Luis C. Sanz

Spermadhesin PSP-I/PSP-II heterodimer induces migration of polymorphonuclear neutrophils into the uterine cavity of the sow

Seminal plasma (SP) is a complex fluid which exerts biological actions in the female reproductive tract. In pigs, SP elicits endometrial inflammation and consequent immune changes after mating. This study tested whether heparin-binding spermadhesins (HBPs) and the heterodimer of porcine sperm adhesions I and II (PSP-I/PSP-II) in SP recruit different lymphocyte subsets (CD2(+), CD4(+) and CD8(+) T cells) or polymorphonuclear leukocytes (PMNs) to the superficial endometrium or luminal epithelium and lumen, respectively, of oestrous sows. In Experiment 1, endometrial biopsies were taken between 2 and 120 min after infusion of uterine horns with HBPs, PSP-I/PSP-II or saline and evaluated by immunohistochemistry or histology. In Experiment 2, the uterus of oestrous sows was infused with PSP-I/PSP-II or saline to assess PMN numbers in the uterine lumen 3h later. PSP-I/PSP-II elicited CD2+ T cell recruitment from 10 min, and CD8(+) T cells from 60 min after infusion, while HBPs increased CD4(+) T cell recruitment by 120 min. PSP-I/PSP-II but not HBPs induced PMN migration to the surface epithelium by 10 min. PMN numbers were elevated 5-fold by 30 min and 7-fold from 60 min, with PMNs detectable in the lumen from 30 min after infusion. Six-fold more PMNs were collected from the uterine lumen of PSP-I/PSP-II-infused sows compared to controls at 3h after infusion. These data show that PSP-I/PSP-II heterodimer in seminal plasma has a predominant role in triggering the recruitment of uterine PMNs and T cells after mating, initiating a cascade of transient and long-lasting immunological events.

Effect of methyl jasmonate on ethylene biosynthesis and stomatal closure in olive leaves

Abstract The influence of methyl jasmonate (MeJA) on ethylene production and 1-aminocyclopropane-1-carboxylic acid (ACC) and malonyl-ACC (MACC) contents in olive leaf discs and detached leaves was investigated. In leaf discs, both ACC content and ethylene-forming enzyme (EFE) activity were clearly stimulated by 45 μM MEJA. In detached leaves MeJA treatment increased ACC content with no clear increase in ethylene production. When detached leaves were incubated with MeJA (45 μM) and ACC (1 mM), the total endogenous ACC content was significantly lower than that of leaves incubated only with ACC (1 mM). These data could be explained on the basis that MeJA caused stomatal closure, and hence reduced ACC uptake.

Purification and catalytic properties of chickpea lipoxygenases

Abstract Two lipoxygenase isoenzymes, CL-1 and CL-2, were purified to apparent homogeneity from chickpea cv Pedroxillano by ammonium sulphate fractionation, gel filtration, ion exchange and hydrophobic chromatography. CL-1 and CL-2 had pH optima of 6.0 and 5.5, with apparent KM values for linoleic acid of 192 and 51μM respectively. Unlike CL-2, which produced only hydroperoxides, CL-1 simultaneously produced hydroperoxides and carbonyl compounds and exhibited high co-oxidative activity with carotene and retinol substrates. Both isoenzymes preferred linoleic acid as substrate. CL-1 was thermally more stable than CL-2, and exhibited the unusual property that its specific activity decreased with enzyme concentration.

Characterization of lupin seed lipase

Abstract Crude lipase has been extracted from ungerminated lupin seed. The lipase has an optimal activity at pH 5·0, an optimum temperature of 25°C and an activation energy of 1·32kJ mol−1, showing an induction period of 10 min. A crude extract lost more than 70% of lipase activity after 24 h. Lipase activity is stimulated by the concurrent presence of potassium (10 m m ) with calcium (1 m m ) or magnesium (1m m ) ions. The enzyme exhibits a certain specificity in releasing fatty acids from the primary rather than from the secondary position of triglycerides of lupin oil. At the primary position it is more active on saturated than on unsaturated fatty acids.

Physico-chemical properties of chickpea lipoxygenases

Abstract Purified lipoxygenase isoenzymes from chickpea ( Cicer arietinum ) cv Pedroxillano are single polypeptide chains with M r s of 96 000–97 000, determined by hydrodynamic and electrophoretic methods. Both isoenzymes difrered in pI , 4.92 for CL-1 and 4.74 for CL-2. Each isoenzyme contained one atom of iron in a divalent oxidation state. CL-1 contained 760 amino acid residues and CL-2 753 residues, with a high proportion of hydrophobic amino acids, particularly proline and leucine. Eight and seven cysteines were also present, two and three of which were as free sulphydryl residues, in CL- 1 and CL-2, respectively. Thiols, sulphur bridges and carboxyl and amine groups seemed to be essential in the maintenance of a catalytically active tertiary structure in both isoenzymes. CL-2 formed mainly 13-hydroperoxy-(9 Z , 11 E )-octadecadienoic acid from linoleic acid, while CL- 1 yielded almost equal proportions of the 9-and 13-hydroperoxides, and the 9- and 13-ketodienes.