Contribution of portal-drained viscera to heat production in Iberian gilts fed a low-protein diet: comparison to Landrace.

BACKGROUND: In terms of whole-body metabolism, visceral tissues have a disproportionate influence with respect to their masses, and under certain circumstances their high metabolic rate may compromise nutrient availability to the tissues of productive/economic interest. The low energy efficiency of Iberian compared to modern breeds could be partly explained by the contribution of portal-drained viscera to heat production. The objective of this study was to determine the relative contribution of portal-drained viscera heat production (PDVHP) to total heat production (THP) in Iberian and Landrace gilts fed a diet with low protein content. RESULTS: Compared to Landrace, Iberian gilts (29 ± 0.9 kg body weight) had lower pre- and postprandial portal vein blood flow (654 vs. 965, and 746 vs. 1133 mL min(-1) , respectively; P < 0.01), postprandial PDVHP (3.09 vs. 3.88 kJ h(-1) kg(-0.75) ; P < 0.01) and PDVHP/THP ratio (0.08 vs. 0.13; P < 0.05), and greater THP (38.5 vs. 31.8 kJ h(-1) kg(-0.75) ; P < 0.05), when offered 0.25 of their daily ration in a 6 h sampling period. CONCLUSION: In spite of the low energetic efficiency and growth rate of Iberian compared to modern breeds, the contribution of PDV energy expenditure relative to THP was lower in Iberian compared to Landrace gilts in the present study.

The comparative abilities of propofol and sevoflurane to modulate inflammation and oxidative stress in the kidney after aortic cross-clamping.

BACKGROUND: Propofol has been reported to provide protection against ischemia-reperfusion injury. Nuclear transcription factor kappa B (NFkappaB) plays a key role in oxidative stress and the inflammatory response during ischemia-reperfusion. We compared the effect of propofol with sevoflurane on kidney NFkappaB expression and systemic inflammatory responses induced by aortic clamping. METHODS: Twenty piglets were divided into four groups: sham surgery group with propofol (group SP, n = 5); sham group with sevoflurane (group SS, n = 5); and suprarenal clamping for 30 min with aorta-aortic bypass under propofol (group CP, n = 5) or sevoflurane (group CS, n = 5) anesthesia. Propofol was administered at 4 mg x kg(-1) x h(-1) i.v. and sevoflurane given at 1.5% inspiratory concentration. Peripheral blood and kidney biopsies were taken before the start of surgery, 15 min after unclamping the aorta, 24, 48, 72 h, and 7 days after surgery. Plasma creatinine, myeloperoxidase, tumor necrosis factor-alpha, interleukin 1-beta; and kidney superoxide anion and superoxidase dismutase were measured. The expression of inducible nitric oxide synthase and renal tissue NFkappaB was measured using Western blotting. RESULTS: Compared with the CS group, animals in the CP group had lower concentrations of myeloperoxidase, tumor necrosis factor-alpha, interleukin 1beta, superoxide anion, superoxidase dismutase (P < 0.05) from 24 to 72 h after surgery and diminished NFkappaB expression and inducible nitric oxide synthase activity (P < 0.05) at 48 and 72 h after surgery, respectively. CONCLUSIONS: Compared with sevoflurane, propofol administration during suprarenal aortic clamping and unclamping led to modulation of markers of inflammation and decreased NFkappaB expression.

Laboratory investigation: effects of propofol on the systemic inflammatory response during aortic surgery.

PURPOSE: A laboratory investigation was undertaken to assess the effects of propofol on renal function, through modulation of the systemic inflammatory response, in an in vivo experimental model of aortic surgery in comparison with sevoflurane. METHODS: Twenty young male piglets were anesthetized with either propofol 4 mg.kg(-1).hr(-1) (n = 10) or sevoflurane 1.5% end-tidal concentration (n = 10). Animals were subjected to aorta-aortic bypass with suprarenal aortic clamping for 30 min. At specific intervals (basal -before the start of surgery; reperfusion 15 min after unclamping the aorta; at 24, 48 and 72 hr after surgery, and on the seventh day after surgery) the levels of the following were determined: plasma creatinine, renal myeloperoxidase, tumour necrosis factor-alpha, interleukin 1-ss, and interferon-gamma; kidney superoxide anion and its detoxifying enzyme superoxidase dismutase, kidney malondialdehyde and the activity of inducible nitric oxide synthase. Seven days after surgery, the animals were anesthetized using the described techniques, and after blood withdrawal and kidney sampling they were sacrificed. RESULTS: In comparison with sevoflurane, propofol was associated with a lower concentration of plasma creatinine (P < 0.05) together with lower concentrations of myeloperoxidase, tumour necrosis factor-alpha, interleukin 1-ss, interferon-gamma, superoxide anion and superoxidase dismutase, malondialdehyde and inducible nitric oxide synthase (P < 0.05). CONCLUSION: In an experimental model of aortic reconstructive surgery, and compared with sevoflurane, propofol anesthesia is associated with less neutrophil infiltration, lower plasma proinflammatory cytokine levels, lower production of oxygen free radicals, less lipid peroxidation, and reduced inducible nitric oxide synthase activity. These observations suggest a possible renal protective effect of propofol in this surgical setting.