GB824375A - Respiration-stimulant substances from blood - Google Patents

Abstract

A process for the preparation of a respiration-stimulating active substance comprises subjecting the blood of slaughter-animals to dialysis to effect substantially complete deproteination and to effect complete removal of protein particles having a molecular weight in excess of approximately 3000 therefrom and concentrating the dialysate thereby obtained to a dry content of 10-60 mg/ml., preferably at least 30 mg/ml. The dialysis is preferably effected in a tube of "Cellophane" (Registered Trade Mark) employing as solvents water or dilute alcohol. Prior to dialysis the blood may be subjected to a preliminary deproteination by fractional precipitation with alcohols, e.g. straight or branched chain aliphatic alcohols containing from 1-6 carbon atoms or acid such as trichloracetic acid or preferably perchloric acid. The concentrated dialysate may be purified by precipitation with aliphatic ketones or alcohols containing from 1-6 carbon atoms, acetone being a particularly useful precipitant, or by extraction with a water-immiscible or partly immiscible solvent such as aliphatic alcohols with 3-8 carbon atoms, e.g. butanol, or aliphatic ethers with 2-12 carbon atoms and both resulting phases worked up. Preferably the blood is subjected to a pretreatment before dialysis or before the preliminary deproteination preceding dialysis, such as haemolysis, treatment with acetone, spray-drying, defibrination, peptic and/or tryptic digestion. The crude concentrate and/or purified concentrate may be evaporated to dryness, dissolved in distilled water and sterile filtered and freeze-dried under sterile conditions. Phenol and cresol may be added as preservatives. The crude concentrate after sterile filtration can be applied directly. The blood used is preferably that of young slaughter-animals and may come from animals which have been put into a condition of altered activity by mechanical or chemical treatment or by irradiation. Blood-cells and plasma may be separated and worked up separately.