Preliminary study on the effect of rocking on activities of persons with severe mental and physical handicaps

In this preliminary observation, a group of seven mentally and physically handicapped persons of chronological ages ranging from 15.4 yr. to 26.8 yr. experienced 15 sec. of physical rocking. For the further analysis, the poststimulus periods were classified into either those when the subjects' spontaneous head, mouth, and body movements had increased from the prestimulus period or those decreased. The median heart rates recorded in the poststimulus period were not significantly different from those in the prestimulus period on trials on which there was an observable increase in the rates of spontaneous head, mouth, and body movements; however, the median heart rates decreased during those trials on which a decrease in the rates of the movements occurred. Since it is said that rocking heightens arousal of persons with mental and physical handicaps, it is suggested that spontaneously emitted, aimless head, mouth, and body movements attributed to low arousal were reduced by heightened arousal rather than by a decline in participants' activities.

Telomere shortening in the colonic mucosa of patients with ulcerative colitis

Telomere length in human somatic cells gradually decreases with the number of cell divisions and is regarded as a marker of somatic cell turnover. Mucosal cells of the affected colon show rapid turnover in individuals with active ulcerative colitis (UC). Telomere length was determined by Southern blot analysis of terminal restriction fragments (TRFs) from the colonic mucosa of 17 patients with UC in remission, two of whom showed dysplasia, and 17 control subjects without colitis. For each individual, mean TRF length was compared between rectal mucosa and unaffected cecal mucosa. The mean TRF length of the rectal mucosa was significantly less than that of cecal mucosa in UC patients (7.87 +/- 0.36kb versus 8.77 +/- 0.21 kb; P = 0.0015, Wilcoxon signed rank test), whereas no significant difference was detected in the control subjects. The extent of telomere shortening was 10.6 +/- 3.35% in UC patients, compared with 0.8 +/- 0.64% in noncolitis controls (P = 0.0024, Mann-Whitney U-test). Four UC patients, two of whom had dysplasia, showed telomere shortening of more than 20% in the rectal mucosa. These observations suggest that telomere shortening in the colonic mucosa of individuals with UC may represent the history of mucosal inflammation during disease of long duration, and that it may contribute to aneuploidy in UC.

Bilateral paraduodenal hernias: computed tomography and magnetic resonance imaging appearance

Paraduodenal hernias are rare congenital malformations. We report an unusual case of bilateral paraduodenal hernias diagnosed preoperatively by small bowel series, computed tomography (CT), and magnetic resonance imaging (MRI). Both CT and MRI are useful in the noninvasive diagnosis of paraduodenal hernias.

Fission yeast Ste9, a homolog of Hct1/Cdh1 and Fizzy-related, is a novel negative regulator of cell cycle progression during G1-phase

When proliferating fission yeast cells are exposed to nitrogen starvation, they initiate conjugation and differentiate into ascospores. Cell cycle arrest in the G1-phase is one of the prerequisites for cell differentiation, because conjugation occurs only in the pre-Start G1-phase. The role of ste9(+) in the cell cycle progression was investigated. Ste9 is a WD-repeat protein that is highly homologous to Hct1/Cdh1 and Fizzy-related. The ste9 mutants were sterile because they were defective in cell cycle arrest in the G1-phase upon starvation. Sterility was partially suppressed by the mutation in cig2 that encoded the major G1/S cyclin. Although cells lacking Ste9 function grow normally, the ste9 mutation was synthetically lethal with the wee1 mutation. In the double mutants of ste9 cdc10(ts), cells arrested in G1-phase at the restrictive temperature, but the level of mitotic cyclin (Cdc13) did not decrease. In these cells, abortive mitosis occurred from the pre-Start G1-phase. Overexpression of Ste9 decreased the Cdc13 protein level and the H1-histone kinase activity. In these cells, mitosis was inhibited and an extra round of DNA replication occurred. Ste9 regulates G1 progression possibly by controlling the amount of the mitotic cyclin in the G1-phase.

