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Biomedical subjects

M L Maayan

Publications and source records attributed to M L Maayan.

32 records · Page 2Linked to original sources
PubMed1977

TSH and catecholamines: independent effects on active transport and iodine organification in isolated thyroid cells.

Catecholamines greatly stimulated iodine organification in thyroid cells isolated by trypsinization but failed to increase the cell-medium (C/M) ratio of 131I- or 99mTcO4- in the same cells preparation. Both TSH and catecholamines increased the concentration of organified iodine in thyroid cell despite the presence of active transport inhibitors, suggesting either the existence of a second thyroidal transport system or the possibility of an accelerated entry of anions into thyroid cells in the presence of stimulatory agents.

Animals↗
PubMed1977

Gold thioglucose obesity syndrome.

Parenteral administration of gold thioglucose to mice produces an area or necrosis in the ventromedial portion of the hypothalamus. The lesion, like lesions produced by electrocautery of this area, causes hyperphagia and consequent obesity. The glucose moiety of gold thioglucose is essential for production of the lesion. Glucose analogues (2-deoxy-glucose, sodium thioglucose and phlorizin) prevent the gold thioglucose-induced lesion, and by themselves produce a transient hyperphagia. Insulin deficiency prevents the lesion. Either adrenalectomy or hypophysectomy counteracts the effect of insulin deficiency. Electron microscopic studies, in which general necrosis is avoided by administration of aspirin before gold thioglucose or by administration of subnecrotic doses of gold thioglucose, reveal that gold thioglucose primarily affects neural elements contiguous with capillaries in the ventromedial hypothalamus. The experimental observations indicate the presence of special glucoreceptor cells in the ventromedial hypothalamus that are involved in the regulation of food intake.

Adrenalectomy↗
PubMed1968

Epinephrine: effect on uptake of iodine by dispersed cells of calf thyroid gland.

In isolated thyroid cells I-epinephrine (0.1 and 10.0 micrograms per milliliter), norepinephrine and isoproterenol consistently stimulated the accumulation and organic binding of iodine. The effect was partially inhibited by phentolamine, but not propranolol, and hence may be mediated by alpha receptors. Theophylline did not mimic or enhance the epinephrine effect, suggesting that the latter may not result from activation of adenyl cyclase.

Adenylyl Cyclases↗