Hemoglobin changes during metamorphosis in Triturus viridescens

Pharmacologic hemoglobin reversal: the importance of lipid intermediaries and the proposed involvement of the cAMP and phosphatidylinositol second messenger systems

Humoral and microenvironmental influences have played a major role in recent research into reversing the Hb F to Hb A switch. Early research in this area focused on hormonal influences and showed both thyroid hormone and prolactin could induce small but statistically significant reversals in hemoglobin phenotype. Recent research has focused on the effect of certain lipids in this process. The current study shows a synergy between thyroid hormone and prolactin in inducing a significant switch in adult rat hemoglobin patterns toward the neonatal pattern. Further, it is hypothesized that this synergy is due to the hormones' effect on lipid intermediaries whose effect in turn are proposed to be mediated by the cAMP and phosphatidylinositol second messenger systems.

Multiple hemoglobins in Triturus cristatus: their study by analytical isoelectrofocusing

Electrophoretic separation of the hemoglobin of healthy adult Triturus cristatus reveals four components. Isoelectric focusing of the same hemolysates in various commercial ampholytes of different chemical composition and pH range results in the separation of eight individual hemoglobin bands. The bands obtained by electrophoresis are not homogeneous as revealed by individual gel electrofocusing. They finally separate into the same eight components, as in the whole hemolysate. From the above findings it is concluded that this species has not four but eight individual hemoglobin molecular forms. Our results demonstrate lack of hemoglobin polymorphism in this species.

Comparison of hemoglobins from the genus Xenopus (Amphibia salienta)

A survey of the electrophoretic mobility of hemoglobins of 14 species and subspecies of the genus Xenopus was undertaken. It was found that the variation between the different taxons considered was quite important in the number and the degree of the hemoglobin bands on polyacrylamide slab gels. The profiles of the hemoglobin electrophoretic pattern in tube gels gave corresponding results, confirming the variation between the different Xenopus species. The degree of resolution obtained on polyacrylamide slab gels was insufficient to allow one to distinguish between the subspecies of Xenopus laevis. Specific staining of the gels showed that the protein bands were in fact hemoglobins. From the results obtained it appears that there are relative differences in the number and mobility of hemoglobin bands between the different species, these differences being important enough to stimulate interest in further investigation in this field, but, as far as this preliminary investigation indicates, not clear-cut enough to use as a method of identification for isolated unknown species.

Multiple hemoglobins in Triturus cristatus: their degradation by sulfhydryl compounds

1. Hemolysates of newt (Triturus cristatus) red cells contain four distinct hemoglobin species which have been observed consistently both in individual animals and pooled samples. 2. Hemoglobin heterogeneity in the species arises from existence of multiple hemoglobulins, with no indication of genetic polymorphism. 3. While the relative proportions of the different hemoglobins may vary in different samples, HbII is usually the most abundant, with HbIII and HbIV constituting most of the remainder of the total hemoglobin complement. HbI never exceeds 3-5% of the total hemoglobin. 4. Neither the electrophoretic migration nor the anion exchange properties of the four hemoglobin species are altered by conversion of oxyhemoglobin to the cyanmet derivative, excluding artifacts due to different oxidation states of iron. 5. The average molecular weight of newt total hemoglobulin is 67,182 with no indication of hemoglobin polymers. 6. The use of sulfhydryl-reducing agents (mercaptoethanol, dithiothreitol) as a precaution against aggregation results in extensive degradation of newt hemoglobin through a process similar to "coupled oxidation" by ascorbate. 7. The degradative effects of sulfhydryl-reducing agents on newt hemoglobin suggest that these reagents be used cautiously in any hemoglobin analysis.

Studies of the development of frog hemopoietic tissue in vitro. I. Spleen culture assay of an erythropoietic factor in anemic frog blood

A new in vitro technique has been described for demonstrating the presence of an erythropoietic factor in the circulating blood of frogs. The assay system consisted of MC33 medium, erythropoietically active spleen cells from Rana pipiens, and plasma or serum from frogs made anemic via phenylhydrazine or bleeding. The spleen cells, which remain erythropoietically active for up to nine days, were found to incorporate 59Fe, [3H]thymidine, [3H]uridine, and [3H]leucine at a greater rate in the presence of plasma or serum from anemic versus normal frogs. The hormones triiodothyronine, prolactin, and erythropoietin were not effective in eliciting an hemopoietic response. The data presented suggest that the spleen from that adult frog is a major site of erythroid differentiation and maturation.