Precore wild-type DNA and immune complexes persist in chronic hepatitis B after seroconversion: no association between genome conversion and seroconversion

Precore hepatitis B virus (HBV) mutants may gradually prevail during or after seroconversion (SC) from hepatitis B e antigen (HBeAg) to hepatitis B e antigen antibody (anti-HBe) status in many chronic hepatitis B (CH-B) patients. However, patients with CH-B still produce anti-HBe more than several years after SC, and the relationship between SC and genome conversion in the precore region has not been clarified. Therefore, in patients with CH-B who had a sustained loss of HBeAg and complete remission of hepatitis after SC, the precore region was sequenced in paired serum samples from 1 year before SC to 3 years after SC. Mutant precore defective HBV DNA was found in only 6 (19%) of 31 CH-B patients who had a complete remission of hepatitis after SC. Mixed-type HBV DNA (precore wild-type and mutant-type) was found in 4 (13%) patients. Wild-type HBV DNA was found in 21 (68%) CH-B patients after SC. Longer-term follow-up of 11 CH-B patients indicated that 3 of 11 patients experienced precore genome conversion 2 to 3 years after SC. E-plus DNA or e-minus DNA was semiquantitated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assays before and after SC. E-plus DNA levels decreased from 10(5.56+/-1.58) to 10(2.45+/-1.61). Similarly, e-minus DNA levels declined from 10(4.25+/-1.56) to 10(1.86+/-1.37). By dot-blot assay, serum HBV DNA became negative soon after SC, as did serum HBeAg. In contrast, HBeAg-containing immune complexes were still detected after SC. Anti-HBe antibody was produced throughout SC and thereafter, as determined by a sensitive experimental assay. Therefore, we conclude that genome-conversion in the precore region is a separate event from HBeAg/anti-HBe seroconversion.

The Ste16 WD-repeat protein regulates cell-cycle progression under starvation through the Rum1 protein in Schizosaccharomyces pombe

The haploid cells of the fission yeast, Schizosaccharomyces pombe, are arrested in the G1-phase by nitrogen starvation and are committed to sexual reproduction (mating and sporulation). We isolated the sterile mutants which were defective in G1 arrest following nitrogen starvation. Genetic analysis of these mutants defined a single locus designated as ste16. The nucleotide sequence revealed that ste16+ encodes an 82-kDa protein containing eight WD40-repeats in its carboxy terminal half. The ste16 disruptant was viable, but arrested the cell cycle in the G2-phase after the nutritional down-shift. When transferred to fresh growth medium, the G2-arrested ste16Delta haploids resumed the mitotic cycle from the S-phase, resulting in diploidization. This diploidization phenomenon was completely suppressed by the null mutation of rum1 encoding the inhibitor of Cdc2 kinase. As the Rum1 protein level was remarkably elevated in the ste16Delta, the Ste16 protein negatively controls the Rum1 level. The loss of function of ste16 disturbs the cell-cycle progression and impairs the mechanism for the maintenance of ploidy.

Advanced glycation endproducts stimulate mitogen-activated protein kinase and proliferation in rabbit vascular smooth muscle cells

Advanced glycation end products of bovine serum albumin (AGEs-BSA) exhibited biphasic effects on the proliferation of cultured rabbit vascular smooth muscle cells (VSMCs) in terms of [3H]thymidine incorporation and cell number count; a stimulatory effect was observed at 1-10 micrograms/ml and an inhibitory effect at more than 20 micrograms/ml, while it inhibited [3H]thymidine incorporation even at 1-10 micrograms/ml in cultured bovine vascular endothelial cells (VECs). Transient activation of p42 mitogen-activated protein kinase (MAPK) with a peak at around 5 min and a subsequent sustained phase was induced by AGEs-BSA in VSMCs, but not in VECs. The dependence of MAPK activation on AGEs-BSA dose was correlated with that of VSMCs proliferation.

[Serum soluble CD8 and soluble interleukin-2-receptor levels during interferon therapy in chronic hepatitis C]

We examined the relationship between the changes of serum soluble CD8 (sCD8) and soluble interleukin-2 receptor (sIL-2R) levels and effectiveness of interferon (IFN) in patients with chronic hepatitis (CH) C. Changes in sCD8 levels were parallel with fluctuations of alanine aminotransferase (ALT) in CH patients during IFN treatment but decreases of sCD8 levels were slower than those of ALT. In IFN effective and ALT decreased patients sCD8 levels is also decreased. sIL-2R levels was increased transiently during administration of IFN in most cases. It was suggested that decrease in sCD8 levels is indicative of the effectiveness of IFN therapy.

