Effect of methallibure (ICI 33,828) on the pituitary-gonad and the pituitary-thyroid axes of the Indian garden lizard, Calotes versicolor (Daudin).

The effect of methallibure (ICI 33,828) on the pituitary-gonad and the pituitary-thyroid axes of the Indian garden lizard, Calotes veriscolor was studied. Following administration of methallibure B2 (FSH) and B3 (ICSH) cells of the pars distalis exhibited significant alterations with concomitant changes in the seminiferous tubules, and in the interstitial cells and epididymis respectively. B1 (TSH) cells exhibited conspicuous hypertrophy and degranulation which was reflected in dramatic changes in thyroid morphology. The caudally localized acidophilic A1 (PRL) cells also showed hypertrophy, hyperplasia and intense granulation. The rostrally located A2 (STH) acidophils and the B4 (ACTH) cells were unaffected by the treatment. The possible model of action of this drug is discussed in the light of available literature.