High-performance liquid chromatographic resolution of synthetic opiate and "anti-opiate" peptides from human plasma

An assay system using reversed-phase high-performance liquid chromatographic (HPLC) resolution of synthetic anti-opioid peptides (AOPs) and opioid peptides (OPs) was developed. Samples were diluted with trifluoroacetic acid, loaded onto Sep-Pak C18 cartridges, eluted, dried, and redissolved in ethanol-acetic acid-water. Retention-time consistency was established, and high levels of synthetic AOP and OP recovery, generally higher than 80%, were achieved. In a single HPLC run synthetic enkephalins, dynorphins, and beta-endorphins were separated even when extracted from human plasma using a volatile mobile phase which yielded fractions totally compatible with quantitation by radioimmunoassay. Combining the resolution of HPLC with the sensitivity of radioimmunoassay (RIA) may facilitate simultaneous measurement of numerous neuropeptides in body fluids such as plasma and cerebrospinal fluid.

[Analysis of poisonous trace elements in huangwu gongmitai]

A comparative study was made on the dissolved amount of poisonous trace elements mercury and arsenic contained in hydrargyri subchloridum and realgar of gynecological suppository in artificially simulated vaginal acid-base liquid with that contained in hydrargyri subchloridum and realgar in artificial gastric juice stipulated in Pharmacopeia of China. The result shows that the dissolved amount of mercury and arsenic contained in the suppository is much smaller than that stipulated in Pharmacopeia for oral administration.

Elevation of transforming growth factor-alpha mRNA and protein expression by diverse tumor promoters in SENCAR mouse epidermis

The study presented here was designed to further investigate the role of transforming growth factor-alpha (TGF alpha) in skin tumor promotion by examining the ability of 12-O-tetradecanoylphorbol-13-acetate (TPA) and several non-phorbol ester promoters to alter TGF alpha mRNA and protein levels in mouse epidermis. Total RNA was isolated from SENCAR mouse epidermis at various times after single topical treatments with TPA (3.4 nmol), chrysarobin (220 nmol), okadaic acid (2.5 nmol), and thapsigargin (8.5 nmol). Northern analyses of these isolated RNA samples revealed that all four tumor promoters transiently elevated TGF alpha mRNA levels. Whereas TPA, okadaic acid, and thapsigarin elevated TGF alpha mRNA levels over similar time courses (peak at 4-8 h), chrysarobin elevated TGF alpha mRNA levels with a markedly delayed time course (peak at 24-48 h). More detailed studies with TPA also revealed that multiple treatments (four over a 2-wk period) transiently elevated TGF alpha mRNA in both the epidermis and the dermis. The time courses for changes in TGF alpha mRNA after multiple TPA treatments were similar for both tissues. To facilitate studies of altered TGF alpha mRNA expression in mouse epidermis and possibly other mouse tissues, a semiquantitative reverse transcriptase-polymerase chain reaction method was developed. This method faithfully revealed changes in TGF alpha mRNA levels with all four tumor-promoting agents similar to those determined by northern blot analyses. Immunofluorescence analysis of frozen sections from promoter-treated skin revealed elevated TGF alpha protein levels in both epidermis and dermis, although staining was most intense in the epidermal layer. Immunofluorescence analysis of epidermal hyperplasia adjacent to a full-thickness wound also demonstrated significant epidermal TGF alpha staining. Collectively, these results indicate that mechanistically diverse tumor promoter stimuli elevate TGF alpha mRNA and protein in SENCAR mouse epidermis. Elevated levels of TGF alpha may play an essential role in mitogenic stimulation during tumor promotion by diverse promoting stimuli.