[Effects of NSAIDs and PGE1 analogue on the permeability of human small intestine]

We studied permeability of human small intestine to clarify the following questions. 1) Does indomethacin increase intestinal permeability (IP)? 2) Does ornoprostil (PGE1 analogue) prevent the increased IP due to indomethacin? 3) Does acemetacin (pro-drug) increase IP? Eleven healthy volunteers were studied before and after ingestion of indomethacin, acemetacin, ornoprostil. After an overnight fast, they drank an isotonic solution containing 1.5 g rhamnose and 10.5 g lactulose. IP was estimated with lactulose/rhamnose percentage excretion in urine for 5 hours. An administration of indomethacin (75 mg) for one day increased IP significantly, and the coadministration of indomethacin and ornoprostil showed no significant change in IP compared with those of controls. Pro-drug administration did not increase IP. It is suggested that simultaneous administration of ornoprostil prevent the mucosal damage caused by indomethacin clinically, and that the mechanism of this increase IP is due to lack of mucosal prostaglandins on the small intestine.

Serum levels of vascular endothelial growth factor in patients with acute myocardial infarction undergoing reperfusion therapy

1. Vascular endothelial growth factor, a potent angiogenic mitogen, is known to be induced in response to ischaemia as well as being secreted from tumour cells. However, the precise mechanism of vascular endothelial growth factor release in acute myocardial infarction and the effects of coronary reperfusion on the circulating levels of vascular endothelial growth factor are still unknown. 2. Nineteen patients with acute myocardial infarction who underwent early reperfusion therapy were studied. Serum levels of vascular endothelial growth factor before reperfusion were markedly increased as compared with those in 19 healthy control subjects [252.4 +/- 158.1 pg/ml (mean +/- SD) compared with undetectable]. After reperfusion, the serum vascular endothelial growth factor levels rapidly returned almost completely to the normal control range. 4. These data strongly suggest that the serum level of vascular endothelial growth factor is one of the most sensitive indicators of myocardial ischaemia.

Purification and properties of a lipid transfer particle from Bombyx mori: comparison to the lipid transfer particle from Manduca sexta

A lipid transfer particle (LTP) was purified from the hemolymph of the silkworm Bombyx mori. Like other insect LTPs, the B. mori LTP is a very high density lipoprotein containing 21% lipid and three apoproteins of mass approximately 350 kDa, approximately 85 kDa, and approximately 60 kDa. B. mori LTP catalyzes the exchange of lipids between different density class lipoproteins found in adult hemolymph and between adult lipoproteins and vitellogenin. However, in no case was net lipid transfer observed. Manduca sexta LTP also catalyzed exchange of lipids, but not net transfer of lipids, between different density class lipoproteins found in adult hemolymph.

Cloning and characterization of two novel human cDNAs (NELL1 and NELL2) encoding proteins with six EGF-like repeats

From a human fetal-brain cDNA library we isolated two novel genes encoding peptides containing six EGF-like repeats. Both showed significant homologies with nel, a gene strongly expressed in neural tissues of chicken. The cDNAs, designated NELL1 (nel-like, type 1) and NELL2 (nel-like, type 2), contained open reading frames encoding 810 and 816 amino acids, respectively. NELL2 is strongly expressed in brain of adult and fetus but only weakly in fetal kidney. NELL1 and NELL2 were mapped by FISH to chromosomal bands 11p15.1-p15.2 and 12q13.11-q13.12, respectively.

[Detection of numerical chromosomal aberrations in hematopoietic malignancy by in situ hybridization on bone marrow aspirate paraffin sections]

We evaluated the usefulness of in situ hybridization (ISH) with chromosome specific DNA probe on paraffin sections of bone marrow aspirates. Twenty cases of hematopoietic malignancy and eight control cases of non-hematopoietic malignancy were examined with centromere-specific probes for chromosomes 8 and 17. In the eight control cases, the mean rates of cells with more than three hybridization signals were 1.13 (2SD = 1.90) for chromosome 8, and 0.88 (2SD = 2.25) for chromosome 17. The mean rates plus 2SD were 3.03 for chromosome 8, and 3.19 for chromosome 17. Therefore, we defined cases of more than 4.0% of cells showing more than three hybridization signals per nuclei as having a numerical abnormality (trisomy). We compared these results with conventional cytogenetic results by karyotype analysis. In twenty hematopoietic malignancy cases, three cases demonstrated trisomy 8 by ISH. Two cases also demonstrated this abnormality by karyotype analysis, but one case showed no abnormality by karyotype analysis. While trisomy 17 detected in one case that did not demonstrate numerical abnormality, only structural abnormality by karyotype analysis. The rate of discrepancy between results of ISH analysis and those of karyotype analysis was only 5% (2/40) for both chromosomes. In five cases, re-examinations were performed within three months. In one case, we could not obtain adequate material for karyotype analysis. However, this case showed trisomy 8 by ISH. Structural chromosomal abnormalities such as translocation or deletion could not be detected by this ISH analysis with centromere-specific probes. However, this method has the advantage result that we can perform retrospective assessments, do not need to culture cell, and can compare with pathological findings. Thus, we conclude that ISH analysis with paraffin sections of bone marrow aspirates will provide more useful information by combining ISH analysis and karyotype analysis.

