Development and genetic mapping of 127 new microsatellite markers in barley

To enhance the marker density of existing genetic maps of barley ( Hordeum vulgare L.), a new set of microsatellite markers containing dinucleotide motifs was developed from genomic clones. Out of 254 primer pairs tested, a total of 167 primer pairs were classifed as functional in a panel of six barley cultivars and three H. spontaneum accessions, and of those, 127 primer pairs resulting in 133 loci were either mapped or located onto chromosomes. The polymorphism information content (PIC) ranged from 0.05 to 0.94 with an average of 0.60. The number of alleles per locus varied from 1 to 9. On average, 3.9 alleles per primer pair were observed. The RFLP frameworks of two previously published linkage maps were used to locate a total of 115 new microsatellite loci on at least one mapping population. The chromosomal assignment of 48 mapped loci was corroborated on a set of wheat-barley chromosome addition lines; 18 additional loci which were not polymorphic in the mapping populations were assigned to chromosomes by this method. The microsatellites were located on all seven linkage groups with four significant clusters in the centromeric regions of 2H, 3H, 6H and 7H. These newly developed microsatellites improve the density of existing barley microsatellite maps and can be used in genetic studies and breeding research.

Osteogenic potential of five different recombinant human bone morphogenetic protein adenoviral vectors in the rat

Bone morphogenetic protein (BMP) adenoviral vectors for the induction of osteogenesis are being developed for the treatment of bone pathology. However, it is still unknown which BMP adenoviral vector has the highest potential to stimulate bone formation in vivo. In this study, the osteogenic activities of recombinant human BMP-2, BMP-4, BMP-6, BMP-7, and BMP-9 adenoviruses were compared in vitro, in athymic nude rats, and in Sprague-Dawley rats. In vitro osteogenic activity was assessed by measuring the alkaline phosphatase activity in C2C12 cells transduced by the various BMP vectors. The alkaline phosphatase activity induced by 2 x 10(5) PFU/well of BMP viral vector was 4890 x 10(-12) U/well for ADCMVBMP-9, 302 x 10(-12) U/well for ADCMVBMP-4, 220 x 10(-12) U/well for ADCMVBMP-6, 45 x 10(-12) U/well for ADCMVBMP-2, and 0.43 x 10(-12) U/well for ADCMVBMP-7. The average volume of new bone induced by 10(7) PFU of BMP vector in athymic nude rats was 0.37+/-0.03 cm(3) for ADCMVBMP-2, 0.89+/-0.07 cm(3) for ADCMVBMP-4, 1.02+/-0.07 cm(3) for ADCMVBMP-6, 0.24+/-0.05 cm(3) for ADCMVBMP-7, and 0.63+/-0.07 cm(3) for ADCMVBMP-9. In immunocompetent Sprague-Dawley rats, no bone formation was demonstrated in the ADCMVBMP-2, ADCMVBMP-4, and ADCMVBMP-7 groups. ADCMVBMP-6 at a viral dose of 10(8) PFU induced 0.10+/-0.03 cm(3) of new bone, whereas ADCMVBMP-9 at a lower viral dose of 10(7) PFU induced more bone, with an average volume of 0.29+/-0.01 cm(3).

[Study on the triboluminescent property of ZnS:Mn]

Triboluminescence (TL) is the emission of light induced by the application of mechanical energy to a solid. It links the spectroscopic, structural, mechanical, and electrical properties of solids. Here, materials of ZnS doped with various contents of Mn2+ were investigated. It was shown that they all have favorable triboluminescent property. The effects of the content of Mn2+, the sintering temperature and time on the luminescent property of ZnS:Mn were discussed. It was found the ZnS doped with 1.2% Mn2+ exhibited the strongest TL intensity among the materials investigated. The growth conditions were obtained through experiments, and ZnS:Mn with highly efficient triboluminescence was prepared. The mechanism of triboluminescence is proposed as follows: the electrons are excited from ground state to excited state by mechanic energy, then recombines with holes and give lights. The broad range of exciting energy may contribute to the high triboluminescent efficiency.

