Activity of NADH- and NADPH-dependent methemoglobin reductases in erythrocytes from fetal to adult age

Incidence of Variants of Human Red Cell NADH Diaphorase in Japanese Newborns and Coordinate Developmental Changes of Its Activity with Fetal Hemoglobin and F Cells

“…Although Vetrella et al [1971] reported that premature newborns showed activity lower than fullterm ones, the present study did not show significant differences in the enzyme activity between them (table II). However, the slight increase of the enzyme activity was observed in infants in parallel with age.…”

“…It is also described that bismuth nitrite, benzocaine, resorcin or aniline dye produces se vere methemoglobinemia in infants in amounts which cause no abnormality in older individuals [/toss, 1963]. A major cause for such increased susceptibility of infants to acquire methemoglobinemia has been sup posed to be due to very low enzyme activity of red cell NADH diaphorase [Vetrella et al, 1971], An additional factor which makes in fants more susceptible to oxidants may be that fetal hemoglobin (Hb F) can be oxidized more rapidly than adult hemoglobin (Hb A) [Martin and Huisman, 1963], This paper describes the incidence of vari ant isozymes of red cell NADH diaphorase in Japanese newborns and its enzyme activity of infants in development as compared with that of adults. Although we have not found hereditary congenital methemoglobinemia in infants studied this time, we have noticed that increase of enzyme activity during devel opment after birth accompanies decrease of Hb F content and also of the number of F cells, which produce solely Hb F, in the circu lation.…”

Considerations when prescribing trimethoprim-sulfamethoxazole

“…Neonates less than 6 weeks of age, 50 nicotinamide adenine dinucleotidedependent methemoglobin reductase (cytochrome-b 5 reductase) deficiency ing to drug-specific antibodies or T-lymphocyte activation. Simple exanthems and fixed drug eruptions are some of the most common adverse effects of trimethoprim-sulfamethoxazole, occurring in about 3% of hospital inpatients taking the drug.…”

“…50 If there is a strong clinical indication for trimethoprim-sulfamethoxazole therapy in a newborn, it is recommended to start the drug after four to six weeks of age. 58 Although trimethoprim-sulfamethoxazole is detected in breast milk, exposure through breast milk appears to be safe in healthy breastfed infants.…”

Automated determination of red cell methaemoglobin reductase activity by a continuous-flow system for screening hereditary methaemoglobinaemia.

“…We used cord blood to simulate heterozygotes. We believe we are justified in this because heterozygous carriers have methaemoglobin reductase levels about half those of normals (Scott, 1960), and also red cells from cord blood are thought to be weak in their ability to reduce methaemoglobin because of the lower reductase activity in such cells -about half normal levels (Hegesh et al, 1968;Ross, 1963;Vetrella et al, 1971;Kanazawa et al, 1968). Kaplan et al (1970) reported a simple spot screening test for the fast detection of red cell NADHdiaphorase deficiency.…”