Involvement of sperm proteases in the binding of sperm to the vitelline envelope in Xenopus laevis.

Sperm binding to the vitelline envelope in dejellied Xenopus laevis eggs was effectively inhibited by inhibitors for trypsin (soybean trypsin inhibitor and p-toluenesulfonyl-L-lysine chloroethyl ketone) and aminopeptidase B (o-phenanthroline, bestatin, and arphamenine B). Likewise, synthetic 4-methylcoumaryl-7-amide (MCA) substrates (t-butoxycarbonyl-GlyArgArg-MCA, benzyloxycarbonyl-ArgArg-MCA, and Arg-MCA) inhibited binding. Consistently, when jellied eggs were inseminated in the presence of these substrates or inhibitors for proteases, fertilization was effectively blocked.

Bovine lactoferrin inhibits tumor-induced angiogenesis.

Recent studies have demonstrated that bovine lactoferrin (bLF) suppresses tumor growth and metastasis in the mouse and rat and moreover may inhibit angiogenesis. To determine whether angiogenesis inhibition might contribute to antitumor activity, we examined the influence of bLF on tumor-induced angiogenesis and endothelial cell functions as well as angiogenesis-related cytokine production. Bovine LF exhibited dose-dependent inhibition of angiogenesis on 4-6-day-old chick embryo chorioallantoic membranes (CAMs) that lack a mature immune response.

[Activity of DPP III in human cerebrospinal fluid derived from patients with pain].

Background: In the course of elucidating physiological roles of spinorphin, an endogenous regulator of enkephalin-degrading enzyme, we found that dipeptidyl peptidase III (DPP III) was contained in human cerebrospinal fluid (CSF). In this study, we examined the activity of DPP III in human CSF derived from patients with pain.

Methods: We used human CSF as specimen collected during operations under spinal anesthesia.

A novel hypoxia-dependent 2-nitroimidazole KIN-841 inhibits tumour-specific angiogenesis by blocking production of angiogenic factors.

Tumour angiogenesis is initiated by angiogenic factors that are produced in large amounts by hypoxic tumour cells. The inhibition of this step may lead to tumour-specific antiangiogenesis because normal tissues are not usually hypoxic. On the other hand, blocking a biological function of endothelial cells is known to result in angiogenic inhibition.

Spinorphin as an endogenous inhibitor of enkephalin-degrading enzymes: roles in pain and inflammation.

It is possible that enkephalins are involved in the pain-modulating mechanism in the spinal cord. Enkephalins, however, are short-lived, being rapidly degraded by various endogenous enzymes. Many substances that inhibit enkephalin-degradation have been investigated and it has been reported that some inhibitors (e.

Spinorphin, an endogenous inhibitor of enkephalin-degrading enzymes, potentiates leu-enkephalin-induced anti-allodynic and antinociceptive effects in mice.

Spinorphin (LVVYPWT) has been isolated from the bovine spinal cord as an endogenous inhibitor of enkephalin-degrading enzymes. It has been reported that spinorphin has an antinociceptive effect, inhibitory effect on contraction of smooth muscle and anti-inflammatory effect. In the present study, the effects of leu-enkephalin and spinorphin on allodynia and mechanical and thermal nociceptions were examined in vivo using mice.

Inhibition of angiogenesis by humulone, a bitter acid from beer hop.

On the basis of our previous finding that humulone, a bitter acid from beer hop extract, was a potent inhibitor of bone resorption and inhibited the catalytic activity of cyclooxygenase-2 (COX-2) and more potently the transcription of the COX-2 gene, we examined the effect of humulone on angiogenesis, using chick embryo chorioallantoic membranes (CAMs) and vascular endothelial and tumor cells. Humulone significantly prevented in vivo angiogenesis in CAM in a dose-dependent manner with an ED(50) of 1.5 microg/CAM.

Effects of spinorphin and tynorphin on synaptic transmission in rat hippocampal slices.

