Synthesis of physalaemin

Riassunto Per condensazione fra fenilalanil-tirosilglicil-leucil-metioninamide e N-carbo-ter-butossi-piroglutammil- alanil - - ter -butil -aspartial -prolil -asparaginil -{ie492-1}-carbo-ter-butossi-lisina in presenza di dicicloesilcarbodiimmide si è ottenuto l'endecapeptide VIII che per trattamento con una soluzione di HCl in acido trifluoroacetico ha fornito la piroglutammil-alanil-aspartilprolil-asparaginil-lisil-fenilalanil-tirosil-glicil-leucil-metioninamide identica, per proprietà chimiche, fisiche e biologiche alla physalaemina naturale.     

Structure and pharmacological actions of physalaemin,the main active polypeptide of the skin ofPhysalaemus fuscumaculatus

Riassunto Viene descritto il procedimento che ha permesso l'isolamento e il chiarimento della struttura chimica dellafisalemina, il principale dei polipeptidi attivi della pelle diPhysalaemus fuscumaculatus, anfibio dell'Argentina. La fisalemina, strettamente vicina all'eledoisina anche da un punto di vista chimico è, come questa, dotata di potente azione sulla muscolatura liscia vasale ed extravasale. Essa è nettamente distinguibile, mediante saggi paralleli, da tutti gli altri polipeptidi biogeni finora noti.

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Supported in part by a grant from the Consiglio Nazionale delle Richerche, Roma.     

Effects of physalaemin,a vase-active peptide from amphibian skin,on the excitability of an identifiable molluscan giant neurone ofAchatina fulica Férussac

Summary We examined effects of several vasoactive peptides (substance P, physalaemin, neurotensin, bradykinin, angiotensin etc.) on the excitability of molluscan giant neurones identified in the subesophageal ganglia ofAchatina fulica Férussac. Of these peptides, only physalaemin showed a remarkable excitatory effect on a giant tonically autoactive neurone.     

Occurrence of an eledoisin-like polypeptide (physalaemin) in skin extracts ofPhysalaemus fuscumaculatus

Riassunto Gli estratti di pelle fresca o secca diPhysalaemus fuscumaculatus contengono una sostanza attiva di natura polipeptidica, laphysalaemina, dotata di potente azione ipotensiva e di intensa azione stimolante su alcuni muscoli lisci extravasali. La physalaemina è facilmente distinguibile, mediante saggi paralleli, da tutti gli altri polipeptidi biogeni finora noti, compresa la eledoisina che alla physalaemina s'accosta per parecchie delle sue azioni farmacologiche.

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Supported by grants from the Consiglio Nazionale delle Ricerche, Roma, and the Rockefeller Foundation, New York.     

SV40 transformed fibroblasts recognize the same 140 kD fibronectin chemotactic fragment as non-transformed cells

SV40-virus-transformed human embryonal fibroblasts show an enhanced chemotactic response to the glycoprotein fibronectin. However, they recognize the same chemotactic active region as non-transformed fibroblasts. The result suggests that an enhancement of chemotaxis by fibroblasts which have been transformed with Simian Virus 40 is due not to the utilization of further chemotactic domains in the molecule, but to an increased sensitivity of the cells to the chemoattractant.     

SV40 transformed fibroblasts recognize the same 140 kD fibronectin chemotactic fragment as non-transformed cells

Summary SV40 virus-transformed human embryonal fibroblasts show an enhanced chemotactic response to the glycoprotein fibronectin. However, they recognize the same chemotactic active region as non-transformed fibroblasts. The result suggests that an enhancement of chemotaxis by fibroblasts which have been transformed with Simian Virus 40 is due not to the utilization of further chemotactic domains in the molecule, but to an increased sensitivity of the cells to the chemoattractant.     

Inhibitory effect of beta-hydroxyglutamic acid on a molluscan giant neurone.

We found a spontaneously firing neurone, inhibited by beta-hydroxy(erythro)-L-glutamic acid, identified in the subesophageal ganglia of an African giant snail (Achatina fulica Férussac), although this neurone is not sensitive to L-glutamic acid. We suggest that beta-hydroxy(erythro)-L-glutamic acid may be a putative inhibitory synaptic transmitter of the identified molluscan neurone.     

Inhibitory action of serum from a Laron dwarf on normal cellular function

Glucose uptake and O2 consumption of confluent glial cells grown in culture were measured in the presence of serum-free buffer and compared with those measured in the presence of serum from a normal volunteer, from an hGH-deficient dwarf and from a Laron dwarf. Cellular glucose uptake and respiration in the absence or presence of insulin or hGH are inhibited by Laron serum.     

Inhibitory effect of bacterial ubiquinones on the settling of barnacle,Balanus amphitrite

In an attempt to clarify the influence of marine bacteria on the settling of fouling invertebrate larvae, we screened for inhibitors, produced by marine bacteria, of settling by cyprids of the barnacle,Balamus amphitrite. We found that the culture broth ofAlteromonas sp. strain number KK10304, which was associated with the marine sponge,Halichondria okadai, effectively inhibited settling of the cyprids. Bioassay-guided isolation indicated ubiquinone-8 (1) as an effective inhibitor of cyprid settling. As ubiquinones are widely distributed in bacteria, several related compounds were also tested.     

2-Carboxyethylgermanium sesquioxide,a synthetic organogermanium compound,as an inducer of contrasuppressor T cells

2-Carboxyethylgermanium sesquioxide (Ge-132), a synthesized organogermanium compound with immunomodulaing activities, was shown to be an inducer of anti-suppressor T cells in normal mice. The suppressor cell activity of T6S cells, a clone of burn-induced CD8⁺ IL-4-producing suppressor T cells, was clearly inhibited when a mixed lymphocyte-tumor cell reaction of the clone was conducted with splenic mononuclear cells from mice treated orally with a 100 mg/kg dose of Ge-132. The activity of anti-suppressor cells was demonstrated in spleens of mice 2 days after treatment with Ge-132 and reached its peak on day 3. The anti-suppressor cells induced by the compound were of a contrasuppressor T cell-linage, because they were characterized as CD4⁺ CD28⁺ TCR/⁺ Vicia villosa lectin-adherent T cells. These cells produced IFN- but did not produce IL-2, IL-4, IL-6 or IL-10 in their culture fluids. CD4⁺ anti-suppressor T cells induced by Ge-132 may be different from other subsets of CD4⁺ T cells because Th1 and Th2 cells generated in our laboratory did not adhere toVicia villosa lectin-coated petri dishes, and each produced specific cytokines. Th1 cells produced IFN- and IL-2 while Th2 cells produce IL-4 and IL-10 in vitro. These results suggest that Ge-132 may be useful as an inducer of contrasuppressor T cells in immunocompromised individuals bearing suppressor T cells. To eliminate suppressor T cells from immunocompromised hosts may result in improved resistance from various opportunistic infections.     

Anti-bovine beta-lactoglobulin antibodies react with a human lactoferrin fragment and bovine beta-lactoglobulin present in human milk

Human milk samples react against anti-bovine beta-lactoglobulin rabbit antibodies, as measured by a competitive radioimmunoassay. Immunoreactivity was positive even in milk from mothers consuming a diet free of cow's milk. An increase with a diet rich in cow's milk proteins was detected by immunoelectrophoresis. The human milk fraction cross-reacting with anti-bovine beta-lactoglobulin antibodies corresponds to the 20 kDa fragment from the N-terminal end of human lactoferrin. Three regions of this fragment exhibit sequence homology with a sequence contained in cow's beta-lactoglobulin (between residues 124 and 141).