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We measured the corticosterone and dihydrotestosterone steroid binding capacities of corticosteroid-binding globulin (CBG) and sex steroid plasma binding protein (SBP) throughout pregnancy in seven Macaca nemestrina. The nSBP binding capacity rises significantly by 28 days of pregnancy, remains elevated through 56 days, tends to fall through midpregnancy, and then decreases dramatically to very low values 130-153 days after conception. In contrast, nCBG rises slightly (1.2-fold) in early pregnancy, is elevated in midpregnancy, but is similar to nonpregnant values during the last trimester of pregnancy. Our data indicate that factors controlling the plasma concentration of nCBG and nSBP are not identical. The results are in sharp contrast to those observed in human pregnancies in which both hSBP and hCBG are increased severalfold during pregnancy, including at term. Because the changes of nCBG and nSBP during pregnancy do not paralle the changes observed in human beings even though their steroid binding characteristics are similar, the M. nemestrina may serve as a valuable model for defining the physiologic function of SBP and CBG and the mechanism(s) controlling their concentrations in blood.

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We describe a new method of interpreting platelet aggregometry results and its correlation to platelet secretory protein levels. We studied 123 healthy male volunteers, 37-85 years of age. The aggregation response to 2.5 μM ADP was measured in a standardized platelet suspension (SPS) prepared from platelet-rich plasma. Turbidimetic measurements included amplitude of the primary aggregation wave (Amp1), maximum aggregation amplitude (Amax), and area under the aggregation curve (Sagg). A platelet aggregation (PA) score was calculated as ( Amp1 /Amax) ·Sagg ·(whole-blood platelet count/SPS platelet count). β-Thromboglobulin (β-TG)and . platelet factor 4 (PF4) levels were measured by radioimmunoassay. The PA score correlated significantly (p < 0.0001) with β-TG ( r = 0.86) and PF4 ( r = 0.87). It was concluded that the PA score correlates closely with individual subjects' propensities to platelet activation, as reflected by plasma β-TG and PF4 levels. Key Words: Platelets-Platelet aggregometry-Platelet secretory proteins.