[Study on the deteriorating course of fresh milk by laser-induced fluorescence spectra]

Along with the development of living standard, people's demand for food quality and food hygiene also rises. People demand food not only with rich nutrition, inexpensive price, but also with safety. So food hygiene test is paid common attention of society. Milk is a nourishing food and is loved by people. Sour milk goods from milk is also in great demand. But nourishing foods are good for growing many microbes. Fresh milk and sour milk are easy contaminated by microbes and go bad. Laser-induced fluorescence (LIF) technology is an important part of modern optics. It is broadly applied in biomedicine, diagnostics, test of food hygiene, environment protecting, owing to its high sensitivity, high speed, automation, untouched testing. In this paper, we attempted to LIF technology to test milk food quality. We used the third harmonics pulsed Nd:YAG laser (355 nm) as the exciting source, and a multi-track spectrometer as the detector and measured the intensities of apply LIF of fresh milk and sour milk during their deteriorating course. Test system and test method are introduced, fluorescence spectra of deteriorating course are also attached. The test result makes clear that there are close connection between deteriorating course and fluorescence spectra.

A light and electron microscopic study of ectopic tendon and ligament formation induced by bone morphogenetic protein-13 adenoviral gene therapy

OBJECT

Bone morphogenetic proteins (BMPs) are involved in the growth and development of many tissues, but it is their role in skeletal development and their unique ability to induce ectopic and orthotopic osteogenesis that have attracted the greatest interest. Expression of the BMP-13 gene is predominantly localized to hypertrophic chondrocytes in regions of endochondral bone formation during development, as well as in mature articular cartilage in the adult. In addition, the application of BMP-13 on a collagen carrier induces neotendon/neoligament formation when delivered subcutaneously or intramuscularly in rodents. The aim of the present study was to determine the histological and ultrastructural changes that occur after the intramuscular injection of a first-generation BMP-13 adenoviral vector.

METHODS

Athymic nude rats were injected with 3.75 x 10(10) plaque-forming units of adenovirus (Ad)-BMP-13 or Ad-beta-galactosidase in the thigh musculature, and the region was examined using light and electron microscopy at various time points between 2 days and 100 days postinjection. As early as 2 days after injection of Ad-BMP-13, progenitor cells were observed infiltrating between the transduced muscle fibers. These cells subsequently proliferated, differentiated, and secreted large amounts of collagenous extracellular matrix. By 100 days postinjection, the treated tissue displayed the histological and ultrastructural appearance of neotendon/neoligament, which was clearly demarcated from the surrounding muscle. Small foci of bone and fibrocartilage were also seen within the treated tissue. A short-term bromodeoxyuridine study also demonstrated rapid mesenchymal cell proliferation at the Ad-BMP-13 injection site as early as 48 hours postinjection. At all time points, the control AD-beta-gal injection sites were found to contain only normal muscle, without evidence of inflammation or mesenchymal cell proliferation.

CONCLUSIONS

The results of this study indicate that in the future the use of the BMP-13 gene may have therapeutic utility for the healing of tendon and ligament tears and avulsion injuries.

[The study of skeletal mechanics of anterior crossbite evaluated with SN length]

OBJECTIVE

To study the stability of SN (anterior cranial base) length and the ability to evaluate upper lower jaws, and study the inner skeletal structure mechanism.

METHODS

Interrelated angles, SN length, maxillary and mandible length were measured, the ratios between SN and maxillary and mandible length were compared with normal standard data, the data between mixed and permanent dentition groups were compared.

RESULTS

No significant difference was found on SN length between anterior crossbite patients and normal sample. Significant difference was found between crossbite and normal data on the ratio of SN and maxillary length and mandible length. Based on evaluation of SN length, the crossbite can be divided into three types of skeletal structures including normal maxilla and longer mandible, short maxilla and normal mandible, short maxilla and longer mandible, the longer mandible is a main factor.

