Rifkind A B, Sassa S, Merkatz I R, Winchester R, Harber L, Kappas A
J Clin Invest. 1974 Apr;53(4):1167-77. doi: 10.1172/JCI107655.
Human sera were found to contain factors that stimulate and factors that inhibit porphyrin formation by cultured avian liver cells. The capacity of sera to stimulate or inhibit porphyrin formation varied in different hormonal states and in the porphyrias. Sera from 31 post partum women, eight of whom were not lactating, inhibited porphyrin formation to a mean level 30% below the level in control cultures and also inhibited drug and steroid stimulation of porphyrin formation. In contrast, mean porphyrin formation compared to control cultures was increased between 9 and 21% by sera from 52 normal subjects, 16 women on oral contraceptives, and 11 pregnant women. It was increased 193% by sera from nine subjects with acute intermittent porphyria and 172% by sera from 13 subjects with porphyria cutanea tarda. Heated sera or ethanol extracts of sera from all groups of subjects further increased the mean porphyrin stimulation by sera and, for the post partum subjects, eliminated the inhibitory effect. Ethanol extracts of sera from 28 oral contraceptive-treated women caused significantly greater mean stimulation of porphyrin formation than did extracts of sera from 30 normal women. While sera from 17 out of 22 porphyric subjects contained both stimulatory and inhibitory factors, 5 out of 22 had no evidence of an inhibitory component. There appeared to be heterogeneity in the occurrence of the factors among porphyrics.The factor(s) in sera responsible for porphyrin stimulation were heat-stable and insensitive to trypsin; were present in the supernates after ethanol precipitation of plasma proteins; were extractable in ethyl acetate and nondialyzable; and they migrated with the albumincontaining fraction of serum during electrophoresis. The factor(s) responsible for porphyrin inhibition were heat labile, sensitive to trypsin, and resistant to neuraminidase; were present in the ethanol precipitates of sera and were nondialyzable; and they migrated with the gamma globulin fraction of serum during electrophoresis. Inhibition of porphyrin formation was not attributable to heme, free or bound as hemoglobin, hemopexin, or hemalbumin.
人们发现，人血清中含有刺激培养的禽肝细胞卟啉形成的因子和抑制卟啉形成的因子。血清刺激或抑制卟啉形成的能力在不同的激素状态和卟啉症中有所不同。31名产后妇女的血清，其中8名未哺乳，抑制卟啉形成的平均水平比对照培养物中的水平低30%，并且还抑制药物和类固醇对卟啉形成的刺激。相比之下，52名正常受试者、16名口服避孕药的妇女和11名孕妇的血清与对照培养物相比，平均卟啉形成增加了9%至21%。9名急性间歇性卟啉症患者的血清使其增加了193%，13名迟发性皮肤卟啉症患者的血清使其增加了172%。所有受试者组的加热血清或血清乙醇提取物进一步增加了血清对卟啉的平均刺激作用，对于产后受试者，消除了抑制作用。28名口服避孕药治疗妇女的血清乙醇提取物对卟啉形成的平均刺激作用明显大于30名正常妇女的血清提取物。虽然22名卟啉症患者中有17名的血清含有刺激和抑制因子，但22名中有5名没有抑制成分的证据。卟啉症患者中这些因子的出现似乎存在异质性。血清中负责卟啉刺激的因子对热稳定且对胰蛋白酶不敏感；存在于血浆蛋白乙醇沉淀后的上清液中；可在乙酸乙酯中提取且不可透析；并且在电泳过程中与血清中含白蛋白的部分一起迁移。负责卟啉抑制的因子对热不稳定，对胰蛋白酶敏感，对神经氨酸酶有抗性；存在于血清的乙醇沉淀物中且不可透析；并且在电泳过程中与血清的γ球蛋白部分一起迁移。卟啉形成的抑制并非归因于游离的或与血红蛋白、血红素结合蛋白或血红蛋白白蛋白结合的血红素。
