Anterior pituitary (AP) weight, thyroid weight, the serum thyroxine (T4) level, the thyroid T4 and cAMP content, the serum TSH level and the TSH and cAMP content of the AP and thyroid were measured in control rats, rats given methylene blue (MB) in their food, rats given the thyroid-blocking agent carbimazole (CARB) and rats fed both MB and CARB. AP weight fell slightly after MB in both intact and CARB--fed animals. Thyroid weight rose strongly after CARB, MB partly inhibited this increase. The cAMP content of the thyroid rose after CARB; this increase was likewise blocked by MB, MB alone had no effect on the thyroid cAMP concentration. Previous observations showing that MB produced an increase in the blood T, were confirmed. The T4 level fell, of course, after CARB and the decrease was partly inhibited by MB. The T4 content of the thyroid also fell after CARB, this decrease was completely reversed by MB. The blood TSH level fell slightly after MB and rose 7--fold after a CARB blockade of the thyroid; this increase was completely inhibited by MB. The TSH content of the AP fell after MB in both intact and CARB--fed animals. The cAMP content of the AP fell after MB, it was unaffected by CARB. Thus, in some way, MB raised the blood thyroxine level in both intact and CARB--fed animals and strongly depressed the TSH content in the serum and the AP given alone or with CARB. The mechanism of this action should be a result of MB interaction in thyroid hormone metabolism and their binding activity on specific regulatory elements. It is a problem for future experiments.

• MeSH
• adenohypofýza anatomie a histologie   účinky léků   metabolismus   MeSH
• AMP cyklický metabolismus   MeSH
• antidota farmakologie   MeSH
• aplikace orální MeSH
• karbimazol farmakologie   MeSH
• krysa rodu Rattus MeSH
• methylenová modř farmakologie   MeSH
• potkani Wistar MeSH
• radioimunoanalýza MeSH
• štítná žláza anatomie a histologie   účinky léků   metabolismus   MeSH
• thyreostatika farmakologie   MeSH
• thyreotropin metabolismus   MeSH
• thyroxin krev   MeSH
• velikost orgánu účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AMP cyklický MeSH
• antidota MeSH
• karbimazol MeSH
• methylenová modř MeSH
• thyreostatika MeSH
• thyreotropin MeSH
• thyroxin MeSH