Suppression of human melanoma metastasis by introduction of chromosome 6 may be partially due to inhibition of motility, but not to inhibition of invasion

Active cellular motility and invasion play essential roles in metastasis. Introduction of normal, neo-tagged human chromosome 6 (neo6) into highly metastatic human melanoma cell line C8161 results in complete suppression of metastasis in vivo. To understand the mechanism by which metastasis was inhibited in neo6/C8161 hybrids, two in vitro assays, pseudopod protrusion and Membrane Invasion Culture System, were used to measure motility and invasion, respectively. neo6/C8161 hybrids are much less motile although they remained invasive, indicating that a metastasis-suppressor gene(s) on human chromosome 6 may regulate cellular motility, thereby inhibiting metastasis.

Characterisation of an ATP receptor mediating mitogenesis in vascular smooth muscle cells

Adenosine triphosphate (ATP), a co-transmitter in sympathetic nerves and released from platelets, has recently been shown to stimulate growth of vascular smooth muscle cells. It might therefore contribute to the development of vascular hypertrophy seen in hypertension and atherosclerosis. We aimed at characterising the receptor mediating this mitogenic effect in rat aorta smooth muscle cells. The potency of agonists indicates a P2 purinoceptor since ATP > or = ADP >> AMP, adenosine. The P2x-receptor subtype, which is responsible for ATP induced vasoconstriction in rat aorta, does not mediate the mitogenic effect since alpha, beta-methyleneATP had no effect and beta, gamma-methyleneATP had lower potency than ATP. The P2Y-receptor subtype was excluded since the selective agonist 2-methylthioATP had weak effect with lower potency than ATP. When we studied the involvement of other nucleotides similar effects were seen of the purines ATP, GTP and ITP; also the pyrimidine UTP had powerful mitogenic effects (Emax = 52% of ATP) with similar potency. Nucleotides with fewer phosphate groups showed a stepwise fall in mitogenic effect. This indicates involvement of a nucleotide-receptor (P2U). Ap4A were of equal potency and effect as ATP. There was strong correlation between the mitogenic effects of the nucleotides and analogues with both 45Ca(2+)-influx and inositol phosphate (IP) production, indicating that they may participate in mediating the mitogenic response. This is the first study describing the potencies for the mitogenic effects of the selective ATP-analogues and other nucleotides in vascular smooth muscle cells. The receptor characterisation indicates a nucleotide-receptor similar to the receptor which stimulates 45Ca(2+)-influx and inositol phosphate-formation in rat aorta smooth muscle cells. Substances related to ATP such as GTP, ITP, UTP and Ap4A which also can be released extracellularly in vivo stimulate mitogenesis of rat aorta smooth muscle cells through the same receptor.

Effect of cardiomyoplasty on systolic and diastolic function

Although cardiomyoplasty has become a recognized treatment for end-stage heart failure, the effects of this procedure on systolic and diastolic function are still unclear. To determine the effects of paced and non-paced latissimus dorsi cardiomyoplasty on systolic and diastolic function, the maximal elastance of the left ventricle (Emax), stroke volume, preload recruitable stroke work and diastolic compliance were measured in an experimental heart failure model. Collateral blood vessels to the latissimus dorsi were ligated 2 weeks before cardiomyoplasty in order to reduce the risk of ischemic injury. Histological examination of muscle biopsies confirmed that the two-stage procedure preserved normal muscle architecture. The non-paced cardiomyoplasty wrap adversely affected both systolic and diastolic function. Paced Latissimus Dorsi during heart failure improved systolic function but had no measurable effect on diastolic function.

CONCLUSIONS

1. Non-paced, or unstimulated, latissimus dorsi cardiomyoplasty acutely impairs cardiac function. 2. Delayed cardiomyoplasty, 2 weeks after collateral ligation, prevents ischemic injury to the muscle flap.

