Changes in plasma thyroid hormones, luteinizing hormone (LH), estradiol, progesterone and corticosterone of laying hens during a forced molt

1. Circulating concentrations of iodothyronines, luteinizing hormone(LH), estradiol(E2), progesterone and corticosterone were measured in hens before, during, and after a forced molt induced by fasting. 2. Corticosterone increased at the onset of molt, peaked at the maximal molt and returned to pre- and post-molt levels. LH, E2 and progesterone declined during the molt, and the decline was coincident with the cessation of egg production. 3. Thyroxine(T4), triiodothyronine (T3) and reverse triiodothyronine(rT3) increased during the molt. The increases of T4 and T3 were not abolished even if the forced molt was conducted in mild weather.     

Effect of polyamines on in vitro reconstitution of ribosomal subunits

The effect of polyamines on in vitro reconstitution of Escherichia coli 30S and 50S ribosomal subunits has been studied. Spermidine stimulated the reconstitution of 30S particles from 16S rRNA lacking the methyl groups on two neighboring adenines and total proteins of 30S subunits at least 1.6-fold. The reconstitution of 30S particles from normal 16S rRNA and total proteins of 30S subunits exhibited only slight spermidine stimulation. However, the optimal Mg2+ concentration of the reconstitution was decreased from 20 mM to 16 mM in the presence of 3 mM spermidine. In the absence of spermidine the assembly of 30S particles from normal 16S rRNA was more rapid than the assembly from 16S rRNA lacking the methyl groups on two neighboring adenines. The reconstitution of 50S particles from 23S and 5S rRNA and total proteins of 50S subunits was not influenced greatly by spermidine. Gel electrophoresis results, from reconstitution experiments of 30S particles from 16S rRNA lacking the methyl groups on two neighboring adenines and total proteins of 30S subunits, showed that the assembly of S1 and S9 proteins to 23S core particles was stimulated by spermidine during reconstitution. The relationship of polyamine effects on in vitro ribosome assembly from its constituents to in vivo ribosome assembly is discussed. The reconstitution of Bacillus subtilis 30S particles from 16S rRNA and total proteins of 30S subunits was also stimulated approximately 1.3-fold by 3 mM spermidine.     

Localization of alpha 2-adrenergic agonist sensitive area in the hypothalamus for growth hormone release in the rat

To determine the localization of the clonidine sensitive area responsible for GH release, a minute amount of the alpha 2-agonist (67 ng/0.2 microliter) was injected into the hypothalamus and vicinity of adult male conscious rats. The animals were chronically implanted with double metal cannulae fixed on the skull for clonidine microinjection and with silastic tubing into the right atria for collecting blood samples. Ten hr prior to the microinjection, alpha-methyl-p-tyrosine (250 mg/kg body weight) was intraperitoneally injected to prevent spontaneous pulsatile GH release. Localization of the microinjection was assessed by histological examination after the experiment. Clonidine microinjection into the amygdala nucleus had no effect on GH release, while the injection into the preoptic and anterior hypothalamic area (PO/AH) significantly stimulated GH release by causing it to begin 30 min earlier. However, the paraventricular nucleus, the dorsomedial nucleus, the lateral hypothalamus and the ventromedial hypothalamus areas did not respond to the injection, although the latter nucleus has been shown to be a specific locus sensitive to electrical stimulation of release. In the area from the posterior hypothalamus to the mammillary body, several injections stimulated GH release (6/15), but the stimulatory effect was statistically insignificant when comparison was made with the mean (+/- SE) for all 15 rats. These findings suggest that the alpha 2-agonist acts on the PO/AH to induce an increase in GH release in alpha-methyl-p-tyrosine-pretreated rats, probably mediating the inhibitory input to somatostatinergic neurons which reside in the periventricular nucleus of the PO/AH area.     

Significance of cathepsin B accumulation in synovial fluid of rheumatoid arthritis

We measured and compared the activities of various kinds of proteinases, such as cysteine, serine, aspartic, and metalloproteinases, in synovial fluids of 16 patients with rheumatoid arthritis (RA) and 18 patients with osteoarthritis (OA). More than 19-fold higher activity of cathepsin B and about 6-fold higher activity of prolylendopeptidase, compared to those of OA, were accumulated in RA fluid. Moreover, levels of cathepsins B and S using the corresponding sandwich enzyme immunoassays were statistically higher in RA fluid than those in OA. Significant amounts of 41-kDa and 35-kDa procathepsin L were detected in RA fluid using gelatin zymography, while 41-kDa enzyme alone was detected in OA. Cathepsin B in RA fluid could degrade collagen, and this degradation was suppressed by the addition of CA-074, a specific inhibitor of cathepsin B. Therefore, cathepsin B may participate in joint destruction of RA, and its inhibitor may be effective for RA care.     

Role of the putative membrane-bound endo-1,4-beta-glucanase KORRIGAN in cell elongation and cellulose synthesis in Arabidopsis thaliana

A temperature-sensitive, elongation-deficient mutant of Arabidopsis thaliana was isolated. At the non-permissive temperature of 31 degrees C, the mutation impaired tissue elongation; otherwise, tissue development was normal. Hypocotyl cells that had established cell walls at 21 degrees C under light-dark cycles ceased elongation and swelled when the mutant was shifted to 31 degrees C and darkness, indicating that the affected gene is essential for cell elongation. Analysis of the cell walls of mutant plants grown at 31 degrees C revealed that the cellulose content was reduced to 40% and the pectin content was increased to 162% of the corresponding values for the wild type grown at the same temperature. The increased amounts of pectin in the mutant were bound tightly to cellulose microfibrils. No change in the content of hemicellulose was apparent in the 31 degrees C-adapted mutant. Field emission-scanning electron microscopy suggested that the structure of cellulose bundles was affected by the mutation; X-ray diffraction, however, revealed no change in the crystallite size of cellulose microfibrils. The regeneration of cellulose microfibrils from naked mutant protoplasts was substantially delayed at 31 degrees C. The recessive mutation was mapped to chromosome V, and map-based cloning identified it as a single G-->A transition (resulting in a Gly(429)-->Arg substitution) in KORRIGAN, which encodes a putative membrane-bound endo-1,4-beta-glucanase. These results demonstrate that the product of this gene is required for cellulose synthesis.     

Rapamycin induces binding activity to the terminal oligopyrimidine tract of ribosomal protein mRNA in rats

Cathepsin G, elastase, and proteinase 3 are serine proteinases released by activated neutrophils. Cathepsin G can cleave angiotensinogen to release angiotensin II, but this activity has not been previously reported for elastase or proteinase 3. In this study we show that elastase and proteinase 3 can release angiotensin I from angiotensinogen and release angiotensin II from angiotensin I and angiotensinogen. The relative order of potency in releasing angiotensin II by the three proteinases at equivalent concentrations is cathepsin G > elastase > proteinase 3. When all three proteinases are used together, the release of angiotensin II is greater than the sum of the release when each proteinase is used individually. Cathepsin G and elastase can also degrade angiotensin II, reactions which might be important in regulating the activity of angiotensin II. The release and degradation of angiotensin II by the neutrophil proteinases are reactions which could play a role in the local inflammatory response and wound healing.