CONCLUSION

With the advantage of stability, SN can be used to evaluate maxilla and mandible, and decide the skeletal mechanics of crossbite individually and accurately.

[QTL mapping of the root traits in rice seedling]

Drought resistance is one of the most important traits in rice abiotic study. The report here analyzed several major root traits affecting drought resistance expression with the double haploid population (DH) from ZYQ8 (indica)/JX17 (japonica) containing 127 lines. After 10 days solution culturing, three rice root traits, Maximum Root Length (MRL), Dry Root Weight (DRW) and Root/Shoot Ratio of Dry Weight (RSR), were revealed existing significant difference among the DH lines. Using the constructed molecular linkage map from this segregating population, the QTL mapping was conducted among these three root parameters. MRL, DRW, and RSR were found being controlled by 2/1/2 QTLs respectively in JX17, 2/0/1 QTLs respectively in ZYQ8. Phenotype variance could be explained by 16.4% and 17.0% for MRL, 16.4% for DRW, 10.4% and 19.9% for RSR in JX17, 19.6% and 13.0% for MRL, 13.2% for RSR in ZYQ8. All these QTLs identified were distributed on rice chromosome 2, 3, 4, 5, 6, 9 and 10. Comparing with the other mapping results, one QTL for each trait (L169-CT106A for MRL, G45-G1314A for DRW, G62-G144 for RSR) was identical with the results reported previously.

Morphologic analysis of BMP-9 gene therapy-induced osteogenesis

The present study was performed to determine the histological, ultrastructural, and radiographic changes that occur over time at intramuscular BMP-9 gene therapy treatment sites. Several members of the bone morphogenetic protein (BMP) family have the potential to induce osteochondrogenesis when the protein is delivered to rodents, canines, rabbits, and nonhuman primates. Previous studies have also demonstrated that BMP gene therapy utilizing adenoviral vectors can also stimulate orthotopic and heterotopic bone formation in rodents and rabbits. Athymic nude and Sprague-Dawley rats were injected with Ad-BMP-9 or Ad-beta-Gal (3.75 x 10(9) particles) in their thigh musculature and light microscopic, electron microscopic, and computerized tomography analysis was performed 3, 6, 9, 12, 15, 18, 21, and 100 days later. To assess early mesenchymal cell proliferation, a bromodeoxyuridine (BrdU) immunohistochemical analysis was also performed 48, 60, and 72 hr postinjection in athymic nude rats. All animals demonstrated extensive endochondral bone formation at the Ad-BMP-9 treatment sites within 3 weeks. The Sprague-Dawley rats also exhibited a massive, acute inflammatory infiltrate during the first week. Proliferating mesenchymal stem cells were clearly evident as early as 2 days after treatment, which differentiated into small or hypertrophied chondrocytes during the next week. During the third week, the cartilaginous matrix mineralized and formed woven bone, which converted to lamellar bone by 3 months. No evidence of bone formation was demonstrated at the Ad-beta-Gal injection sites in the athymic nude or Sprague-Dawley rats. In addition, no cellular proliferation was seen at the Ad-beta-Gal treatment sites in the athymic nude animals as assessed by light microscopy and BrdU immunohistochemistry. The extensive bone formation induced by Ad-BMP-9 suggests that BMP gene therapy may have potential utility in the treatment of degenerative, rheumatic, or traumatic bone pathology.

[Translation initiation function of the regulation element in the operon of cholera toxin A]

To demonstrate that there existed translation coupling between cholera toxin A subunit gene and B subunit gene, and give the answer why the expression level of B gene is five times more than that of A gene, alpha report system for the investigation of translation coupling was constructed by using lacZ gene as reporter. Frame-shift mutation was introduced near the C terminal of ctxA gene, and the ribosome would read through its normal stop codon. The report plasmid was constructed and it was found that the expression level of lacZ gene decreased five times after the frame-shift mutation. The translation of cholera toxin B subunit gene was translational coupled with A subunit gene, and was responsible for the differential expression level of the two genes.

