fura-2. From the morphological patterns of the calcium images, the parts of the bright fluorescence seemed to belong to the nucleus in B cells. To confirm the above events we measured the confocal fluorescence images of the nucleus. From the fluorescence images of co-loaded Hoechst 33342 (a DNA-specific fluorescent probe), which excited by a He-Cd laser, the brighter parts of the fluo-3 fluorescence intensities were identified to the nucleus in B cells. This suggested the possibility that the increased intranuclear calcium ions may play a nuclear third messenger in B cells.     

Unique T Cells with Unconventional Cytokine Profiles Induced in the Livers of Mice during Schistosoma mansoni Infection

During infection with Schistosoma, serious hepatic disorders are induced in the host. The liver possesses unique immune systems composed of specialized cells that differ from those of other immune competent organs or tissues. Host immune responses change dramatically during Schistosoma mansoni infection; in the early phase, Th1-related responses are induced, whereas during the late phase Th2 reactions dominate. Here, we describe unique T cell populations induced in the liver of mice during the period between Th1- and Th2-phases, which we term the transition phase. During this phase, varieties of immune cells including T lymphocytes increase in the liver. Subsets of CD4⁺ T cells exhibit unique cytokine production profiles, simultaneously producing both IFN-γ and IL-13 or both IFN-γ and IL-4. Furthermore, cells triply positive for IFN-γ, IL-13 and IL-4 also expand in the S. mansoni-infected liver. The induction of these unique cell populations does not occur in the spleen, indicating it is a phenomenon specific to the liver. In single hepatic CD4⁺ T cells showing the unique cytokine profiles, both T-bet and GATA-3 are expressed. Thus, our studies show that S. mansoni infection triggers the induction of hepatic T cell subsets with unique cytokine profiles.     

Periostin Links Mechanical Strain to Inflammation in Abdominal Aortic Aneurysm

Aims

Abdominal aortic aneurysms (AAAs) are characterized by chronic inflammation, which contributes to the pathological remodeling of the extracellular matrix. Although mechanical stress has been suggested to promote inflammation in AAA, the molecular mechanism remains uncertain. Periostin is a matricellular protein known to respond to mechanical strain. The aim of this study was to elucidate the role of periostin in mechanotransduction in the pathogenesis of AAA.

Methods and Results

We found significant increases in periostin protein levels in the walls of human AAA specimens. Tissue localization of periostin was associated with inflammatory cell infiltration and destruction of elastic fibers. We examined whether mechanical strain could stimulate periostin expression in cultured rat vascular smooth muscle cells. Cells subjected to 20% uniaxial cyclic strains showed significant increases in periostin protein expression, focal adhesion kinase (FAK) activation, and secretions of monocyte chemoattractant protein-1 (MCP-1) and the active form of matrix metalloproteinase (MMP)-2. These changes were largely abolished by a periostin-neutralizing antibody and by the FAK inhibitor, PF573228. Interestingly, inhibition of either periostin or FAK caused suppression of the other, indicating a positive feedback loop. In human AAA tissues in ex vivo culture, MCP-1 secretion was dramatically suppressed by PF573228. Moreover, in vivo, periaortic application of recombinant periostin in mice led to FAK activation and MCP-1 upregulation in the aortic walls, which resulted in marked cellular infiltration.

Conclusion

Our findings indicated that periostin plays an important role in mechanotransduction that maintains inflammation via FAK activation in AAA.     

Functions of beta2-adrenergic receptor in human periodontal ligament cells

Adrenergic receptors (ARs) are receptors of noradrenalin and adrenalin, of which there are nine different subtypes. In particular, β2 adrenergic receptor (β2-AR) is known to be related to the restoration and maintenance of homeostasis in bone and cardiac tissues; however, the functional role of signaling through β2-AR in periodontal ligament (PDL) tissue has not been fully examined. In this report, we investigated that β2-AR expression in PDL tissues and their features in PDL cells. β2-AR expressed in rat PDL tissues and human PDL cells (HPDLCs) derived from two different patients (HPDLCs-2G and -3S). Rat PDL tissue with occlusal loading showed high β2-AR expression, while its expression was downregulated in that without loading. In HPDLCs, β2-AR expression was increased exposed to stretch loading. The gene expression of PDL-related molecules was investigated in PDL clone cells (2-23 cells) overexpressing β2-AR. Their gene expression and intracellular cyclic adenosine monophosphate (cAMP) levels were also investigated in HPDLCs treated with a specific β2-AR agonist, fenoterol (FEN). Overexpression of β2-AR significantly promoted the gene expression of PDL-related molecules in 2 to 23 cells. FEN led to an upregulation in the expression of PDL-related molecules and increased intracellular cAMP levels in HPDLCs. In both HPDLCs, inhibition of cAMP signaling by using protein kinase A inhibitor suppressed the FEN-induced gene expression of α-smooth muscle actin. Our findings suggest that the occlusal force is important for β2-AR expression in PDL tissue and β2-AR is involved in fibroblastic differentiation and collagen synthesis of PDL cells. The signaling through β2-AR might be important for restoration and homeostasis of PDL tissue.     

Application of Nitrate Reductase for the Determination of Nitrate in Meat and Fishery Products

A rapid and specific method is described for the determination of nitrate in meat and fishery products.

Nitrate separated from foods by extraction with 1/50Ν sodium hydroxide and ultrafiltration was readily reduced to nitrite by the use of respiratory nitrate reductase (NR) from Escherichia coli K-12. The nitrite so obtained can be determined by the specific diazotation-coupling reaction method.

The use of an enzymatic reaction resulted in quantitative reduction of nitrate, and the method was relatively free of interferences. Recoveries of 10 and 100 ppm of nitrate from 5 samples of meat and fishery products ranged from 92.8 to 97.8% for 10 ppm and 97.8 to 99.4% for 100 ppm with a detection limit of 0.5 ppm.