Experiments Concerning the Renal Clearances of Some Fructosans in the Dog

Abstract

A PRELIMINARY communication [Beattie and Corcoran, 1949] reported that the renal clearances of two fructosans, one levan isolated from Italian rye grass (Lolium italicurn) and the other irisin isolated from the rhizomes of the common yellow flag iris (Iris pseudacoruts), declined with time. These results have been confirmed and extended in a later paper [Beattie and Corcoran, 1952] [1925] from iris rhizomes grown in Essex, England.B. The two bacterial levans were isolated from the growth media of the appropriate micro-organisms. The medium consisted of sterile 20 per cent glucose solution mixed under sterile conditions with an equal quantitv of sterile solution containing peptone, 0-2 per cent, Na2HPO4.2H20, 0-4 per cent, KCI, 1b0 per cent, and a small crystal of ferrous sulphate. When the production of polysaccharide appeared to be well advanced, saturated barium acetate was added to the medium maintaining a pH of 8*2-8-15, until no further precipitate was formed. The

Molecular inhomogeneity as a source of error in inulin clearance studies

“…Artichoke inulin gave a value different from either of these. A similar decrease in clearance rate was observed in the dog by Beattie & Bell (1953), after the intravenous injection of fructosans which had been shown, by ethanol precipitation and other physico-chemical means, to exhibit molecular inhomogeneity. If the inulin injected were heterogeneous with respect to molecular size, and assuming simple glomerular filtration, we should expect the different particle sizes to be excreted in the urine at different rates.…”