Effects of hormone replacement therapy on serum amyloid P component in postmenopausal women.

The pentraxin serum amyloid P component (SAP) is a 9.5Sz1-glycoprotein and it has recently been found to be deposited in atherosclerotic lesions or neurofibrillary tangles, which are related to the aging process and Alzheimer's disease. The level of SAP was measured by micro single radial-immunodiffusion. Sample sera were obtained from 420 healthy humans, from newborn to 86 years old. The changes in SAP during the menstrual cycle were investigated in 6 women that were 20-21 years. Fifty of the postmenopausal women, suffering from climacteric symptoms, were administered either conjugated estrogen (E), or dehydroepiandrosterone (DHEA). The SAP levels increased with age, being 1.12 +/- 0.82 mg/dl (means +/- S.D.) in neonates, and 6.15 +/- 0.92 mg/dl in persons over 80 years. The SAP level in the females between 15 and 49 years (3.32 +/- 0.95 mg/dl) was significantly (P < 0.001) lower than that in the males in the same age group (5.19 +/- 1.25 mg/dl). The SAP level in the follicular phase was significantly (P < 0.01) lower than that in menstrual phase (menstrual: 4.36 +/- 0.90 mg/dl versus follicular: 2.61 +/- 0.99 mg/dl). In the post-menopausal women that were administered E (1.25 mg/day), the SAP decreased significantly (P < 0.001) from the prelevel of 5.64 +/- 1.40 mg/dl to 4.26 +/- 0.98 mg/dl on the 14th day. In the postmenopausal women that were administered DHEA (60 mg/day), the SAP increased rapidly from the prelevel of 4.97 +/- 0.76 mg/dl to 6.17 +/- 1.20 mg/dl on the 21st day. SAP seems to be a marker that can monitor the effect of hormone replacement therapy.