Phoneutria nigriventer (armed spider) venom induces increased vascular permeability in rat and rabbit skin in vivo

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe effect of intradermally injected Phoneutria nigriventer venom (PNV) on vascular permeability of both rat and rabbit skin has been investigated. Oedema formation was measured as the local extravascular accumulation at skin sites of intravenously injected 125I-human serum albumin. In both rat and rabbit PNV induced dose-dependent oedema which was greatly potentiated by the vasodilators calcitonin-gene-related peptide and prostaglandin E1. In rats, PNV-induced oedema was markedly reduced either by previous treatment of the animals with the histamine H1 antagonist mepyramine and the serotonin antagonist methysergide or when venom was dialysed, indicating a major role for histamine and serotonin. In rabbits, dialysis of the venom to remove histamine and serotonin did not reduce PNV-induced oedema, indicating presence of oedematogenic component(s) which are different from the amines histamine or serotonin.The effect of intradermally injected Phoneutria nigriventer venom (PNV) on vascular permeability of both rat and rabbit skin has been investigated. Oedema formation was measured as the local extravascular accumulation at skin sites of intravenously injected 125I-human serum albumin. In both rat and rabbit PNV induced dose-dependent oedema which was greatly potentiated by the vasodilators calcitonin-gene-related peptide and prostaglandin E1. In rats, PNV-induced oedema was markedly reduced either by previous treatment of the animals with the histamine H1 antagonist mepyramine and the serotonin antagonist methysergide or when venom was dialysed, indicating a major role for histamine and serotonin. In rabbits, dialysis of the venom to remove histamine and serotonin did not reduce PNV-induced oedema, indicating presence of oedematogenic component(s) which are different from the amines histamine or serotonin30910111016FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO90/12341; 90/4145-

Phoneutria Nigriventer (armed Spider) Venom Induces Increased Vascular Permeability In Rat And Rabbit Skin In Vivo

The effect of intradermally injected Phoneutria nigriventer venom (PNV) on vascular permeability of both rat and rabbit skin has been investigated. Oedema formation was measured as the local extravascular accumulation at skin sites of intravenously injected 125I-human serum albumin. In both rat and rabbit PNV induced dose-dependent oedema which was greatly potentiated by the vasodilators calcitonin-gene-related peptide and prostaglandin E1. In rats, PNV-induced oedema was markedly reduced either by previous treatment of the animals with the histamine H1 antagonist mepyramine and the serotonin antagonist methysergide or when venom was dialysed, indicating a major role for histamine and serotonin. In rabbits, dialysis of the venom to remove histamine and serotonin did not reduce PNV-induced oedema, indicating presence of oedematogenic component(s) which are different from the amines histamine or serotonin. © 1992.30910111016Antunes, Marangoni, Borges, Fontana, de Nucci, Pharmacological profile of Phoneutria nigriventer venom on rabbit vascular smooth muscle (1990) British Journal of Pharmacology, 101, p. 508PBrain, Williams, Inflammatory oedema induced by synergism between calcitonin gene-related peptide (CGRP) and mediators of increased vascular permeability (1985) Br. J. Pharmac., 86, pp. 855-860Diniz, Cordeiro, Junior, Kelly, Fischer, Reiman, Oliveira, Richardson, The purification and amino acid sequence of the lethal neurotoxin Tx1 from the venom of the Brazilian ‘armed’ spider Phoneutria nigriventer (1990) FEBS Lett., 263, pp. 251-253Entwistle, Johnstone, Medzihradszky, May, Isolation of a pure toxic polypeptide from the venom of the spider Phoneutria nigriventer and its neurophysiological activity on an insect femur preparation (1982) Toxicon, 20, pp. 1059-1067Fontana, Vital-Brazil, Mode of action of Phoneutria nigriventer spider venom at the isolated phrenic nerve-diaphragm of the rat (1985) Braz. J. Med. Biol. Res., 18, pp. 557-565Kaiser, The enzymatic activity of spider venom (1953) Mem. Inst. Butantan, 25, pp. 35-39Lucas, Spiders in Brazil (1988) Toxicon, 26, pp. 759-772Rezende, Jr, Cordeiro, Oliveira, Diniz, Isolation of neurotoxic peptides from the venom of the armed spider Phoneutria nigriventer (1991) Toxicon, 29, pp. 1225-1233Schenberg, Pereira-Lima, Phoneutria nigriventer venom (1971) Pharmacology and biochemistry of its components, 3, pp. 279-297. , W. Bucherl, E.E. Buckley, Venomous Animals and their Venoms, Academic Press, New YorkSpector, Willoughby, Endogenous mediators of increased vascular permeability in inflammation (1968) The Pharmacology of Inflammation, pp. 22-54. , English Universities Press LtdVital-Brazil, Leite, Fontana, Modo de ação da peçonha da aranha armadeira, Phoneutria nigriventer (Keyserling, 1891), nas aurículas isoladas de cobaia (1988) Ciênc. Cult., S Paulo, 40, pp. 181-185Williams, Prostaglandin E2, prostaglandin I2 and the vascular changes of inflammation (1979) Br. J. Pharmac., 65, pp. 517-52