Alpha-trinositol blocks the inhibitory effects of NPY on dilatation to forskolin but not the adenylyl cyclase activity induced by NPY or forskolin in guinea-pig cerebral vessels

There is much data showing correlation between forskolin-induced relaxation and production of cyclic AMP. But are these processes coupled or two phenomena occurring in parallel? This question was studied in guinea-pig cerebral vessels by using NPY as a strong inhibitor and alpha-trinositol as its antagonist. The basal cyclic AMP content of cerebral vessel segments in the control group was 670 +/- 53 fmol/mg wet weight (w.w.). Forskolin (10(-7), 3 x 10(-7) and 10(-6) M) increased the formation of cyclic AMP to 738 +/- 86 (ns), 699 +/- 81 (ns) and 1158 +/- 132 fmol/mg w.w. (p < 0.05), respectively. alpha-trinositol (10(-8)-10(-6) M) neither reduced the formation of cyclic AMP compared to basal cyclic AMP levels nor affected the forskolin-stimulated increase of cyclic AMP (p > 0.05). On the other hand, NPY (10(-7) M) not only decreased basal formation of cyclic AMP (p < 0.05) but also attenuated the forskolin-stimulated increase of cyclic AMP (p < 0.005). The inhibitory effects of NPY on both basal levels of cyclic AMP and forskolin-induced increase of cyclic AMP were not reversed by the application of alpha-trinositol (10(-8)-10(-6) M). In studies on vasomotor responses, forskolin (10(-9)-10(-5) M) induced a concentration-dependent relaxation of precontracted guinea-pig basilar arteries. NPY (10(-7) M) shifted the forskolin-induced relaxation of the basilar arteries towards higher forskolin concentrations. This inhibitory effect of NPY was reversed by alpha-trinositol (10(-6) M). We conclude that 1) NPY decreases basal and forskolin-stimulated cyclic AMP levels; 2) alpha-trinositol neither reverses the inhibitory effect of NPY on nor modulates basal or forskolin-stimulated cyclic AMP levels; 3) However, the antagonistic effect of NPY on forskolin-induced relaxation is significantly reversed by administration of alpha-trinositol. This demonstrates a dissociation of the dilator effects of forskolin and its generation of cyclic AMP.

[Biodistribution and metabolism of 3H-gastrodigenin and 3H-gastrodin in mice]

The biodistribution and metabolism of 3H-gastrodigenin and 3H-gastrodin after intravenous injection were studied by the detection of their radioactivity in mice tissue; the radioactive elements of mice tissue extracts after intravenous injection of 3H-gastrodin were analyzed with thin-layer chromatography (TLC). The results demonstrated that gastrodin could penetrate through the blood-brain barrier into the brain, and it was rapidly decomposed into the gastrodigenin in brain, liver and blood. Then gastrodigenin preserved in brain and mediated its pharmacological inhibitive effects on the central nervous system. Most of the gastrodigenin and gastrodin were excreted by the kidney. The findings also suggested that gastrodin might exist in the enterohepatic circulation.

alpha-Trinositol blocks neuropeptide Y-induced inositolphosphate formation in cerebral vessels

Neuropeptide Y (NPY) induces contraction of guinea-pig basilar arteries via activation of Y1 receptors. This contraction is blocked by D-myo-inositol-1,2,6-triphosphate (alpha-trinositol). Previous binding studies have shown that alpha-trinositol has no effect at Y1 or Y2 binding sites thus the antagonistic effect should occur at the level of a second messenger. We have examined the effects of NPY on the formation of inositol phosphates (IP) and have looked for an antagonistic effect of alpha-trinositol. NPY (10(-9)-3 x 10-(-7) M) induced strong concentration-dependent contraction of basilar arteries from young guinea-pigs (weight 200-250 g) (Emax: 76.4 +/- 11.1%) but not of arteries from old guinea-pigs (weight > 500 g) (Emax: 2.8 +/- 1.5%). [Pro34]NPY and PYY induced contraction of similar magnitude and potency, whereas NPY13-36 had only a weak effect. This demonstrates an effect via the Y1 type of NPY receptor. The contraction induced by NPY was blocked by alpha-trinositol (p < 0.05). LiCI (2 x 10-4) M), used to inhibit IP breakdown, had no effect on the contraction induced by NPY. NPY (10(-10)-10(-8) M) increased the formation of IP in cerebral vessels from young guinea-pigs from 357 +/- 48 cpm/mg w.w. to 900 +/- 233 cpm/mg w.w. However, there was no alteration in IP formation in cerebral vessels from old guinea-pigs (NPY 10(-9)-10(-7) M). In the presence of alpha-trinositol (10(-8)-10(-6) M) the NPY induced stimulation of IP formation was totally abolished.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of albendazole on Ancylostoma caninum larvae migrating in the muscles of mice