[A new model of translational control of gene expression in polycistron++ of AB5 entrerotoxin]

The expression level of the B subunit gene of cholera toxin (ctx) and E. coli heat labile toxin (ltx) is five to seven times more than that of A subunit gene. In these studies, a 80 basepair translation regulation element was found located in the structure gene of A gene of both toxin operon which consists of three translation initiation region. Site-directed mutation of the initiation codon of TIR3 resulted in the 9 time decrease of the expression of the downstream cistron which was translational coupled with A gene. The results indicated that translation from the internal of A gene and translation coupling are responsible for the differential expression level of the A and B gene of AB5 enterotoxin.

[Therapeutic effect of Astragalus and Angelica on renal injury induced by ischemia/reperfusion in rats]

OBJECTIVE

To observe the effect of Astragalus and Angelica on acute renal injury.

METHODS

Using the ischemia/reperfusion model established by blocking blood flow through clamping of bilateral renal artery for 45 min, the changes of glomerular filtration rate (GFR), renal plasma flow (RPF), fractional excretion of sodium (FENa), urinary volume (UV) and mean arterial pressure (MAP) as well as the morphological change of kidney before and after ischemia/reperfusion were observed.

RESULTS

Astragalus and Angelica could promote recovery of RPF and GFR after ischemia/reperfusion, prevent the oliguria or shorten the oliguria period, reduce the increment of FENa and improve the histomorphological injury of kidney.

CONCLUSION

Astragalus and Angelica have certain effect in protecting kidney from acute renal injury.

[Study on gene-dosage effect of high level expression of the yeast glucoamylase genes]

Diploid strains homozygous for both MAT allele and STA genes (a/a, STA1/STA1 or STA2/STA2 or STA3/STA3) and diploid strains homozygous for MAT allele but intercombinative for STA genes (a/a, STA1/STA2 or STA2/STA3 or STA1/STA3) were constructed by means of the protoplast fusion or the colchicine treatment. According to glucoamylase activity in YPS medium, we studied the gene-dosage effect and their interrelation of these three polymeric genes coding for glucoamylase. The results of the glucoamylase activity determination showed that the gene-dosage effect of glucoamylase is obvious in diploid and triploid strains homozygous for both MAT allele and STA gene, such as the glucoamylase activity of a diploid strain SFY56-6 and a triploid strain SFY56-104 homozygous for both MAT allele and STA genes were respectively 2.35 and 3.18-fold as compared with that of the their parental strain IATA-Y56 that is a haploid Saccharomyces diastaticus. Moreover, the glucoamylase activity of diploid strains homozygous for MAT allele but intercombinative for STA genes also showed the combinative gene-dosage effect to a certain extent.

[Assessment of malaria DNA vaccines in mice and monkeys]

Cholera toxin B subunit is a good carrier protein and an effective adjuvant which can boost both cellular and humoral immunity. DNA fragments encoding B cell, Th cell and CTL epitopes of P. falciparum CS, MSA-1, MSA-2 and RESA antigens were cloned down-2 stream of cholera toxin B subunit gene in the same reading frame. High titer of anti-malaria epitopes antibodies and strong cellular immunogenicity were elicited after Balb/c mice were immunized three times with 100 micrograms recombinant plasmid DNA dissolved in 100 microliters PBS. A total of 120 vaccinees were challenged with mouse Plasmodium yoelli to investigate if cross protection existed. The protective efficacy was about 60%-80%. Four rhesus monkeys were challenged with 10(8) of P. cynomalgi, better results were obtained in the groups immunized with mixed plasmids including NANP, AWTE.

