it is known that alterations in diet and nutritional status influence immune responses and defense mechamism. Considerable information is available regarding the effect of various stressors on immune functions. However, there is little
information
the
effect of acute food and/or water restriction on immune function, and furthermore there is no information regarding effect of cyclophosphamide (CY) on immune functions of water-and/or food-deprived mice. Thus, this study was undertaken to assess
the
effect of food limitation alone or in combination with CY administration on humoral and cellular immune responses to sheep red blood cells9SRBC0, a thymus-dependent antigen and polyvinylpyrrolidone9PVP), a thymus-independent antigen. Mice were
stressed
by deprivation of food and/or water for 2 days before immunization. CY was administered intraperitonealy as a single dose of 250mg/kg 2s days before immunization. The control mice were fed ad libitum both pellet and water. The humoral immune
response
was evluted by antibody response to SRBC and PVP and cellular immune response was evaluted by SRBC-induced delayed type hypersensitivity(DTH) reactions and contact hypersensitivity to dinitrofluorobenzene(DNFB). It was revealed that CY given
250mg/kg
before immunization significantly enhanced contact hypersensitivity to DNFB and DTH reactions to SRBC in normal unstressed mice, but significantly inhibited antibody response to SRBC and PVP. The water and/or food deprivation for 2 days
signigicantly
enyhanced contact hypersensitivity to DNFB and DTH reactions, but inhibited the primary antibody response to SRBC and caused no alteratin in the secondary antibody response. The food and water restriction with or without CY administration did not
influence the anti-PVP anti-body response except that water deprivation alone or in combination with CY administration increased the response. Interestingly, CY further augmented the enhanced contact hypersensitivity caused by water and food
deprivation
suggesting the suppressor cell may play an important role in immunomodulation in limit-feeding mice, but did not enhance or inhibit 24 hr-DTH reationin limit-feeding mice. However, CY did not reverse the depression of the primary anti-SRBC
antibody
response caused by water and/or food deprivation. Taken together, these results indicate that water and/or food deprivation for 2 days before imjmunization significantly may enhance the contact hypersensitivity to DNFB and DTH reaction to SRBC,
and
that
in contrast the cellular immune response, the primary antibody response to SRBC were inhibited, but the secondary response to SRBC were not affected by water or food deprivation, and the anti-PVP antibody response was exceptionally enhanced by
water
deprivation. Furthermore, this study also provide the initial evidence that CY may augment the enhanced contact hypersensitivity caused by water and/or food deprivation.
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