Solubilization of Sodium Channel from Human Brain

in Journal of Neurochemistry (1989), 52(2), 349-53

[3H]Tetrodotoxin binds to a single class of receptor sites in homogenates of human brain with a KD of 9.1 nM at 0 degree C and a maximal binding capacity of 5.9 pmol/mg of protein. This tetrodotoxin ... [more ▼]

[3H]Tetrodotoxin binds to a single class of receptor sites in homogenates of human brain with a KD of 9.1 nM at 0 degree C and a maximal binding capacity of 5.9 pmol/mg of protein. This tetrodotoxin receptor has been solubilized, and several parameters influencing the efficiency of this critical step have been studied. Treatment of brain membranes with 2% (wt/vol) Nonidet P-40 solubilizes up to 38% of the tetrodotoxin receptor sites. The duration of this solubilization step must not exceed 15 min at an optimal pH of 6.8. The binding activity is most stable when exogenous phosphatidylcholine is added to the soluble receptor with a phosphatidylcholine/detergent ratio of 1:5. [less ▲]

Antibodies to laminin in preeclampsia.

in Kidney International (1986), 29(5), 1050-57

Laminin is a large basement membrane glycoprotein localized in the trophoblast, glomerular basement membrane and in the mesangial matrix of human glomeruli. It promotes the attachment of epithelial cells ... [more ▼]

Laminin is a large basement membrane glycoprotein localized in the trophoblast, glomerular basement membrane and in the mesangial matrix of human glomeruli. It promotes the attachment of epithelial cells to basement membrane collagen. We have found that 14 sera from 52 patients with severe preeclampsia or eclampsia contain IgG and IgM antibodies which react with placental and kidney basement membranes. These antibodies were specific for laminin and did not react with other basement membrane proteins. They were able to fix complement. They have been demonstrated by radial immunodiffusion, radioimmunoassay and immunofluorescence blocking studies. In primary cultures they were shown to impair the attachment of trophoblast cells to basement membrane collagen. High levels of circulating immune complexes were detected only in sera from preeclamptic patients with circulating antibodies to laminin. The auto-antibodies to laminin could play a major role in the pathogenesis of severe preeclampsia by impairing the attachment of trophoblast cells to placental basement membranes and by fixation to the glomerular basement membranes and mesangial matrix. [less ▲]

Membrane associated thiamine phosphatases in the electric organ of Electrophorus electricus

Poster (1985, September 03)

Effects of androgens and oestrogens on the behaviour of chicks in an imprinting situation.

in Zeitschrift für Tierpsychologie (1979), 49(1), 55-64

The behavioural effects of testosterone propionate (TP), 5alpha-dihydrotestosterone (DHT) and oestradiol benzoate (OB) were investigated in day-old chicks during imprinting sessions to a duck model. TP ... [more ▼]

The behavioural effects of testosterone propionate (TP), 5alpha-dihydrotestosterone (DHT) and oestradiol benzoate (OB) were investigated in day-old chicks during imprinting sessions to a duck model. TP increased the duration of peeping while inhibiting the following reaction and the twitters. DHT had more or less the same effects while OB induces the reverse behavioural changes. The behavioural effects of hormone injections agree with behavioural sex differences observed in non-injected animals: males peep more than females which on the other hand produce more twitters. This could be related to sex differences in the hormonal status of the birds at hatching, as it is known that during incubation male chick embryos have higher plasma testosterone levels than females of corresponding ages. [less ▲]