Effects of caffeine on anterior pituitary and thyroid function in the rat

E. Spindel, M. Arnold, B. Cusak, R. J. Wurtman

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


We studied the effects of acute, intraperitoneal administration of caffeine on serum thyrotropin (TSH), growth hormone, prolactin, thyroxine and 3,3',5-triiodothyronine in rats. Caffeine lowered serum TSH and GH in a dose-dependent manner with ED50 values of 30 and approximately 50 mg/kg, respectively. TSH levels were depressed 1 to 6 hr after injection and correlated with serum caffeine levels greater than 20 μg/ml. The decrease in serum TSH was followed by decreases in serum 3,3',5-triiodothyroxine and thyroxine 4 hr after caffeine administration. Theophylline and theobromine had effects similar to those of caffeine on hormone levels. Caffeine did not significantly affect hormone secretion when incubated directly with rat pituitaries in vitro. Administration of antisomatostatin antiserum to rats blocked the inhibitory effects of caffeine on serum GH levels, suggesting that caffeine inhibits GH and TSH secretion by releasing hypothalamic somatostatin.

Original languageEnglish (US)
Pages (from-to)58-62
Number of pages5
JournalJournal of Pharmacology and Experimental Therapeutics
Issue number1
StatePublished - 1980
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology


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