Spinorphin has been isolated from the bovine spinal cord as an endogenous inhibitor of enkephalin-degrading enzymes (aminopeptidase, dipeptidyl aminopeptidase III, angiotensin-converting enzyme and enkephalinase), and tynorphin has been synthesized as a more potent inhibitor of dipeptidyl aminopeptidase III. In this study, the effects of spinorphin and tynorphin on synaptic transmission were studied in rat isolated hippocampal slices. Field potentials were recorded from the CA1 region after stimulation of Schaffer collaterals.

Complete inhibition of purinoceptor agonist-induced nociception by spinorphin, but not by morphine.

We found that spinorphin, a novel neuropeptide showed analgesia in a different manner compared with morphine. By measuring flexor responses induced by the intraplanter injection of substances, the presence of three different types of sensory neurons were demonstrated. Although spinorphin completely blocked 2-metylthioadenosine (2-MeS ATP, a P2X(3) agonist)-induced responses, morphine did not.

Identification of dipeptidyl peptidase III in human neutrophils.

We have found activity of dipeptidyl peptidase (DPP) III, one of the most important enkephalin-degrading enzymes in the central nervous system, in human neutrophils. HPLC analysis of the peptide fragments produced by treatment of leucine-enkephalin with isolated neutrophils in the presence of inhibitors of other enkephalin-degrading enzymes revealed that the enzyme in human neutrophils cleaved dipeptides from the NH(2) terminus of leucine-enkephalin, suggesting the presence of DPPIII activity in human neutrophils. Using a specific synthesized substrate and proteinase inhibitors, it was found that the neutrophils have 19.

Characterization of tynorphin, a potent endogenous inhibitor of dipeptidyl peptidaseIII.

To find a more effective inhibitor than spinorphin (LVVYPWT), an endogenous factor derived from bovine spinal cord, we synthesized spinorphin analogues and assayed their inhibitory activity toward DPPIII among enkephalin-degrading enzymes. Tynorphin (VVYPW), an N-terminal and C-terminal truncated form of spinorphin, exhibited more potent inhibitory activity and an IC50 value of 0.086 +/- 0.

Inhibitory action of spinorphin, an endogenous regulator of enkephalin-degrading enzymes, on carrageenan-induced polymorphonuclear neutrophil accumulation in mouse air-pouches.

Whether spinorphin, an endogenous regulator of enkephalin-degrading enzymes, plays a role in an anti-inflammatory action was examined, using a mouse air-pouch assay as a model of acute inflammation. Repeated intravenous administration (6 times) of spinorphin every hour significantly suppressed carrageenan-induced polymorphonuclear neutrophil (PMN) accumulation, an indicator of inflammation (3.21+/-0.

[Changes in aminopeptidase N located on neutrophils derived from patients with chronic pain].

It is known that aminopeptidase N (APN) and neutral endopeptidase (NEP) in the central nervous system (CNS) regulate opioid peptides, leading to pain modulation. To examine whether these enzymes located on human neutrophils (PMNs) play a role in several modalities of pain, we measured the activity of these enzymes located on PMNs derived from patients with chronic pain and compared this with that of healthy volunteers. APN activity in the group of patients with chronic pain was significantly increased compared with that in group of healthy volunteers (4.

Inhibitory effects of spinorphin, a novel endogenous regulator, on chemotaxis, O2- generation, and exocytosis by N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated neutrophils.

To characterize the inflammatory effect of spinorphin, an endogenous peptide purified from bovine spinal cord, its effects on chemotaxis, O2- generation, and exocytosis by N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated human neutrophils (PMNs) in vitro were examined. At 10 microM, spinorphin significantly inhibited chemotaxis by FMLP-stimulated PMNs. Spinorphin at 100 microM also inhibited both O2- generation and exocytosis of beta-glucuronidase and collagenase by FMLP-stimulated PMNs.

[Study of a new endogenous inhibitor of enkephalin-degrading enzymes; pharmacological function and metabolism of spinorphin].

Spinorphin, a potent inhibitor of enkephalin degrading enzyme isolated from the bovine spinal cord, produces a dose-related inhibition of electrically evoked contractions of both MVD (mouse vas deferens) and GPI (guinea-pig ileum). Analgesic activity of Spinorphin was evaluated by the tail pinch method. The intraventricularly injected Spinorphin produced antinociceptive effect in a dose-dependent manner, in dose of 50-200 micrograms.

