Effects of spermidine treatment on neurobehavioral development in intrauterine growth retarded (IUGR) rats.

It was previously shown that polyamine treatment could induce precocious development of several somatic and neurobehavioral functions in newborn rats. This study investigates the effects of daily injections of spermidine (SPMD) 50 microl/10 g s.c. on neurobehavioral development of newborn rats experiencing undernutrition. Neurobehavioral development was assessed by measurements of gripping and righting reflexes. SPMD treated intrauterine growth retarded (IUGR) rats reached righting reflex control values at 30 days postnatal (1.87 +/- 0.78 s vs 1.75 +/- 0.66 s). Beginning from 7 days postnatal, gripping reflex values of SPMD treated IUGR rats declined, reaching that of controls at 30 days postnatal (1.77 +/- 91 degrees vs 1.82 +/- 65 degrees). These results suggest the utility of exogenous SPMD in rats experiencing undernutrition, thus indicating a clinical relevance.

Effect of dietary n-3 fatty acid deficiency on blood-to-brain transfer of sucrose, alpha-aminoisobutyric acid and phenylalanine in the rat.

Possible alterations in blood-to-brain unidirectional transport of sucrose (mol. wt., 342), alpha-aminoisobutyric acid (mol. wt., 104), and L-phenylalanine (mol. wt., 165) induced by a diet deficient in n-3 polyunsaturated fatty acids were studied with respect to blood-brain barrier function. Two groups of rats were for to two generations with a semisynthetic diet. One group of rats was fed a peanut oil+rapeseed oil diet which contained both essential fatty acids: linoleic acid (18:2 n-6) and alpha-linolenic acid, (18:3 n-3). Another group was fed a diet of peanut oil, this diet (containing 18:2 n-6) was deficient in alpha-linolenic acid. The experiments were performed at 6 months of age. Unidirectional transfer rate constants (Ki) of sucrose, alpha-aminoisobutyric acid and L-phenylalanine were measured. The diet based on peanut oil (deficient in n-3) caused a greater blood-to-brain transport of sucrose but not of alpha-aminoisobutyric acid or L-phenylalanine. These observations indicate that regardless of the mechanisms involved, alterations in essential fatty acids induced by diet can modulate to some extent the blood-brain transport of hydrophilic molecules without a carrier.

Brain uptake of a food dye, erythrosin B, prevented by plasma protein binding.

Although food colors have been held responsible for several behavioral disorders and do affect neuronal function when directly applied, there is no information on whether significant quantities of the dyes appear in the brain after consumption or parenteral administration. [14C]erythrosin B was administered directly into the circulation of mature rats and radioactivity was measured thereafter in brain regions at several times. Although insignificant parenchymal radioactivity was detected in brains perfused with dye in whole blood, significant concentrations of [14C]erythrosin B were detected in all brain regions when perfused with protein-free Ringers, as predicted from the octanol-water partition coefficient of the dye. Thus, significant brain uptake of intravascular dye is normally prevented by its binding to plasma protein (greater than 99% bound) and by the blood-brain barrier impermeability to the dye-protein complex. Sensitivity to food dyes such as erythrosin B in some individuals may reflect altered plasma protein binding capacity, which can vary with age and disease.