Activation By Phoneutria Nigriventer (armed Spider) Venom Of Tissue Kallikrein-kininogen-kinin System In Rabbit Skin In Vivo

1. The purpose of the present study was to investigate the mechanisms by which venom from Phoneutria nigriventer spider induces increases in vascular permeability in rabbit skin. 2. Local oedema formation, in response to intradermally -injected agents, was measured in male New Zealand white rabbits as the local accumulation of i.v. injected 125I-labelled human serum albumin into skin sites. 3. Phoneutria nigriventer venom (10-30 μg/site) increased vascular permeability, which was inhibited by trasylol (10 μg/site) and the bradykinin B2 receptor antagonists D-Arg, [Hyp3,Thi5,8,D-Phe7]-BK (3 nmol/site) and Hoe 140 (0.3 nmol/site). In addition, the oedema induced by the venom was potentiated by the kinase II inhibitor, captopril (1 nmol/site). The lipoxygenased inhibitor, BWA4C (10 nmol/site) and the PAF antagonist, WEB 2086 (100 nmol/site) had no effect on the venom-induced increase in vascular permeability. 4. Incubation of rabbit plasma with Phoneutria nigriventer venom in vitro did not cause bradykinin formation. Further, the plasma kallikrein inhibitor, soybean trypsin inhibitor (10 μg/site), had no effect on the venom-induced increase in vascular permeability in rabbit skin. 5. These results indicate that the oedema produced by Phoneutria nigriventer venom is dependent on the activation of the tissue kallikrein-kinin system.109253954

Activation Of Tissue Kallikrein-kininogen-kinin System In Rabbit Skin By A Fraction Isolated From Phoneutria Nigriventer (armed Spider) Venom

