Modulation of insulin receptors and catecholamines in rat brain in hyperthyroidism and hypothyroidism.
Insulin receptor activity and its relationship with catecholamines and serotonin were investigated in rat brain using Triton X-100 extracts from total membranes, synaptosomes and choroid plexus in experimental hypothyroidism and hyperthyroidism. Insulin receptor activity was assessed by binding to [125I]insulin and catecholamines by high performance liquid chromatography. In choroid plexus thyronines effects are well pronounced and there is modulation vis a vis plasma hormone concentrations. Triiodothyronine levels increase in brain in all experimental groups. This suggests that rat may serve as a useful model for thyronine homeostasis in brain and there may be involvement of very complex regulatory mechanisms in glucose tolerance.
School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
M
M
Azam
N Z
NZ
Baquer
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006980:Hyperthyroidism / Q000378:metabolism*; D007037:Hypothyroidism / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011972:Receptor, Insulin / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
D002395:Catecholamines; D007328:Insulin; D014284:Triiodothyronine; D012701:Serotonin; D011972:Receptor, Insulin