Effects of polysorbates and Cremophor EL on vascular responses in rat aorta

The effects of Tween 20, Tween 80, and Cremophor EL, surface active agents which are used for dispersion of water-insoluble substances, on vascular responsiveness were investigated using rat aortic rings. In high concentrations all these agents produced persistent contractions in aortic rings independent of the presence of endothelium. These contractions were not influenced by inhibitors of known endogenous contractile mediators. Incubation with these agents caused a concentration-dependent inhibition of the endothelium-dependent relaxant responses to acetylcholine in intact precontracted aortic rings. Endothelium-independent relaxations produced by sodium nitroprusside were not inhibited, but rather potentiated in the presence of Tween 80 (10^–1 ml/l). On the other hand, Tween 80 inhibited the contractile effects of 5-hydroxytryptamine, phenylephrine, and bradykinin significantly. The data suggests that these substances affect both endothelial cells and vascular smooth muscle.     

龙虎山猕猴(Macaca mulatta)麻疹病毒感染的探讨

采用HI(血凝抑制试验)法,比较在不同生境中,龙虎山猕猴麻疹病毒抗体阳性率的差异:小群关养组的阳性率为90.9%;半野生猴组阳性率为28.3%;野生猴组阳性率为2.4%。不同性别及不同年龄猴麻疹病毒抗体阳性率没有显著性差异(P>0.01)。半野生猴组阳性率逐年递增。对建立无麻疹、B病毒等病毒感染繁殖种群提出初步意见。     

GABA-A-mediated gastrin release induced by baclofen in the isolated vascularly perfused rat stomach

Summary In order to investigate the role of peripheral GABA-B receptors, the effects of the putative GABA-B agonist baclofen on immunoreactive gastrin release from an isolated vascularly perfused rat stomach preparation were examined. The vascular infusion of baclofen at graded concentrations induced a dose-dependent increase in gastrin release; this was unaffected by the GABA-B antagonist delta-aminovaleric acid, but was fully prevented by the selective GABA-A antagonist bicuculline as well as by atropine or tetrodotoxin. These results suggest that the stimulant effects of baclofen are mediated by nervous cholinergic structures, associated with GABA-A receptors, and indicate that this GABA-B agonist must be regarded as a partial agonist of peripheral GABA-A receptors.     

Aberrant DNA methylation patterns in cultured mouse embryos

Mouse early embryos undergo genome-wide demethylation and remethylation events during pre-implantation development. Abnormal methylation reprogramming is thought to be associated with development arrest. Using immunofluorescence staining with an antibody against 5-methylcytosine (MeC), we examined the genome methylation patterns of mouse embryos cultured in vitro. The results did not show the difference in staining patterns between development-blocked two-cell embryos that cultured in vitro and the two-cell embryos that were freshly collected from the donor mice. But in vitro-arrested morulae displayed a strong positive staining when compared to the morulae freshly collected from the donor mice. At the blastocyst stage, although most embryos showed the expected methylation patterns, with highly stained inner cell mass (ICM) and weekly stained trophectoderm (TE), a proportion of embryos were dimly stained in both ICM and TE. These results indicated that the methylation profile of the embryos could be changed by culturing in vitro when the embryos were in the transition from morulae to blastocyst.     

Evidence for no relationship of the pineal activity with the neonatal shrinkage of Leydig cells in the rat

Summary The collective volume of Leydig cells in prenatally pinealectomized newborn rats declined as sharply as in intact newborn rats. Also, the collective volume in pups born in the dark declined in a fashion similar to that in pups born in the light. The results indicate that neither the pineal gland nor the light is responsible for the neonatal shrinkage of Leydig cells.This study was supported in part by a Grant-in Aid for Scientific Research (No. 548067) from the Ministry of Education, Science and Culture of Japan.     

Cholera toxin B-subunit incorporation into synaptic vesicles of the neuromuscular junction of the rat

Summary The B-subunit of cholera toxin, a nontoxic macromolecule which binds specifically to GM1 ganglioside, was conjugated to colloidal gold and injected into skeletal muscle of the rat. It was taken up rapidly in vesicles in the terminal axons at the neuromuscular junctions. Injection of albumin-colloidal gold conjugates resulted in an insignificant uptake. The results indicate that uptake of extracellular macromolecules into the terminal axon of the neuromuscular junction may be greatly enhanced by binding to gangliosides at the presynaptic membrane, and that it may occur without association with vesicular recycling related to transmitter release.The study was supported by grants from the Swedish Medical Research Council (proj. No. 07122).—Part of this study was performed at INSERM U-153, Paris, headed by Dr M. Fardeau.     

Super-high sensitivity systems for detection and spectral analysis of ultraweak photon emission from biological cell cells and tissues

Summary In this paper we summarize and discuss the modern technology and systems, studied and established by our research group, for performing the detection and special analysis incorporated with the super-high senstivity photon counting method for the study of ultraweak photon emission; for example, extra-weak bioluminescence and chemiluminescence from living cells and tissues, closely related to biochemical and biophysical processes and activities. An excellent sensitivity of the basic photon counting system, making it possible to achieve count rates in the very low range of one photoelectron per second to one per minute, allowed us to carry out in vivo as well as in vitro measurements, and analyses of ultraweak bioluminescence and chemiluminescence. Recent results concerning ultraweak photon emission from blood samples and organ homogenates of rats are presented and reviewed as one of the interesting and valuable applications of our modern technology for studying ultraweak cell and tissue radiation.     

Carbohydrate interference of complement-dependent cell lysis

Summary The antibody-mediated cytotoxicity of three autoreactive sera, an allogeneic hyperimmune serum and a xenogeneic hyperimmune serum was abrogated by the presence of either glucosamine, galactosamine, lactulose or lactose. This inhibition could be overcome in a dose-dependent fashion by increasing the amount of complement in the cytotoxicity assay, but not by increasing the amount of antibody. Furthermore, the inhibition was specific for these sugars in that isomers and N-acetylated derivatives were not inhibitory. The results suggest that these sugars directly blocked events of the complement cascade.     

Pineal function cannot prevent the occurrence of castration cells in male rats

Summary The relationship between the pineal gland and the pituitary gland was investigated in male rats. The results indicate that the hypothalamo-adenohypophysial-gonadal axis is affected by the pineal gland, but the appearance of castration cells following gonal ablation may be only slightly modified by alterations in pineal gland function.