Phoneutria nigriventer venom was fractionated by gel filtration followed by ion-exchange chromatography from which 16 fractions (I-XVI) were obtained and assayed in rabbit skin in order to identify those responsible for the increased vascular permeability observed with the whole venom. The fractions, and control mediators (tissue kallikrein, bradykinin and histamine) were intradermally injected in male New Zealand white rabbits. Local oedema formation was measured as the local accumulation of i.v. injected 125I-human serum albumin into skin sites. Fraction XIII was the only fraction assayed which significantly induced oedema formation. Fraction XIII-induced oedema was greatly reduced by either the protease inhibitor aprotinin or the bradykinin B2 receptor antagonist d-Arg,[Hyp3,Thi5,8,d-Phe7]-Bk, whereas the plasma kallikrein inhibitor soybean trypsin inhibitor failed to significantly affect this oedematogenic response. The kininase II inhibitor captopril markedly potentiated fraction XIII-induced oedema. Our results indicate that the increased vascular permeability induced by fraction XIII is due to local generation of kinins in response to tissue (but not plasma) kallikrein-kinin system activation. © 1993.311113851391Antunes, Marangoni, Brain, de Nucci, Phoneutria nigriventer (armed spider) venom induces increased vascular permeability in rat and rabbit skin in vivo (1992) Toxicon, 30, pp. 1011-1016Antunes, Marangoni, Borges, Hyslop, Fontana, de Nucci, Effect of Phoneutria nigriventer on rabbit vascular smooth muscle (1993) Braz. J. Med. Biol. Res., 26, pp. 81-91Brain, Williams, Inflammatory oedema induced by synergism between calcitonin gene-related peptide (CGRP) and mediators of increased vascular permeability (1985) Br. J. Pharmac., 86, pp. 855-860Brazil, Vellard, Contribuição ao estudo de venenos de aranhas (1925) Mem. Inst. Butantan, 2, pp. 1-70Brazil, Vellard, Contribuição ao estudo do veneno das aranhas II (1926) Mem. Inst. Butantan, 3, pp. 3-77Brazil, Vellard, Contribuição ao estudo do veneno das aranhas III (1926) Mem. Inst. Butantan, 3, pp. 243-294Chao, Tanaka, Margolius, Inhibitory effects of sodium and other monovalent cations on purified versus membrane-bound kallikrein (1983) J. biol. Chem., 258, pp. 6461-6465Cushman, Cheung, Sabo, Ondetti, Design of potent competitive inhibitors of angiotensin-converting enzyme. Carboxyalkanoyl and mercaptoalkanoyl amino acids (1977) Biochemistry, 16, pp. 5484-5491Diniz, Separação de proteínas e caracterização de substâncias ativas em venenos de aranhas do Brasil (1963) An. Acad. Bras. Sci., 35, pp. 283-291Entwistle, Johnstone, Medzihradszky, May, Isolation of a pure toxic polypeptide from the venom of the spider Phoneutria nigriventer and its neurophysiological activity on an insect femur preparation (1982) Toxicon, 20, pp. 1059-1067Fontana, Vital Brazil, Mode of action of Phoneutria nigriventer spider venom at the isolated phrenic nerve-diaphragm of the rat (1985) Braz. J. Med. Biol. Res., 18, pp. 557-565Fuller, Clements, Whitfield, Funder, Kallikrein gene expression in the rat anterior pituitary (1985) Mol. Cell. Endocrin., 39, pp. 99-105Jong, Norment, Heitz, Separation and characterization of venom components in Loxosceles reclusa—II. Protease enzyme activity (1979) Toxicon, 17, pp. 529-537Lazure, Leduc, Seidah, Chretien, Dube, Chapdelaine, Frenette, Tremblay, The major androgen-dependent protease in dog prostate belongs to the kallikrein family: confirmation by partial amino acid sequencing (1984) FEBS Lett., 175, pp. 1-7Lieberthal, Oza, Bernard, Levinsky, The effect of cations on the activity of human urinary kallikrein (1982) J. biol. Chem., 257, pp. 10,827-10,830Lucas, Spiders in Brazil (1988) Toxicon, 26, pp. 759-772Marangoni, Antunes, Brain, de Nucci, Phoneutria nigriventer (armed spider) venom activates tissue kallikrein-kininogen-kinin system in rabbit skin in vivo (1993) Br. J. Pharmac., 109, pp. 539-543Marangoni, Borges, Marangoni, Antunes, Vieira, Novello, Domont, de Nucci, Biochemical characterization of a vascular smooth muscle contracting polypeptide purified from Phoneutria nigriventer (armed spider) venom (1993) Toxicon, 31, pp. 377-384Margolius, Tissue kallikreins and kinins: regulation and roles in hypertensive and diabetic diseases (1989) A. Rev. Pharmac. Toxicol., 29, pp. 343-364Perret, Proteolytic activity of Tarantula venoms due to contamination with saliva (1977) Toxicon, 15, pp. 505-510Powers, Nasjletti, A novel kinin-generating protease (kininogenase) in the porcine anterior pituitary (1982) J. biol. Chem., 257, pp. 5594-5600Powers, Nasjletti, A kininogenase resembling glandular kallikrein in the rat pituitary pars intermedia (1983) Endocrinology, 112, pp. 1194-1200Proud, Kaplan, Kinin formation: mechanisms and role in inflammatory disorders (1988) A. Rev. Immunol., 6, pp. 49-83Proud, Bailey, Nustad, Gautvik, The immunological similarity of rat glandular kallikreins (1977) Biochem. J., 167, pp. 835-838Rezende, Jr, Cordeiro, Oliveira, Diniz, Isolation of neurotoxic peptides from the venom of the ‘armed spider’ Phoneutria nigriventer (1991) Toxicon, 29, pp. 1225-1233Schachter, Peret, Billing, Wheeler, Longridge, Immunolocalization of the protease kallikrein in the colon (1983) J. Histochem. Cytochem., 31, pp. 1255-1260Schenberg, Pereira-Lima, Pharmacology of the polypeptides from the venom of the spider Phoneutria fera (1966) Mem. Inst. Butantan, 33, pp. 627-638Schenberg, Pereira-Lima, Phoneutria nigriventer venom (1971) Pharmacology and biochemistry of its components, 3, pp. 279-297. , W. Bucherl, E.E. Buckley, Venomous Animals and Their Venoms, Academic Press, New YorkSpector, Willoughby, Endogenous mediators of increased vascular permeability in inflammation (1968) The Pharmacology of Inflammation, pp. 22-54. , English Universities PressVavrek, Stewart, Competitive antagonists of bradykinin (1985) Peptides, 6, pp. 161-164Vital Brazil, Leite, Fontana, Modo de ação da peçonha da aranha armadeira, Phoneutria nigriventer (Keyserling, 1891), nas aurículas isoladas de cobaia (1988) Cien̂c. Cul. S. Paulo, 40, pp. 181-185Vogel, Kallikrein inhibitors (1979) Bradykinin, Kallidin and Kallikrein. Handbook of Experimental Pharmacology, 25, pp. 163-225. , Springer, BerlinWilliams, Prostaglandin E2, prostaglandin I2 and the vascular changes of inflammation (1979) Br. J. Pharmac., 65, pp. 517-524Williams, Morley, Prostaglandins as potentiators of increased vascular permeability in inflammation (1973) Nature, 246, pp. 215-21