Role of the proposed serpin-enzyme complex receptor recognition site in binding and internalization of thrombin-heparin cofactor II complexes by hepatocytes

Several serpin-enzyme complexes bind to a receptor on hepatocytes that mediates their endocytosis and lysosomal degradation. Joslin et al. (Joslin, G., Fallon, R. J., Bullock, J., Adams, S. P., and Perlmutter, D. H.(1991) J. Biol. Chem. 266, 11282-11288) proposed that a sequence near the C-terminal end of the serpin (e.g. FVFLM in alpha1-antitrypsin) binds to the serpin-enzyme complex receptor (SEC receptor). In experiments with synthetic peptides, they found that substitution of alanine at the fourth or fifth position in this sequence reduced the affinity of peptide binding to Hep G2 cells. To test the hypothesis that the corresponding sequence in heparin cofactor II (HCII), FLFLI (residues 456-460), mediates binding and uptake of the thrombin-HCII complex by Hep G2 cells, we constructed five recombinant HCII variants, F456A, L457A, F458A, L459A, and I460A. At 4 degrees C, the 125I-thrombin-HCII(native) complex bound reversibly to 0.6-2.6 x 10(5) sites per Hep G2 cell with a Kd of 19-32 nM. Binding was inhibited by excess unlabeled thrombin-HCII(native), thrombin-antithrombin, or elastase-alpha1-antitrypsin, but not by free HCII or thrombin, which is consistent with the reported specificity of the SEC receptor. However, complexes of thrombin with each of the HCII variants inhibited binding as effectively as the complex with native HCII. Competitive binding experiments with various concentrations of unlabeled thrombin-HCII(native) or thrombin-HCII(I460A) indicated that these complexes bind to Hep G2 cells with equal affinity. At 37 degrees C, complexes of 125I-thrombin with each of the five HCII variants were internalized and degraded at the same rate as the complex with native HCII. Our data suggest that the pentapeptide FLFLI in HCII is not involved in binding, internalization, and degradation of thrombin-HCII complexes by Hep G2 cells.

Secondary structure and Ca(2+)-binding property of the N-terminal half domain of calmodulin from yeast Saccharomyces cerevisiae as studied by NMR

Using two- and three-dimensional NMR techniques, 1H and main-chain 15N resonances of the N-terminal half domain of yeast calmodulin (YCM0-N) in the presence of Mg2+ and Ca2+ (Mg(2+)-and Ca(2+)-forms) were assigned. The secondary structures of YCM0-N in both forms were determined. The NOESY and 15N-edited NOESY spectra of YCM0-N in each form indicate that there is a hydrophobic core and that two Ca(2+)-binding loops are connected by a short antiparallel beta-sheet. There are four helices (A, B, C, and D named from the N-terminus) for YCM0-N in the Mg(2+)-form. The B-helix is, however, not formed in the Ca(2+)-form. The Ca(2+)-binding of YCM0-N was monitored by (1H,15N)-HSQC at various Ca2+ concentrations. The observed spectral changes as a function of Ca(2+)-concentration can not readily be grouped into a small number of classes; each residue shows individual spectral change. There is no apparent relationship between the spectral change and the type or location of the amino acid concerned.

