False-positive results may occur in BIPSS when the serum cortisol levels are not high enough to suppress the corticotroph cells in cases of cyclic or mild CS and periodic hormonogenesis
from ectopic sources (22,23).
The pathogenesis of AIH is related to a failure to escape from the acute Wolff-Chaikoff effect due to defects in thyroid hormonogenesis.
The Jod-Basedow phenomenon is an increase in synthesis of T4 and T3 due to exposure to large amounts of iodine, which provides increased substrate available for thyroid hormonogenesis.
CH affects about 1 in 3,000 to 1 in 4,000 infants and in about 15% of cases may result from a defect of thyroid hormonogenesis
, mostly inherited in an autosomal recessive fashion (Vulsma and de Vijlder 2000).
5-7) In the latter circumstance, TSH levels may be in the normal range, but the lack of a nocturnal rise in TSH results in impaired thyroid hormonogenesis
, possibly due to a decrease in the daily mass of TSH secreted by the pituitary gland.
Ascorbic acid, an easily diffusible water-soluble biologic reductant, is found in abundance in testes (32), where it plays an important role in testicular hormonogenesis (33).
Low level of plasma testosterone may be due to a direct effect of nickel on the testicular hormonogenesis, which is supported by the decrease in steroidogenic enzyme activities with a concomitant increase in cholesterol and ascorbic acid levels (Table 4, Figures 2 and 3).