7/29/2019 Serum Magnesium Changes in Hibernation

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Riedesel, Ilarvinchanges in

L" and G. Edgar Foltrc, Jr. 1956" Serum magnesium

hibernation. Nature 177: 668

(Reprinted lrom Nature, Vol. 177, p. 668 only, Aptil 1, 1956)This research was aided by grants from the Oentral

Sciontific Furrd of the College of Medicine, StatoUniversity of fowa, and National Science Foundation,Washington, D.C.

Menvtw L. Rrnonsrr,G. Eosen Fon, JtrN.

Department of Occupational Health,University of Pittsburgh,

Pittsburgh, Penn.,and

Department of Physiology,State tTniversity of Iowa,

Iowa City, Iowa.Dec. 6.

r Suomalainen. P., Ann. Acad. Sci,. Fennicae, A, 53, 1 (1939). ?latner,W. W., and Eosko, M, J., Amer. J. Phusiol.,174, 273 (195!).

McBirnie, K, E,, Pehrson, ii. c., Trusler,G. A:, Karachi, E.8.,and Bigelow, W. G., Canad,. J, Med. Sci.,81, 42f (1935)., Natelson, S,, and ?enniall, P"., AnaI. Chem,,22,434 (1955).3 Orange, M,, and B,hein, tr. C., J. Biol, Chem.,189, 379 (1951),

Printcd in Great Britain bv Fishcr, Knicht & co., Ltd.' st. Albaos.

Serum Magnesium Changes inHibernation

Ilrrrotnnnura. and hibernation have been subjoctsof increasing interest in recent years, yet there is a

critical lack of obsorvations on the biochemistry oftheso states. Iligh levels of magnesium in serumhave boon related by several investigators to hiberna'tion and cold erposurel. In the present, studies

levels of serum magnesium and other electrolytes,and sorum spocific gravities, wore comp&red in bats

in sevoral seiies including both hibernating and non'hibernating conditions.

The first species (Eptesictts fuscus) was collectedin hibernation in a cave. One.group was trled v'hilostill dormant and the other group after they were

maintained a,nd fed in a flight cage for four days.

The socond species (Mgotis lucifugus) was obtainodfrom a sufiImor colony and from & cave in winterhibornation. The spocimens were bled after periods

of hibernation varying from I hr. to 9 weeks. The

serum potassium detorminations by flame photometryshowed no significant changos due to hibernat'ion.For other oloctrolytes recently described micro-mothods were used; for the calcium, the method ofNatelson and Penniallr and for magnesium themethod of Orange and R'hein!. Tho serum calcium-level during hibernation decreased, whereas thecell/plasnra iatio and the specific gravity of the serumincreased slightly but, not consistently. Tho serummagnosium in all hibernating gloups wgs f0 per cent

higher than in the active animals, which normallyshowed a level of 4'1 mgm. per 100 ml. P valuesranged frorn 2 to less tha,rr I por cont. The specific'gravity rosult's indicatod t'his was not a passivo

o"ftT:";"r"*eof serum magnesium in bats occurred

after only one to two hours of hibernation and was

found by the time the esophageal temperature haddropped to 13'C. There was no significant increase

in serum magnesium when the esophageal t'empera-

ture had dropped to only t?-20'C. Awakening from

hibernation does not require a lowering of the serum

magnesium, since there was no reduction of serum

magnesium when bodS' temperaturo was.raised

to

l8'-C., a procedure which required 5-8 min. IIow'over, one hour after arousal from hibernation, the

sorurn magnesium had dropped. The incroase inseru- magnesium in hibornation is uninfluenced byseaaon.