Frank A. Rawlins

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A procedure that allows areas up to 1 cm2 of the epithelium to be separated from the corium of the toad skin is described. For several hours the preparation maintains the transport characteristics of the isolated intact skin, namely electrical potential differences up to 100 mV (outer side negative) and short-circuit currents up to 80 μAmp/cm2, which are(More)
A time-sequence study of the incorporation and distribution of cholesterol in peripheral nerve myelin was carried out by electron microscope autoradiography. [1,2-(3)H]Cholesterol was injected into 10-day old mice and the sciatic nerves were dissected out at 10, 20, 40, 60, 90, 120, and 180 min after the injection. 20 min after injection the higher(More)
In the doubly perfused toad kidney, lanthanum ions were included in the perfusion fluid in a soluble form and were subsequently precipitated as anthanum sulfate. The precipitate was localized by electronmicroscopy. Precipitate was mainly observed at the tight junctions and in the intercellular spaces. Practically no lanthanum was observed within the cells.(More)
The effect of two inhibitors of cholesterol biosynthesis, triparanol and AY 9944, on peripheral nerve myelination, was studied. Suckling mice were intraperitoneally injected with both drugs on 3 consecutive days and were sacrificed 6 hr after the last injection; others were suckled by an injected mother and sacrificed at 2(1/2) days of age. A single mouse(More)
The localization of (3)H-labeled cholesterol in nerves undergoing degeneration and regeneration was studied by radioautography at the electron microscope level. Two types of experiments were carried out: (a) Cholesterol-1,2-(3)H was injected intraperitoneally into suckling mice. 5 wk later, Wallerian degeneration was induced in the middle branch of the(More)
The paracellular pathway permeability is known to increase in perfused amphibian kidneys if the luminal fluid is made hyperosmotic with mannitol or urea. To investigate whether luminal hypertonicity increases paracellular pathway permeability in the mammalian nephron, early rat distal tubules were micropunctured and perfused through one micropipette with(More)
Intact and slit nerve fibers of the squid Sepioteuthis sepioidea were incubated in a 50-nM solution of [125I] alpha-bungarotoxin in artificial seawater, in the absence and in the presence of D-tubocurarine (10(-4) M). The distribution of the radioactive label was then determined by electron microscope autoradiography. It was found that, in the fibers(More)