ab1904

Stress of chronic food restriction attenuates the development of adjuvant arthritis in male Long Evans rats

J. Jurcovicova, M. Stanciková¹, K. Svík¹, O. Ondrejicková², D. Krsova, J. Seres, R. Rokyta

Department of Normal, Pathological and Clinical Physiology, Third Faculty of Medicine of Charles University, Prague, Czech Republic; ¹Research Institute of Rheumatic Diseases, Piest'any, ²Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovakia.

ABSTRACT
Objective
To study the effect of the stress of chronic food restriction on the development of adjuvant arthritis in Long Evans male rats.

Methods
Four groups of animals were compared: non-treated control (C) and arthritic (AA) rats, both with free access to food and water and two analogous groups with a 40% food restriction, i.e. non-treated (FR) and arthritic (AA-FR) animals. All rats were killed 22 days following the injection of complete Freund's adjuvant. The parameters measured were: serum levels of albumin (ALB), nitrate, glucose, insulin, corticosterone (CORT), prolactin (PRL) and PRL mRNA in the adenopituitaries. In addition the activity of gamma-glutamyl transpeptidase (GGTP) was measured in the spleen. The pain threshold was determined by the tail flick method. The body weight of the animals was recorded on day 0, 3, 7, 11, 15 and 18 of the disease.

Results
Arthritis caused swelling of the hind paw (2.37 ± 0.15 ml vs 1.1 ± 0.05 ml in controls, p < 0.01) which was prevented in the AA-FR group (1.44 ± 0.13 ml, not significant against controls). Arthritis increased serum NO and reduced ALB levels; both changes were significantly restored in the FR-AA group. Food restriction did not alter the activation of GGTP, or the decrease of PRL mRNA observed in the AA group. Serum CORT was elevated in rats with food restriction (15.49 ± 2.1 vs. 3.7 ± 0.87 mg/dL) and remained enhanced to the same extent in AA and FR-AA groups. The tail flick latency prolonged in the AA group was reduced by food restriction.

Conclusion
These results show that 40% food restriction associated with elevated CORT levels mitigated the inflammatory parameters activated during AA.

Key words
Adjuvant arthritis, rat, food restriction, corticosterone, pain threshold.

This work was supported by the Grant Agency of the Czech Republic, Grants No. 605/98/1064 and 605/00/0653.

Please address correspondence and reprint requests to: Jana Jurcovicova, PhD, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlárska 3, 83306 Bratislava, Slovak Republic.
E-mail: ueenjurc@savba.sk