Effects of phoneutria-nigriventer venom on rabbit vascular smooth-muscle

The effects of Phoneutria nigriventer venom (PNV) on rabbit vascular smooth muscle have been investigated. De-endothelialized vascular strips were superfused in a cascade system with oxygenated (95% O2 + 5% CO2) Krebs solution at 37-degrees-C. 2. Phoneutria nigriventer venom (0.3-30 mug) produced dose-dependent and short-lived contractions of both venous (cava, mesenteric and jugular veins) and arterial (pulmonary and mesentetic arteries) tissues. 3. Methysergide (5.0 muM) did not significantly affect PNV-induced contractions in venous tissues (cava and mesenteric veins) or pulmonary artery, indicating that serotonin is not involved in the contraction. This was confirmed when PNV was dialyzed (24-48 h) since the contracting activity was still observed on the above tissues. In addition, the spasmogenic activity induced by dialyzed PNV was greatly reduced by incubating the venom with trypsin. 4. Neither tetrodotoxin (3.0 muM) nor phenoxybenzamine (0.05 muM) significantly affected PNV-induced contractions, suggesting that voltage-dependent sodium channel activation or endogenous catecholamine release from autonomic nerve endings on the vascular walls do not play a role in the response to PNV. 5. Our results demonstrate that PNV contains non-dialyzable components, probably peptides, that are responsible for the contractile activity on rabbit veins and pulmonary artery stripsAssociação Brasileira de Divulgação Científica2618191BrasilBrazilian journal of medical and biological researchBrazilian j. med. biol. res.São Paulo, S

Effects of phoneutria nigriventer venom on rabbit vascular smooth muscle

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO1. The effects of Phneutria nigriventer venom (PNV) on rabbit vascular smooth muscle have been investigated. De-endothelialized vascular strips were superfused in a cascade system with oxygenated (95% O2 + 5% CO2) Krebs solution at 37 degrees C. 2. Phoneutria nigriventer venom (0.3-30 micrograms) produced dose-dependent and short-lived contractions of both venous (cava, mesenteric and jugular veins) and arterial (pulmonary and mesenteric arteries) tissues. 3. Methysergide (5.0 microM) did not significantly affect PNV-induced contractions in venous tissues (cava and mesenteric veins) or pulmonary artery, indicating that serotonin is not involved in the contraction. This was confirmed when PNV was dialyzed (24-48 h) since the contracting activity was still observed on the above tissues. In addition, the spasmogenic activity induced by dialyzed PNV was greatly reduced by incubating the venom with trypsin. 4. Neither tetrodotoxin (3.0 microM) nor phenoxybenzamine (0.05 microM) significantly affected PNV-induced contractions, suggesting that voltage-dependent sodium channel activation or endogenous catecholamine release from autonomic nerve endings on the vascular walls do not play a role in the response to PNV. 5. Our results demonstrate that PNV contains non-dialyzable components, probably peptides, that are responsible for the contractile activity on rabbit veins and pulmonary artery strips.The effects of Phneutria nigriventer venom (PNV) on rabbit vascular smooth muscle have been investigated. De-endothelialized vascular strips were superfused in a cascade system with oxygenated (95% O2 + 5% CO2) Krebs solution at 37 degrees C. 2. Phoneutria nigriventer venom (0.3-30 micrograms) produced dose-dependent and short-lived contractions of both venous (cava, mesenteric and jugular veins) and arterial (pulmonary and mesenteric arteries) tissues. 3. Methysergide (5.0 microM) did not significantly affect PNV-induced contractions in venous tissues (cava and mesenteric veins) or pulmonary artery, indicating that serotonin is not involved in the contraction. This was confirmed when PNV was dialyzed (24-48 h) since the contracting activity was still observed on the above tissues. In addition, the spasmogenic activity induced by dialyzed PNV was greatly reduced by incubating the venom with trypsin. 4. Neither tetrodotoxin (3.0 microM) nor phenoxybenzamine (0.05 microM) significantly affected PNV-induced contractions, suggesting that voltage-dependent sodium channel activation or endogenous catecholamine release from autonomic nerve endings on the vascular walls do not play a role in the response to PNV. 5. Our results demonstrate that PNV contains non-dialyzable components, probably peptides, that are responsible for the contractile activity on rabbit veins and pulmonary artery strips2618191FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOsem informaçãosem informaçã

