Oral and intraperitoneal administration of N-acetylneuraminic acid: effect on rat cerebral and cerebellar N-acetylneuraminic acid.

Rat pups were administered N-acetylneuraminic acid (NANA) by i.p. injection or via a feeding catheter for eight consecutive days beginning on d 14 of life. All pups were given the identical dose: 1.0 mg on d 1 and 2 and 1.2 mg on the remaining days, or approximately 20 mg/kg body weight per day. A control group was injected i.p. with glucose instead of NANA. On the morning of d 25, pups were decapitated, and the heads were frozen immediately in liquid nitrogen. The brains were later dissected and analyzed for both cerebral and cerebellar ganglioside and glycoprotein NANA. Administration of NANA by both oral and i.p. routes resulted in significantly more cerebral and cerebellar ganglioside and glycoprotein NANA than did glucose injection (with the exception of cerebellar glycoprotein NANA after NANA intubation). There were no significant differences in NANA concentration in these brain fractions for the two routes of NANA administration.