Abstract
Ultracentrifugal determinations of serum lipoproteins were carried out in 16 subjects including 3 normal and 13 leprosy cases (macular tuberculoid " maculo-anaesthetic by Indian workers"…1, minor tuberculoid…5, lepromatous leprosy…7). All the case were free of complications as nephritis, atherosclerosis, tuberculosis and lepra reaction. Twenty-five ml.of fasting venous blood was collected by venepuncture without use of an anticoagulant and serum separatd by clotting. The density of the serum was increased to 1.063 by addition of sodium chloride in a proportion of 100mg. per ml. of serum. The serum was then spun at 40, 000 r.p.m. in a Hitachi preparative ultracentrifuge (40 P-type) for 8 hours (71, 500∼107, 000×g) at a temperature of -5°C. One ml. of the top fraction (flotation layer) was carefully removed. Paper electrophoretic studies showed that this fraction consisted of a large amount of β-lipoprotein and a small amount of α2-lipoprotein. Next 0.3ml. of the fraction was diluted 4-fold with 2 Mol NaC1 and analytical ultracen- trif ugation carried out. All analytical runs were made at a rotor speed of 59, 52059, 840 r.p.m. in a cell of 0.8ml. capacity at 13.427.3°C with the Spinco Model E ultracentri- fuge. The serum of the maculo-anaesthetic case showed a lipoprotein of the Sf 11.4 class (1 Sf=1 Svedberg unit of flotation =10-13cm. /sec./dyne/g.) and a molecular weight of about 395, 000. No significant difference was found between the serum lipoprotein of the healthy subject and the maculo-anaesthetic patient. The serum lipoprotein Sf of minortuberculoid leprosy was in the 9.2∼11.1 class with a mean of 10.3 and a calculated molecular weight of about 330, 000. Differing from the maculo-anaesthetic or minor tubercu- loid leprosy, the serum lipoprotein of lepromatous leprosy was made up of several flotation classes of differing Sf. This trend is observed in nodular cases according to the Madrid classification. The Sf in lepromatous leprosy showed a wide variation of from 3.4 to 13.7 with a mean of 6.6 and the molecular weight was found to be close to 173, 000.
