Folate-deficiency induced cell-specific changes in the distribution of lymphocytes and granulocytes in rats.
OBJECTIVE
Folate (vitamin B(9)) plays key roles in cell growth and proliferation through regulating the synthesis and stabilization of DNA and RNA, and its deficiency leads to lymphocytopenia and granulocytopenia. However, precisely how folate deficiency affects the distribution of a variety of white blood cell subsets, including the minor population of basophils, and the cell specificity of the effects remain unclear. Therefore, we examined the effects of a folate-deficient diet on the circulating number of lymphocyte subsets [T-lymphocytes, B-lymphocytes, and natural killer (NK) cells] and granulocyte subsets (neutrophils, eosinophils, and basophils) in rats.


METHODS
Rats were divided into two groups, with one receiving the folate-deficient diet (FAD group) and the other a control diet (CON group). All rats were pair-fed for 8 weeks.


RESULTS
Plasma folate level was dramatically lower in the FAD group than in the CON group, and the level of homocysteine in the plasma, a predictor of folate deficiency was significantly higher in the FAD group than in the CON group. The number of T-lymphocytes, B-lymphocytes, and NK cells was significantly lower in the FAD group than in the CON group by 0.73-, 0.49-, and 0.70-fold, respectively, indicating that B-lymphocytes are more sensitive to folate deficiency than the other lymphocyte subsets. As expected, the number of neutrophils and eosinophils was significantly lower in the FAD group than in the CON group. However, the number of basophils, the least common type of granulocyte, showed transiently an increasing tendency in the FAD group as compared with the CON group.


CONCLUSIONS
These results suggest that folate deficiency induces lymphocytopenia and granulocytopenia in a cell-specific manner.
Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan.
Ikumi
I
Abe
Ken
K
Shirato
Yoko
Y
Hashizume
Ryosuke
R
Mitsuhashi
Ayumu
A
Kobayashi
Chikako
C
Shiono
Shogo
S
Sato
Kaoru
K
Tachiyashiki
Kazuhiko
K
Imaizumi
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D005494:Folic Acid Deficiency / Q000097:blood* / Q000209:etiology; D006098:Granulocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006403:Hematologic Tests; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016131:Lymphocyte Subsets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley