Effect of prophylactic intracerebroventricular injection of methylprednisolone on nitrogen and catecholamine excretion in the urine after laparotomy in rats.
BACKGROUND
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.


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).


CONCLUSIONS
A reduction in TNF-alpha and IL-1beta mRNA synthesis in the brain due to prophylactic injection of MP into the icv space reduced the catabolic response after laparotomy.
Tajiri
Tetsuro
T
Department of Surgery, School of Medicine, Kurume University, 67 Asahi-machi, Kurume, Fukuoka, 830-0011, Japan.
Yoshida
Shogo
S
Ishibashi
Nobuya
N
Tanaka
Katsuaki
K
Muraoka
Tatsuya
T
Shirouzu
Kazuo
K
D000818:Animals; D002395:Catecholamines / Q000652:urine*; D002540:Cerebral Cortex / Q000737:chemistry; D015870:Gene Expression; D007031:Hypothalamus / Q000737:chemistry; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000235:genetics; D007813:Laparotomy; D007958:Leukocyte Count; D008099:Liver / Q000737:chemistry; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage*; D018482:Muscle, Skeletal / Q000737:chemistry; D009584:Nitrogen / Q000652:urine*; D011183:Postoperative Complications / Q000517:prevention & control; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D002395:Catecholamines; D007375:Interleukin-1; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D009584:Nitrogen; D008775:Methylprednisolone