[Induction of protective immune response in mice and rhesus monkeys by immunization with fusion protein of cholera toxin B subunit and multiples of Plasmodium falciparum]

Recombinant fusion protein of cholera toxin B subunit (CTB) and poly-valent protective epitopes of plasmodium falciparum was given to i.m. to C57BL/6j mice and rhesus monkeys three times. In rhesus monkeys, high level of antibodies for CTB (1:6400) and malaria epitopes (1:3200) amtobpdoes were elicited as well as the specific CTL activity for P. plasmodium. After the mice were challenged with sporozoites of P. yeolli, about 50% of them were protected from the patent infection. A blood-stage challenge with 10(8) of P. cynomolgi parasite were given to rhesus monkeys, which showed that two animals in control group were patent infection for at least 30 days, in contrast, the two animals immunized were recovered respectively at the day of 11 and 15 after challenges. The results suggested that cholera toxin acts as an effective adjuvent in the development of malaria vaccine.

Classical oncogenes and tumor suppressor genes: a comparative genomics perspective

We have curated a reference set of cancer- related genes and reanalyzed their sequences in the light of molecular information and resources that have become available since they were first cloned. Homology studies were carried out for human oncogenes and tumor suppressors, compared with the complete proteome of the nematode, Caenorhabditis elegans, and partial proteomes of mouse and rat and the fruit fly, Drosophila melanogaster. Our results demonstrate that simple, semi-automated bioinformatics approaches to identifying putative functionally equivalent gene products in different organisms may often be misleading. An electronic supplement to this article provides an integrated view of our comparative genomics analysis as well as mapping data, physical cDNA resources and links to published literature and reviews, thus creating a "window" into the genomes of humans and other organisms for cancer biology.

[Application of microsatellite markers for the seed purity examination of a hybrid rice, Gangyou-22]

For seed commercialization of hybrid rice it is necessary to examine the purity of its seeds before field-production, because the seed purity is closely related to their heterosis performance and yield increase. In this research, 160 microsatellite markers were used for PCR amplification of rice seedling DNAs of Gangyou-22, which is a major hybrid rice in China, and its parents, Gang46A(CMS line) and CDR22(restorer line). A microsatellite marker, RM168, was screened out for its ability to produce polymorphic bands specific to each of the two parents but different from other 22 restorer lines and 9 cultivars. This provides an accurate and efficient method to examine the purity of a hybrid rice at an earlier time. Amplification of DNAs extracted from seeds and application of two microsatellite markers in one PCR system can further simplify the procedure and improve the accuracy of the seed purity examination.

TNF-alpha increases albumin permeability of isolated rat glomeruli through the generation of superoxide

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine that plays a central role in inflammation. Glomerular levels of TNF-alpha are elevated in human and experimental glomerulonephritis. Glomerular cells produce and respond to TNF-alpha. One of the mechanisms by which these cells respond to TNF-alpha is through generation of reactive oxygen species. In this study, the effect of TNF-alpha on albumin permeability (P(albumin)) of isolated rat glomeruli and the possible mechanism of this effect were examined. Isolated rat glomeruli were incubated with TNF-alpha (0.4 ng/ml), TNF-alpha with anti-TNF-alpha antibodies, and TNF-alpha with the reactive oxygen species scavengers superoxide dismutase, catalase, DMSO, or dimethylthiourea for 12 min at 37 degrees C, and P(albumin) was calculated. TNF-alpha increased P(albumin) of isolated glomeruli compared with control (0.70 +/- 0.02, n = 25 versus 0.00 +/- 0.05, n = 26), and this effect was abrogated by anti-TNF-alpha antibodies (-0.18 +/- 0.05, n = 23). Superoxide dismutase abolished the increase in P(albumin) (-0.04 +/- 0.11, n = 23), whereas catalase (0.73 +/- 0.08, n = 30), DMSO (0.64 +/- 0.03, n = 10), or dimethylthiourea (0.51 +/- 0.08, n = 10) did not alter the effect of TNF-alpha. These results indicate that TNF-alpha increased P(albumin+)++ of isolated glomeruli and that the mediator of the increased P(albumin) is superoxide. It is concluded that TNF-alpha derived from glomerular or extraglomerular sources can increase glomerular P(albumin) through generation of superoxide and may lead to proteinuria.