Chimeras of yeast and chicken calmodulin demonstrate differences in activation mechanisms of target enzymes

Various chimeric proteins were constructed from yeast (Saccharomyces cerevisiae) and chicken calmodulin (CaM), and regions essential for target activation and responsible for the specific features of the yeast CaM were identified. The chimeric CaMs were designed so that each Ca2+ binding site of the yeast CaM was replaced in series from the C-terminus. Resulting CaM proteins showed Ca2+ binding properties inherent to the original Ca2+ binding site. Cooperative Ca2+ binding and a suitable rearrangement of the two EF-hand sites in each half-molecular domain were shown to be important for high-affinity interaction with CaM-dependent cyclic nucleotide phosphodiesterase (PDE). Residues in chicken CaM sequences 129-148 and 88-128, respectively, were required for low values of Kact (the concentration of CaM required for the half-maximal activation) in the activation of PDE and myosin light chain kinase (skMLCK and smMLCK). The difference in the structural requirements indicated different manners of the interaction. While PDE was activated to similar levels by different chimeras, the maximum activity (Vmax) given by chicken CaMs was not achieved by any chimeric CaMs in MLCKs. Residues in chicken CaM sequences 1-50 and 88-129, in addition to Ca2+ binding to the fourth site, were important for high values of Vmax of skMLCK. On the other hand, Met51 and residues in chicken CaM sequence 88-129 were critical for the high Vmax of smMLCK. These residues may work to form the active structure of the catalytic site of each MLCK, while simple binding of CaM seems sufficient to expose the active site of PDE.

Solution X-ray scattering data show structural differences between yeast and vertebrate calmodulin: implications for structure/function

We present here the first evidence, obtained by the use of solution X-ray scattering, of the solution structure of yeast calmodulin, a poor activator of vertebrate enzymes. The radius of gyration of yeast calmodulin decreased from 21.1 to 19.9 angstroms when excess Ca2+ ions were added. The profiles of the pair-distribution function suggested that yeast calmodulin without Ca2+ has a dumbbell-like shape which changes toward a rather asymmetric globular shape, from its dumbbell shape, by the binding of Ca2+. In the presence of a calmodulin binding peptide such as MLCK-22 (a synthetic peptide corresponding to residues 577-598 of skeletal myosin light chain kinase), the radius of gyration of yeast calmodulin decreased by 1.6 angstroms, and the molecular shape of it estimated from the profile of the pair-distribution function was globular but less compact than that of vertebrate calmodulin. These results for the structure of yeast calmodulin complexed with Ca2+ and with Ca(2+)-peptides are quite different from those of vertebrate calmodulin. Thus, the functional differences between yeast and vertebrate calmodulin which we reported previously [Matsuura, I., et al. (1993) J. Biol. Chem. 268, 13267-13273] have been interpreted on the basis of the structural differences between them. Moreover, the structural studies on chimeric proteins of chicken and yeast calmodulin suggest that Ca2+ binding at site IV is essential to form the full active dumbbell structure, which is characteristic of vertebrate-type calmodulin.

Effect of sodium nitroprusside on norepinephrine overflow and antidiuresis induced by stimulation of renal nerves in anesthetized dogs

To investigate the role of nitric oxide (NO) in the regulation of renal sympathetic nerve activity and renal function, we examined the effect of sodium nitroprusside (SNP), a NO donor, on renal actions induced by renal nerve stimulation (RNS) in anesthetized dogs, with or without blockade of an endogenous NO generation by NG-nitro-L-arginine (NOARG), a NO synthase inhibitor. Low-frequency RNS (0.5-2.0 Hz) enhanced the rate of norepinephrine secretion rate (NESR) from the kidney and decreased urine flow (UF), urinary excretion of sodium (U(Na)V), and fractional excretion of sodium (FENa, without affecting systemic and renal hemodynamics. The intrarenal arterial infusion of SNP, in a dose (1 mu g/kg/min) that does not affect renal hemodynamics and urine formation at the basal level, significantly attenuated the RNS-induced decreases in UF, UNa V and FENa. The intrarenal administration of NOARG (40 mu g/kg/min) elicited renal vasoconstriction and reduced urine formation. RNS during NOARG administration reduced renal blood flow (RBF) and glomerular filtration rate (GFR) and augmented RNS-induced reduction in urine formation. Simultaneously, NESR was markedly enhanced. The renal actions observed with NOARG administration during control and RNS periods were almost completely abolished by treatment with SNP. Therefore, we suggest that NO plays an important role in the regulation of renal function. Endogenous NO probably functions as an inhibitory modulator of renal noradrenergic neurotransmission at the prejunctional level.

Isolation and mapping of the human glycoprotein M6 gene (GPM6A) to 4q33-->q34

We have isolated a human cDNA that is highly homologous to the murine gene (Gpm6) encoding a membrane glycoprotein, M6. The human gene (GPM6A) contains an open reading frame of 834 nucleotides encoding a peptide of 278 amino acids. Northern-blot analysis revealed specific expression in human brain. We assigned the GPM6A locus to chromosome bands 4q33-->q34 by radiation hybrid mapping.

