Effect of fasting duration on clinical pathology results in Wistar rats.
BACKGROUND
Fasting is an important preanalytical factor that may affect the interpretation of hematology and clinical biochemistry data in toxicology or pharmacology studies. Limited information is available on how the results may be affected by different durations of fasting.


OBJECTIVE
The purpose of this study was to assess the influence of fasting duration on clinical pathology results in male and female rats and to determine an optimum fasting time for preclinical studies.


METHODS
Male and female Wistar rats (10 each per group) were fasted for 0, 4, 8, 16, 24, and 48 hours. Changes in body weight and in the results of routine CBC and clinical chemistry analysis were evaluated by 1-way ANOVA.


RESULTS
Body weight was significantly decreased by 4 hours of fasting in all rats, and hemoglobin concentration was significantly increased at 16 hours in male rats. Serum glucose and triglyceride concentrations in both sexes and cholesterol and high-density lipoprotein-C concentrations in female rats were also significantly decreased beginning at 16 hours. The creatinine concentration was increased in females after 16 hours of fasting. Serum alkaline phosphatase and alanine aminotransferase activities were significantly decreased after 8 hours in males and 16 hours in females.


CONCLUSIONS
Fasting-induced changes in clinical pathology results were consistent with hemoconcentration and altered nutrition and metabolic function. Most changes occurred at 16 hours, with minimal subsequent changes. Hence, a 16-hour fasting duration may be recommended for preclinical studies involving clinical pathology measurements.
Department of Pharmacology and Toxicology, Zydus Research Centre, Ahmedabad, Gujarat, India.
Vijay P
VP
Kale
Girish S
GS
Joshi
Parikshit B
PB
Gohil
Mukul R
MR
Jain
D000818:Animals; D001772:Blood Cell Count; D004734:Energy Metabolism; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D006454:Hemoglobins; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D013997:Time Factors; D015431:Weight Loss
D006454:Hemoglobins