[Selective venous sampling of pituitary hormones under provocative tests after retrograde cavernous sinus sinography...

In 22 subjects, selective venous sampling from the inferior petrosal sinus was performed under provocative tests along with simultaneous sampling of pituitary blood from the antecubital vein, after retrograde cavernous sinography. The difference of hormonal levels between sinus blood (Bs) and peripheral blood (Bv) was measured by two antibody radioimmunoassay. Most extreme difference of hormonal levels was observed in acromegalic subjects, where Bs/Bv ratio of GH was 6.0 in the basal value and 4.9 in the peak value, and that of PRL 3.5 and 4.6, respectively. In subjects who reacted to provocative tests, the average ratio of Bs/Bv ranged from 6.9 to 1.1 in the order of GH, PRL, LH, TSH and FSH. Non-reactive subjects showed no significant difference in the hormonal levels between Bs and Bv. From the results obtained above, we assume a possible relationship between Bs/Bv ratio and metabolic clearance rate and between difference of Bs-Bv and basal production. The integral of Bs-Bv difference measured from time zero to the time returned to the basal value under provocative tests represents the sum of basal production and pituitary reserve according to compartment analysis.