Inhibitory effect of Tripterygium wilfordii multiglycoside on increased glomerular albumin permeability in vitro

BACKGROUND

Tripterygium wilfordii Hook F is a medicinal plant used for the treatment of glomerulonephritis in China. We studied the effect of Tripterygium wilfordii multiglycoside (TWG) on glomerular albumin permeability (Palbumin) in vitro.

METHODS

Isolated rat glomeruli were incubated with protamine (600 micrograms/ml) for 30 min, or with human recombinant tumour necrosis factor (TNF-alpha 0.4 ng/ml), superoxide (10 units/ml), or serum from a focal segmental glomerular sclerosis (FSGS) patient for 10 min at 37 degrees C. TWG, 1 mg/ml, was added in parallel tubes to study the effect on Palbumin. Control glomeruli were incubated under identical conditions. The albumin reflection coefficient (sigma albumin) was calculated from the change in glomerular volume in response to an applied oncotic gradient. Convectional permeability (Palbumin) was calculated as (1 - sigma albumin).

RESULTS

Compared with controls, protamine increased the Palbumin of glomeruli (0.83 +/- 0.05, n = 25, vs 0.18 +/- 0.03, n = 20); pretreatment with TWG blocked this effect (0.13 +/- 0.04, n = 25). TNF-alpha also increased the Palbumin (0.79 +/- 0.04, n = 24 vs 0.04 +/- 0.07, n = 19); preincubation with TWG blocked this effect (0.03 +/- 0.09, n = 24). Palbumin of glomeruli incubated with xanthine and xanthine oxidase, resulting in the production of superoxide, also increased as compared to controls (0.85 +/- 0.04, n = 15 vs 0.08 +/- 0.05, n = 14); TWG blocked this effect as well (0.21 +/- 0.08, n = 14). FSGS serum also increased Palbumin of glomeruli significantly (0.88 +/- 0.02, n = 49 vs 0.00 +/- 0.02, n = 49); preincubation with TWG blocked this effect (0.05 +/- 0.07, n = 30). TWG by itself had no effect on Palbumin (0.19 +/- 0.10, n = 15).

CONCLUSIONS

Our results show that TWG blocks protamine, TNF-alpha, superoxide, and FSGS serum-mediated increase in glomerular albumin permeability in vitro. We conclude that reduction of proteinuria by Tripterygium wilfordii multiglycoside in various kinds of glomerular diseases in vivo might be due to protection of the glomerular filtration barrier.

[The preliminary results of prevention and treatment in the population of patients with COPD and cor pulmonale]

This paper tends to evaluate the effects of comprehensive prevention and treatment in COPD and cor pulmonale in the communities. A Randomized cohort with stratified design was undertaken in the rural areas with hundred thousand population in Beijing municipality, Lianning and Hubei Provinces, from spring 1992 to spring 1995.

RESULTS

(1) the rates to all stratified populations under management were 85.6% among those with high risk, 87.8% among COPD and 83.6% among cor pulmonale, respectively. (2) The levels of KAB were raised more significantly in most intervention group than in control group which up +9.6% to +33.6% and -5.8% to +32.6%, respectively. (3) Comparisons between the two groups revealed: 1. Number of cigarette smokers who smoked more than before increased (20.1% vs 17.8%) but with no statistical significance. 2. The rate of smoking cessation went higher (15.5% vs. 11.3%, P < 0.01). 3. New high risk subjects were reduced (2.8% vs 3.9%, P < 0.01). 4. Number of new cor pulmonale patients decreased (19.9% vs 22.6%, P > 0.05) and mortality rate lowered (4.34% vs 4.78%, P > 0.05).

CONCLUSION

preliminary results indicates that the active intervention is effective in reducing COPD and cor pulmonale among population at high risk in communities. However, it is necessary to point out that COPD and cor pulmonale are both having chronic nature which calls for patient and continuous efforts.

[Effect of Astragalus Angelica mixture on serum lipids and glomerulosclerosis in rats with nephrotic syndrome]

OBJECTIVE

To confirm the renal protective action of Astragalus Angelica mixture (AAM).