When mice inoculated with 1,000 third-stage larvae of Ancylostoma caninum for 1 week were treated intragastrically (ig) with albendazole (Alb) 75, 150 or 300 mg/kg.d for 3 days, the mean larva numbers collected from the muscles of each group were 2.7 +/- 1.7, 2.0 +/- 1.5 and 1.0 +/- 1.0, respectively, being much less than that 205 +/- 68 of the control group. In mice treated ig with Alb 150 mg/kg.d for 3 days, the concentrations of Alb and its effective metabolite, albendazole sulfoxide (AlbSO), were determined in plasma and the muscles at different intervals after the last medication using high performance liquid chromatography. The results showed that only low concentrations of Alb were detected in both plasma and the muscles. However, higher concentrations of AlbSO were found not only in the plasma (5.4-10.5 micrograms/ml), but also in the muscles (2.2-4.6 micrograms/g). The higher contents of AlbSO in the muscles would be helpful for killing the Ancylostoma larvae migrating in the muscles of mice.

Does the gender of the child affect acceptance of the one-child certificate? The case of Shaanxi province, China

The author investigates the impact of gender on both acceptance of the one-child certificate and contraceptive use in Shaanxi province, China. "We found a weak association...in both the cross-classification and multiple classification analyses of the 1988 Two-per-Thousand Survey data. However,...[son preference] remains a clear tendency in rural areas, but the low proportion of the one-child certificate acceptors reflects the existence of stronger preferences for larger family size and specific sex composition.... By contrast, the high percentage of urban acceptors of the one-child certificate, regardless of the gender of the child, implies that son preference has decreased in urban areas of Shaanxi Province."

Characterization of endothelin-A receptors in the cerebral circulation

Endothelin-1 (ET-1), a 21-amino acid peptide produced by the vascular endothelium, mediates contraction. In the present study we demonstrate that both ET-1 (Emax: 238 +/- 29% of potassium contraction) and ET-2 (Emax: 231 +/- 36%) produce strong concentration-dependent contractions of circular segments of guinea-pig middle cerebral artery, whereas ET-3 has only weak effects (Emax: 32 +/- 13%). FR 139317 (10(-6) M), a selective endothelinA (ETA) receptor antagonist, shifted the ET-1 response curve to the right (pD2:7.86 +/- 0.09 with and 8.76 +/- 0.09 without the antagonist) in a competitive manner (pA2 = 6.83). These findings are the first to show the presence of ETA receptors in cerebral vessels.

[The antigastroulcerative activity of beta-sitosterol-beta-D-glucoside and its aglycone in rats]

Beta-sitosterol-beta-D-glucoside and its aglycone (the major constituent of the seed oil of Hippophae rhamnoides L.) were investigated for their antigastroulcerative activity in rats. Two experimental gastric ulcer models were selected: chronic acetic acid-induced ulcers and cold stress-induced ulcers. Both the glucoside and its aglycone showed antiulcerative activity in chronic acetic acid-induced gastric ulcer models, and their effects were at least comparable to the effects of wishupin in combination with cimetidine. The effect of aglycone appears better than the glucoside's. Glucoside also showed visibly antiulcerative effects on cold stress-induced ulcers, but wishupin combined with cimetidine did not have such effects.