This study was carried out to determine whether the prophylactic injection of
glucocorticoid into the intracerebroventricular (i.c.v.) space reduced
TNF-alpha and IL-1beta
mRNA synthesis in the brain after
laparotomy, resulting in a reduction of
nitrogen excretion in the urine.
PATIENTS AND METHODS: Male SD rats (body wt., 225-250 g, n = 114) were catheterized into the i.c.v. space on day 0. On day 4, the rats were assigned to four groups: (1) Control, (2)
laparotomy (
Trauma), (3) intraperitoneal (i.p.) injection of
methylprednisolone (MP) plus
laparotomy (IPMP), and (4) i.c.v. injection of MP plus
laparotomy (ICVMP). Either 3 or 24 h after surgery, the animals were sacrificed.
TNF-alpha and IL-1beta
mRNA levels in tissues, including the brain cortex and hypothalamus, were measured by RT-PCR. The amounts of
nitrogen and
catecholamine excretion in the 24-h urine were determined.
RESULTS: The i.p. injection of MP reduced
TNF-alpha and IL-1beta
mRNA levels in all the tissues 3 h after
laparotomy compared with those of the
Trauma group. The icv injection of MP prevented elevation of the
TNF-alpha and IL-1beta
mRNA levels in the brain (cortex,
TNF-alpha, ICVMP 0.43 +/- 0.06, P < 0.05, vs
Trauma; cortex, IL-1beta, ICVMP 0.25 +/- 0.09, P < 0.05, vs.
Trauma; hypothalamus,
TNF-alpha, ICVMP 0.31 +/- 0.04, P < 0.05, vs.
Trauma; hypothalamus, IL-1beta, ICVMP 0.25 +/- 0.14, P < 0.05, vs.
Trauma), but did not inhibit an increase in
TNF-alpha and IL-1beta
mRNA levels in the liver and skeletal muscle. Both
nitrogen and
catecholamine excretions in the urine were decreased by ip and by i.c.v. injection of MP compared to those of the
Trauma group (
nitrogen, ICVMP 559.3 +/- 52.0 mg/day, P < 0.05, vs.
Trauma;
catecholamine, ICVMP 13.8 +/- 1.8 microg/day, P < 0.05, vs.
Trauma).
CONCLUSION: