B-type natriuretic peptide (BNP) serum levels in rats after forced repeated swimming stress.
OBJECTIVE
To estimate the effects of forced repeated swimming stress on BNP serum levels in rats.


METHODS
Adult male Wistar rats weighting between 280-330 g were divided into two groups: control group (n = 8) and stress group (n = 8). Rats in the stress group were exposed to forced swimming stress daily, for 7 days. The rats were forced to swim in plastic tanks (90 cm wide, 120 cm deep) containing tap water (temperature ca. 25 degrees C). The depth of water was 40 cm. Duration of each swimming session progressively increased from 10 minutes on the first day to 40 minutes on days 6 and 7. Rats were sacrificed and blood was drawn from abdominal aorta for BNP analysis immediately after the last swimming session. B-type natriuretic serum level was determined by ELISA method using RAT BNP-32 kit (Phoenix Pharmaceutical Inc.).


RESULTS
There was no statistically significant difference between mean BNP serum level in the stress group after the swimming period (0.81 +/- 0.14 ng/ml) as compared to the unstressed group of rats (0.8 +/- 0.08 ng/ml). After the swimming period mean body weight slightly decreased in the stress group in comparison with values before stress period (296.3 g vs. 272.8 g), but this difference was not statistically significant. The stress period had no influence on food intake in the stress rat group.


CONCLUSIONS
The workload consisting of 40-minutes long swimming session is not sufficient to provoke BNP release from myocardium in rats.
Department of Physiology, School of Medicine, University of Sarajevo, Bosnia and Herzegovina. fiziologija.09@gmail.com
Almira
A
Hadzovic-Dzuvo
Amina
A
Valjevac
Nesina
N
Avdagić
Orhan
O
Lepara
Asija
A
Zaćiragić
Radivoj
R
Jadrić
Jasmin
J
Alajbegović
Besim
B
Prnjavorac
D000818:Animals; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D005082:Physical Exertion; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological; D013550:Swimming
D020097:Natriuretic Peptide, Brain