Abstract
Populations living in goitre endemic areas consume foods rich in a variety of goitrogens of di}erent potencies and some are severely hypothyroid[ Recently we observed in Wistar:NIN rats that chronic feeding of KSCN to dams produced only a moderate hypothyroidism and decreased the transport of 1!deoxy!D!glucose "1!DG# across the blood!brain barrier "BBB# in the o}spring[ The present studies were conducted to assess whether severe hypothyroidism would have greater e}ect on BBB nutrient transport[ It has now been observed that weaning the pups of KSCN fed dams on to KSCN diet for four weeks had no further e}ect either on their thyroid status or the BBB 1!DG transport[ However feeding KSCN to rats through two generations produced somewhat severe hypothyroidism in F1 pups than that in F0 pups[ Interestingly unlike in F0 pups the BBB transport of all the three nutrients tested "1!DG Leu and Tyr# was signi_cantly decreased in F1 pups albeit to a small extent "09Ð04)#[ On the other hand the potent goitrogen] methyl mercaptoimidazole "MMI# even on short term feeding to pregnant dams produced very severe hypothyroidism in the o}spring ðSerum T3]9[4429[98 mg:dl vs 3[8529[74 in controlsŁ[ Surprisingly the BBB transport of 1!DG Leu Tyr and also sucrose the background marker was signi_cantly increased in these pups "19Ð29)#[ The diverse e}ects of goitrogen!induced moderate and severe hypothyroidism observed here on the BBB nutrient transport probably suggest di}erent mechanisms for iodine de_ciency disorders of di}erent aetiologies and hence the need for discrete approaches for their management[ Þ 0887 Elsevier Science Ltd[ All rights reserved[