Pyridine nucleotides in the thyroid

Pyridine Nucleotides in the Thyroid Gland. VIII. Effect of Thyroid-Stimulating Hormone on Nicotinic Acid-14C Incorporation Into NAD, NADP and NADPH

“…There are three possible mechanisms either singly or in combination which could account for an increase of NADP in slices, namely: 1) stimulation of new synthesis catalyzed by the enzyme NAD kinase, 2) stimulation of NADPH oxidation; and 3) inhibition of degradation of NADP. As stated in previous reports (2,12,13), stimulation of NAD kinase by TSH was considered to be more likely since the increase in NADP was associated with an equivalent decrease in NAD. Furthermore, the reduced levels of NADPH were not sufficient to account for the augmented NADP.…”

“…Furthermore, the reduced levels of NADPH were not sufficient to account for the augmented NADP. However, direct and clear-cut evidence for stimulation of NAD kinase by TSH was not obtained in those experiments (12,13). The present experiments, which demonstrate elevated NADP within 10 minutes of the addition of TSH before there is increased incorporation of nicotinic acid-14 C into NADP, suggest that this effect is not due to stimulation of NAD kinase ( Table 1).…”