[Spinorphin, a new inhibitor of enkephalin-degrading enzymes derived from the bovine spinal cord].

We have isolated a potent inhibitor of enkephalin-degrading enzymes from the bovine spinal cord, and determined its amino-acid sequence and inhibitory activity against enkephalin-degrading enzymes. This new substance, isolated and identified from the bovine spinal cord, is composed of a heptapeptide (Leu-Val-Val-Tyr-Pro-Trp-Thr). The inhibitory activity (IC50) of this new substance against enkephalin-degrading enzymes, purified from monkey brain, are 3.

Isolation and identification of an endogenous inhibitor of enkephalin-degrading enzymes from bovine spinal cord.

We isolated a potent inhibitor of enkephalin-degrading enzymes from bovine spinal cord and determined its amino-acid sequence and inhibitory activity toward enkephalin-degrading enzymes. This new substance, designated spinorphin, is composed of a heptapeptide (Leu-Val-Val-Tyr-Pro-Trp-Thr). The inhibitory activity (IC50) of this new substance toward enkephalin-degrading enzymes, purified from monkey brain, was found to be 3.

Angiotensin III is a new chemoattractant for polymorphonuclear leukocytes.

To clarify the role of angiotensin III (ANGIII) in inflammation, we examined the effect of ANGIII on the chemotaxis of human polymorphonuclear neutrophils (PMNs). The elicitation of PMN chemotaxis by ANGIII was dose dependent with an optimum dose of 10(-10) M. The time course for ANGIII-elicited chemotaxis showed a maximal level at 90 min, but N-formyl-Met-Leu-Phe (FMLP) elicited a maximal level of chemotaxis at 60 min.

[Kyotorphin like substance in human cerebrospinal fluid of patients with persistent pain].

Kyotorphin is an analgesic neuropeptide isolated from the bovine brain in 1979. Further studies showed that kyotorphin produces an analgesia through an increased release of met-enkephalin in the brain and the spinal cord. We showed that it is also found in the human cerebrospinal fluid and the concentrations of kyotorphin in normal human CSF is 1.

Enkephalin-degrading aminopeptidase in the longitudinal muscle layer of guinea pig small intestine: its properties and action on neuropeptides.

A membrane-bound enkephalin-degrading aminopeptidase was purified from the longitudinal muscle layer of the guinea pig small intestine by four steps of column chromatography using L-tyrosine beta-naphthylamide. The molecular weight of the enzyme was estimated to be 105,000 by gel filtration. The maximum activity was observed between pH 6.

Enkephalin-binding protein in human blood.

An enkephalin-binding protein was found in human plasma and serum. The protein was partially purified by DEAE-cellulose column chromatography. The binding of [3H]leucine-enkephalin to this protein was competitively inhibited by unlabeled leucine- and methionine-enkephalin and various peptide hormones such as beta-endorphin and glucagon, but not by Leu-enkephalin-amide.

[A study of the leucine enkephalin like substance and enkephalin degrading enzyme activity in human cerebrospinal fluid].

Leucine enkephalin like substance (Leu-Enk) and enkephalin degrading enzyme activity (EDEA) in cerebrospinal fluid (CSF) of three patients suffering from pain were measured. As compared with control values before treatments, the values of Leu-Enk in CSF decreased, and those of EDEA increased in all the patients. After the treatment, two patients were fortunately cured of pain, and their two values returned to normal.

[Movement of plasma leu-enkephalin-like substance concentrations during pregnancy].

By the use of high performance liquid chromatography and a specific radioimmunoassay method combined with a new dialysis technique, plasma levels of leu-enkephalin were determined in 26 women who had become pregnant normally, some of whom were in 5 to 40 weeks gestation and the others were 3 days postpartum. Leu-enkephalin-like immunoactivity rose during 5-6 weeks gestation (982.0 +/- 388.

Protection of endogenous enkephalin degradation from peptidases in human serum by actinonin.

This paper describes a new method for detecting the endogenous enkephalin level in human serum without interference from serum peptidases and contaminating proteins. The method consists of a combination of addition of a peptidase inhibitor, actinonin to serum and dialysis. The activity of enkephalin degrading enzymes was completely abolished by actinonin.