Full resolution (JPEG) - On this page / på denna sida - V. The Blood - II. The Form-elements of the Blood - Blood-pigments
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
METH.EMOGOBLV OYANMETHiEMOGLOBIN. 285
ammonia. The a l»<>rpt ion-spectrum of a watery or acidified solution
of met haemoglobin is, according to Jaderholm and Bertin-Sans, very
similar to that of haematin in acid solution, but is easily distinguished
from the latter since, on the addition of a little alkali and a reducing
substance, the former passes over to the spectrum of reduced haemoglobin,
while a haematin solution under the same conditions gives the spectrum
of an alkaline haemochromogen solution (see below). According to
Araki and Dittrich, a neutral or faintly acid methaemoglobin solution
shows only one characteristic band, a, between C and D, whose middle
corresponds to about X = 634. The two bands between D and E are
only due to contamination with oxyhsemoglobin (Menzies, Lewin,
Miethe and Stenger. According to Hasselbach’s l
experience a
pure neutral solution of methaemoglobin gives four absorption bands cor-
responding to a maxima X = 630, 580, 540 and 500. Methaemoglobin
in alkaline solution shows two absorption-bands which are like the
two oxyhaemoglobin bands, but they differ from these in that the band
/S is stronger than a. By the side of the band a and united with it by a
shadow lies a third fainter band between C and D, near to D. (Spec-
trum Plate, 4.)
The claims as to the action of sodium fluoride upon haemoglobin and methaemo-
globin are somewhat contradictory. 2
Crystallized methaemoglobin may be easily obtained by treating a
concentrated solution of oxyhemoglobin with a sufficient quantity of
concentrated potassium-ferricyanide solution to give the mixture a porter-
brown color. After cooling to 0° C. add cne-fourth vol. cooled alcohol
and allow the mixture to stand a few days in the cold. The crystals
may be easily purified by recrystallizing from water by the addition
of alcohol. According to Hasselbach this method ordinarily gives
imnure products while a pure preparation can be obtained by the action
of i^ht (see above).
Cyanmethaemoglobin (cyanhaemoglobin) is, according to Haldaxe. identical
with photomethaemoglobin (Bock), which is produced by the influence of sun-
light upon a methaemoglobin solution containing potassium ferricyanide. It
wu- first carefully described by R. Robert and obtained in a crystalline form
by v. Zeyxek. 3
It is immediately formed in the cold by the action of a hydro-
cyanic-acid solution upon methaemoglobin, but is formed by its action upon oxy-
1
Jaderholm, Zeitschr. f. Biol. 16; Bertin-Sans. Comp. Rend., 106; Araki, Zeitschr. f.
physiol. Chem., 14; Dittrich. Arch. f. exp. Path. u. Pharm.. 29: Menzies, Journ. of
Physiol., 17; Lewin and collaborators, footnote 1, page 282: Hasselbach, Bioch.
Zeitschr., 19, and Proceedings of the 7th Internat. Congr. of Appl. Chem., London,
1909. Important references on methaemoglobin are given by Otto, Pfluger’s Arch., 31.
2
Piettre and Vila, Compt. Rend., 140; Ville and Derrien, ibid., 140.
3
Haldane, Journ. of Physiol., 25; Bock, Skand. Arch. f. Physiol., 6: Robert,
Pfluger’s Arch.. 82; v. Zeynek, Zeitschr. f. physiol. Chem., 33. See also Leers,
Biochem. Zeitschr., 12.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