Cloning, expression pattern and mapping to Xq of NAP1L3, a gene encoding a peptide homologous to human and yeast nucleosome assembly proteins

From a human fetal brain cDNA library, we isolated a novel gene sharing significant homology with the genes of nucleosome assembly proteins (NAPs). This cDNA clone, designated NAP1L3 (nucleosome assembly protein 1-like 3), contained an open reading frame of 1518 nucleotides encoding 506 amino acids. Its predicted amino acid sequence showed 46% identity and 65% similarity with NAP1L. In its C-terminal half NAP1L3 contained several characteristic motifs strictly conserved with NAP1L and yeast NAP1, but the N-terminal half showed little conservation. Northern-blot analysis revealed strong expression of a 3.0-kb transcript in human adult brain and weak expression in heart. NAP1L3 was closely linked to a marker (DXS990) mapped to chromosome bands Xq21.3-->q22, where genes responsible for several X-linked mental retardation syndromes have been localized.

Molecular cloning of UBE2G, encoding a human skeletal muscle-specific ubiquitin-conjugating enzyme homologous to UBC7 of C. elegans

From a human fetal-brain cDNA library we isolated a novel ubiquitin-conjugating enzyme. The cDNA, designated UBE2G, contained an open reading frame of 510 nucleotides encoding 170 amino acids. The predicted peptide product showed 74% identity at the amino acid level with UBC7 of C. elegans, a high degree of homology with UBC7s of other species, and significant homologies with other subgroups of UBCs. Northern-blot analysis revealed strong expression of 4.4-kb, 2.4-kb, and 1.6-kb transcripts in skeletal muscle. Weak expression was observed in 15 other tissues examined. Radiation-hybrid mapping localized this cDNA to chromosome band lq42.

Population pharmacokinetics of theophylline. III. Premarketing study for a once-daily administered preparation

The population pharmacokinetic parameters for a once-daily administered preparation, Uniphyl were estimated from data collected in the premarketing clinical trial. Altogether, 2772 serum theophylline concentrations were obtained from 131 normal subjects and 306 patients suffering from chronic asthma or chronic obstructive pulmonary disease who participated in the phase I, II, and III clinical trials in Japan. The serum concentration profile was described by a linear one-compartment model with first-order absorption. The factors affecting the pharmacokinetics of this drug were examined by the likelihood ratio test using a nonlinear mixed effect model (NONMEM). The first-order absorption rate constant (Ka) for a 200-mg tablet in a fasting condition was obtained as 0.0773 (1/h), which was smaller than the elimination rate constant (0.168 1/h), indicating the flip-flop characteristic of this preparation. Food indigestion increased the Ka by 17% and the absorption lag time by 5-fold but did not affect the extent of absorption. The 400-mg tablet showed a Ka value 19%, smaller than the 200-mg tablet. Children not older than 15 years showed 58% longer absorption lag time. The inter-individual variability in Ka was 19%, suggesting small variability in the vivo release process. The total body clearance was related to hepatic function, smoking habits, and age. Furthermore, clearance decreased in association with the severity of illness. The findings obtained here are useful not only for the initial dosage adjustment for patients with a variety of backgrounds but also for doses individualization based on serum concentration monitoring with or without the Bayesian feedback method.

Enhancement of norepinephrine and angiotensin II-induced renal effects by NG-nitro-L-arginine, a nitric oxide synthase inhibitor

We investigated whether endogenous nitric oxide (NO) has a role as an inhibitory modulator of norepinephrine (NE)- and angiotensin II (Ang II)-induced renal effects in anesthetized dogs. Intrarenal arterial infusion of NE (100 ng/kg/min) or Ang II (10 ng/kg/min) decreased renal blood flow (RBF), glomerular filtration rate (GFR) and urine formation. The NE- or Ang II-induced renal effects were augmented by the intrarenal administration of a NO synthase inhibitor, NG-nitro-L-arginine (NOARG), at doses (10 and 40 micrograms/kg/min) which did not affect the mean arterial blood pressure and heart rate. The stimulating activity of NOARG on NE- or Ang II-induced renal effects were abolished by the simultaneous administration of L-arginine, a NO precursor. These findings suggest that endogenous NO, which is probably generated within the kidney, functions as an inhibitory modulator in NE- or Ang II-induced renal vasoconstriction and antidiuresis.