Biochemical-characterization of a vascular smooth-muscle contracting polypeptide purified from phoneutria-nigriventer (armed spider) venom

Crude Phoneutria nigriventer venom was fractionated by Sephadex, ion-exchange and reverse-phase high performance liquid chromatography. One protein (PNV1) with spasmogenic activity in rabbit vascular smooth muscle was isolated and biochemically characterized. PNV1 has 125 amino acid residues and a calculated mol. wt of 13,899. Special features of the amino acid composition of PNV1 are the presence of two disulfide bridges and the high percentage (27%) of Asx and Glx. The N-terminal amino acid sequence indicates that PNV1 is different from other polypeptides isolated from Phoneutria nigriventer venom31437738

Biochemical Characterization Of A Vascular Smooth Muscle Contracting Polypeptide Purified From Phoneutria Nigriventer (armed Spider) Venom

Crude Phoneutria nigriventer venom was fractionated by Sephadex, ion-exchange and reverse-phase high performance liquid chromatography. One protein (PNV1) with spasmogenic activity in rabbit vascular smooth muscle was isolated and biochemically characterized. PNV1 has 125 amino acid residues and a calculated mol. wt of 13,899. Special features of the amino acid composition of PNV1 are the presence of two disulfide bridges and the high percentage (27%) of Asx and Glx. The N-terminal amino acid sequence indicates that PNV1 is different from other polypeptides isolated from Phoneutria nigriventer venom. © 1993.314377384Antunes, Marangoni, Borges, Fontana, de Nucci, Pharmacological profile of Phoneutria nigriventer venom on rabbit vascular smooth muscle (1990) British Journal of Pharmacology, 101, p. 508PAntunes, Marangoni, Brain, de Nucci, Phoneutria nigriventer (armed spider) venom induces increased vascular permeability in rat and rabbit skin in vivo (1992) Toxicon, 30, pp. 1011-1016Diniz, Separação de proteínas e caracterização de substâncias ativas em venenos de aranhas do Brasil (1963) An. Acad. Bras. Ciênc., 35, pp. 283-291Diniz, Cordeiro, Rezende, Jr., Kelly, Fischer, Reimann, Oliveira, Richardson, The purification and amino acid sequence of the lethal neurotoxin Txl from the Brazilian armed spider, Phoneutria nigriventer (1990) FEBS Lett., 263, pp. 251-253Entwistle, Johnstone, Medzihradszky, May, Isolation of a pure toxic polypeptide from the venom of the spider Phoneutria nigriventer and its neurophysiological activity on an insect femur preparation (1982) Toxicon, 20, pp. 1059-1067Fontana, Vital-Brazil, Mode of action of Phoneutria nigriventer spider venom at the isolated phrenic nerve-diaphragm of the rat (1985) Braz. J. Med. Biol. Res., 18, pp. 557-565Heinrikson, Meredith, Amino acid analysis by reverse-phase high-performance liquid chromatography: pre column derivatization with phenylisothiocyanate (1984) Analyt. Biochem., 136, p. 65Lucas, Spiders in Brazil (1988) Toxicon, 26, pp. 759-772Paton, A pendulum auxotonic lever (1957) J. Physiol., London, 137, p. 35PRezende, Jr, Cordeiro, Oliveira, Diniz, Isolation of neurotoxic peptides from the venom of the armed spider Phoneutria nigriventer (1991) Toxicon, 29, pp. 1225-1233Schenberg, Pereira-Lima, Pharmacology of the polypeptides from the venom of the spider Phoneutria fera (1966) Mem. Inst. Butantan, 33, pp. 627-638Schenberg, Pereira-Lima, Phoneutria nigriventer venom (1971) Pharmacology and biochemistry of its components, 3, pp. 279-297. , W. Bucherl, E.E. Buckley, Venomous Animals and their Venoms, Academic Press, New YorkShagger, Jagow, Tricine-sodium dodecyl sulfate polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100 kDa (1987) Analytical Biochemistry, 166, pp. 368-379Vane, The use of isolated organs for detecting active substances in the circulating blood (1964) Br. J. Pharmac., 23, pp. 360-373Vital-Brazil, Leite, Fontana, Modo de ação da peçonha da aranha armadeira, Phoneutria nigriventer (Keyserling, 1891), nas aurículas de cobaia (1988) Ciência Cult. (São Paulo), 40, pp. 181-18

Studio in vitro dell\u2019attivit\ue0 antimicrobica di lattobacilli vaginali nei confronti di Chlamydia trachomatis.

INTRODUZIONE E\u2019 noto che un\u2019alterazione del microbioma vaginale con riduzione del numero e della variet\ue0 di lattobacilli \ue8 associata a maggior rischio di infezioni genitali sessualmente trasmesse. Tra queste l\u2019infezione da Chlamydia trachomatis si distingue non solo per l\u2019elevata incidenza, ma anche per la frequenza e la severit\ue0 delle sequele. Pochissimi sono ad oggi gli studi mirati a indagare i meccanismi di interazione tra lattobacilli e Chlamydia. Il nostro studio in vitro si propone di analizzare l\u2019interazione diretta tra diversi ceppi di lattobacilli o loro insieme di metaboliti e i corpi elementari di C. trachomatis prima del loro ingresso nelle cellule (killing extracellulare). METODI Diciassette ceppi di lattobacilli sono stati isolati da tamponi vaginali di donne sane in et\ue0 fertile e coltivati in brodo MRS over-night. Dopo determinazione turbidimetrica della concentrazione di lattobacilli, le colture sono state centrifugate per separare il pellet batterico dal surnatante. Abbiamo quindi messo a contatto i pellet e i corrispettivi surnatanti alle diverse concentrazioni di 5 7107, 5 7106 e 5 7105 con corpi elementari (CE) di Chlamydia, sierotipo D (5 7103 CFU). Sono stati valutati 3 diversi tempi di contatto (7, 15 e 60 minuti) a 37\ub0C. Al termine di ogni incubazione abbiamo centrifugato la sospensione per eliminare le cellule batteriche e inoculato il surnatante contenente i CE in tubini contenenti un vetrino sterile su cui erano state coltivate cellule HeLa a confluenza del 100% circa. Dopo 48 ore di incubazione i vetrini sono stati fissati e colorati con anticorpo monoclonale diretto contro LPS di Chlamydia coniugato con fluoresceina (Meridian, Cincinnati, OH, USA). Abbiamo contato il numero di inclusioni al microscopio a fluorescenza in 30 campi (ingrandimento 200 7) e confrontato i valori medi con quelli di colture cellulari infettate con la stessa quantit\ue0 di CE in assenza di contatto con lattobacilli. I risultati sono stati analizzati con test ANOVA. Un valore di p<0.05 \ue8 stato considerato statisticamente significativo. RISULTATI Abbiamo isolato 8 ceppi di Lactobacillus crispatus (BC1-BC8), 6 di Lactobacillus gasseri (BC9-BC14) e 3 di Lactobacillus vaginalis (BC15-BC17). Tutti i surnatanti eccetto BC10 e BC17 hanno mostrato una riduzione statisticamente significativa di inclusioni alla concentrazione pi\uf9 alta, maggiormente evidente dopo un tempo di contatto di 60 minuti. Tale riduzione non si mantiene per le concentrazioni inferiori. Tra i pellet di lattobacilli vivi nessuno \ue8 stato in grado di ridurre significativamente l\u2019infettivit\ue0 di CT ai tre tempi. CONCLUSIONI I nostri risultati suggeriscono che i lattobacilli giochino un ruolo protettivo nei confronti dell\u2019infettivit\ue0 di CT attraverso la produzione di sostanze rilasciate nell\u2019ambiente circostante piuttosto che attraverso dirette interazioni meccaniche. Tale effetto \ue8 probabilmente ceppo-specifico ed evidente solo ad elevate concentrazioni. Uteriori studi sono in corso per valutare quali siano i metaboliti dei lattobacilli maggiormente implicati nell\u2019azione diretta nei confronti di Chlamydi