Bird hypoxia and low heart rate protection by CR

[Guest guest]

Hi All,

The effect of CR on blood pressure was described in

Swoap SJ, Weinshenker D, Palmiter RD, Garber G.

Dbh(-/-) mice are hypotensive, have altered circadian rhythms, and have abnormal

responses to dieting and stress.

Am J Physiol Regul Integr Comp Physiol. 2004 Jan;286(1):R108-13. Epub 2003 Sep

11.

PMID: 12969876

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=12969876 & query_hl=7

http://tinyurl.com/ccx77

of a full-text-available to all paper. Also, heart rate was a component of the

reduced blood pressure of CR. A new paper suggests the opposite response in

heart

rate during CR and hypoxia, in which the heart rate is abnormally slowed.

Ascites

production was the hypoxia-inducing condition.

First, for definitions, see:

ascites: An effusion and accumulation of serous fluid in the abdominal cavity.

serous: Thin; watery; like serum; as the serous fluids. Of or pertaining to

serum;

as, the serous glands, membranes, layers.

serous gland: An exocrine gland that produces a watery, protein rich secretion,

as

opposed to a carbohydrate rich mucous secretion.

tachycardia: The excessive rapidity in the action of the heart, the term is

usually

applied to a heart rate above 100 per minute and may be qualified as atrial,

junctional (nodal) or ventricular and as paroxysmal.

bradycardia: A slowness of the heart beat, as evidenced by slowing of the pulse

rate to less than 60 beats per minute.

See the not pdf-available below suggesting that the bradycardia seen in poultry

during the hypoxia of ascites is protected from by CR via inducing the normal

tachycardia of ascites.

Currie RJ.

Ascites in poultry: recent investigations.

Avian Pathol. 1999 Aug;28(4):313-26.

PMID: 16147559

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=16147559 & query_hl=3

.... Broilers that subsequently develop ascites, exhibit lower heart rates than

their

normal flock mates. Furthermore, during ascites, hypoxic broilers exhibit

bradycardia as opposed to the expected tachycardia. In these cases, a

tachycardia

induced by feed restriction may protect the bird by raising its cardiac output.

....

Al Pater, PhD; email: old542000@...

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