Changes of IgE production in senescence-accelerated mice SAMP8.

The IgE production and proliferation activity of spleen B cells were studied in vivo in 2 approximately 3-month-old (designated as young) and 12 approximately 13-month-old (designated as old) senescence-accelerated mice (SAMP8) employing age-matched AKR mice, the origin of the SAM strain, as controls. After the secondary immunization with 2,4-dinitrophenylovalbumin conjugate (DNP-OVA) with aluminum hydroxide gel (alum) as an adjuvant, the serum IgE levels were significantly reduced in old SAMP8 compared to young SAMP8 mice, but there were no changes in AKR. However, old SAMP8 mice had a proliferative activity of spleen B cells comparable to that found in young SAMP8; proliferative activity was measured by 3H-thymidine incorporation into the spleen after stimulation with water extract from wood chips of coniferous splash pine (pine wood extract) as a mitogen. These data indicate that a decline in IgE production is a characteristic phenomenon of SAMP8 mice and was not due to the functional deficiency of B cells with aging.