METHODS

Effect of AAM was observed in puromycin amino-nucleoside induced nephrotic syndrome model of rat, and pravachol, an effective lipid lowering medicine, was used as positive control.

RESULTS

AAM could not only reduce the serum levels of total cholesterol and triglyceride as pravachol did, but also could lower levels of low density lipoprotein and apolipoprotein B100 (P < 0.05). Light microscopic and immuno-histochemical examination revealed that in the same time of lowering serum lipids, this mixture could also cause reduction of glomerular sclerosing index (P < 0.01) and less accumulation of extracellular matrix (P < 0.01).

CONCLUSIONS

AAM has the effects of regulating lipid metabolism, attenuating renal damage and maintaining renal function in rats with nephrotic syndrome.

The activation of human platelets mediated by two monoclonal antibodies raised against CD9

The platelet activation induced by two anti-human platelet P24/CD9 McAbs was investigated. The results showed that: the pathway of platelet aggregation induced by the two McAbs (HI117 and SJ9A4) is not the same; HI117 and SJ9A4 induced the phosphorylation of platelet proteins (40KD and 20KD) when platelets were activated; but HI117 didn't cause a rise in intracellular Ca2+ concentration in activated platelets compared with SJ9A4; the epitope recognized by HI117 and SJ9A4 is different and this is probably the real reason why the two CD9 McAbs play different roles in platelet activation. Additionally McAbs HI117 and SJ9A4 could not promote associates of other proteins (e.g.: GPIIb/IIIa) with P24/CD9 on activated human platelets. All these results indicate that the mechanism of platelet activation induced by HI117 or SJ9A4 is different form each other. It suggests that CD9 antigen play an important and complex role in platelet activation.

Direct effects of platelet-activating factor on glomerular capillary permeability

Platelet-activating factor (PAF) is an important mediator of injury in acute renal failure and glomerulonephritis. Intrarenal infusion of PAF reduces glomerular filtration rate and renal plasma flow and increases glomerular permselectivity via its renal hemodynamic and/or immunologic effects. Direct effects of PAF on glomerular capillary permeability are not known. We studied the direct effects of PAF on mesangial contraction (a measure of filtration area), glomerular capillary hydraulic conductivity (L[p]) and capillary albumin permeability (P[albumin]). Glomeruli were isolated from Sprague-Dawley rats and incubated with or without various concentrations of PAF (10[-9], 10[-7] and 10[-5] M) for up to 5 h at 37 degrees C. Mesangial contraction (percent change in glomerular volume) was assessed from the gradual decrease in volume of glomeruli during 20 min of incubation with PAF. L(p) was calculated from the rate of change in glomerular volume during the 0.1 s of capillary expansion in response to a transcapillary oncotic gradient. P(albumin) was calculated from a change in relative volume of glomeruli in response to an oncotic gradient. Mesangial contraction was maximal after 20 min of incubation and was concentration dependent (5.2+/-0.9, 7.9+/-1.0 and 10.0+/-1.0%, respectively, with PAF 10(-9), 10(-7) and 10(-5) M). Incubation of glomeruli with PAF 10(-7) M for 60 min at 37 degrees C caused a significant decrease in L(p) (2.25+/-0.30 vs. control 3.12+/-0.28 microl x min(-1) x mm Hg(-1) x cm(-1), n = 5). P(albumin) of glomeruli incubated with PAF was unchanged up to 2 h but increased significantly with the highest concentration of PAF (10(-5) M) after 3 h of incubation (0.60+/-0.18, n=15, vs. control 0.00+/-0.08, n = 20), whereas lower concentrations of PAF (10[-7] or 10[-9] M) required at least 5 h of incubation with glomeruli to cause a significant increase in P(albumin) (0.45+/-0.09 and 0.48+/-0.07, respectively, n=15, vs. control 0.00+/-0.08, n=15). We conclude that PAF has multiple direct effects on glomerular functions, which are time dependent and may contribute to the altered capillary permeability in vivo.