Search

Levels of thyroid hormones (T,T) in serum and cyclic adenosine 3′, 5′-monophosphate (cAMP) and cyclic guanosine 3′, 5′-monophosphate (cGMP) in plasma were successively determined in 77 patients with hyperthyroidism before and 1, 2, 3, 6 months afteriodine (I) treatment. Before treatment, the levels of total serum T, T and plasma cAMP of all of the patients were higher than normal, while the level of plasma cGMP was lower than normal (P<0.0l). The patients were divided into 3 groups: A, B, C, according to the clinical features and serum levels of T, T 3-6 months after treatment. Group A (18 patients) clinically showed no improvement, T, T still remained higher than normal and cAMP, cGMP revealed no significant change in comparison with the pretreatment state. Group B (45 patients) clinically showed marked improvement, their thyroid toxic symptoms practically subsided, T, T gradually turned to normal and concentration of cAMP and cGMP subsequently reached normal level. Group C (14 patients) presented temporary hypothyroidic features; their level of T, T fell below the normal range, while the concentration of plasma cAMP and cGMP approached the level contrary to the state before treatment. Since the change of T and T occurred synchronously, the question of whether T or T exerted an influence on plasma cyclic nucleotides concentration and the interrelationship between thyroid hormones and cyclic nucleotides as well as the significance of plasma cAMP and cGMP in pathogenesis and therapy of hyperthyroidism remains to be further elucidated. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the levels of testis tissue cyclic nucleotides and plasma testosterone in testis-irradiated rats with saturation analysis 1-52 days after 676 rad and 7 days after 290-1930 rad. It was found that ionizing radiation of a given dose scale did not affect significantly the excretion of testosterone. An initial rise of cyclic adenosine monophosphate (cAMP) was probably associated with an increase of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) excretion and a decrease of cAMP in the later stage was possibly due to the depletion of the germ cells, following irradiation less than 965 rad. The reduction of cAMP after 1930 rad was probably related to direct inhibition of the larger dose of cAMP production. These results suggest that the levels of cAMP after irradiation can reflect the degree of testis radiation injury. In addition, it was also found that ionizing radiation failed to change the testis cyclic guanosine monophosphate (cGMP) levels, suggesting the presence in testis of only a 'one-way' regulation carried out by cAMP. [ABSTRACT FROM AUTHOR]