Laparoscopic vs. open abdominal surgery in male pigs: marked differences in cortisol and catecholamine response depending on the size of surgical incision.

OBJECTIVE: Minimally invasive operations, such as laparoscopic cholecystectomy and adrenalectomy, result in a more rapid recovery of normal function, less physiological disturbances and less stress to the organism than similar open operations. The purpose of this study was to determine the stress response associated with minimally invasive abdominal surgery compared to conventional small or large incision laparotomy. METHODS: We compared the responses of the stress hormones cortisol and the catecholamines adrenaline and noradrenaline to elective conventional and laparoscopic cholecystectomy and unilateral adrenalectomy in male pigs. Blood samples were taken from all animals at the same time, one day before surgery, at the beginning of the operation, every 15 minutes during surgery and on the first postoperative morning. RESULTS: Plasma adrenaline and noradrenaline concentrations were significantly lower in both cholecystectomies (p<0.05) and adrenalectomies (p<0.01) during laparoscopic than during open surgery. Plasma cortisol levels were significantly lower in laparoscopic than in open adrenalectomies both during surgery and on postoperative day one (p<0.05), while no major differences in cortisol levels were observed between laparoscopic and open cholecystectomies. Thus, the stress-related benefit of laparoscopic surgery depended on the size of the surgical incision in the conventional operation. CONCLUSION: Laparoscopic surgery was associated with less surgical stress than open surgery and this difference was accentuated as the surgical abdominal wall trauma increased.

Terazosin treatment suppresses basic fibroblast growth factor expression in the rat ventral prostate.

PURPOSE: Alpha1-adrenergic receptor antagonists may not act solely on smooth muscle contractility. We evaluated the in vivo effect of the alpha1 blocker, terazosin, on the expression of basic fibroblast growth factor (bFGF) in the rat ventral prostate. METHODS: Wistar rats were treated with terazosin (1.2 mg/kg body weight, po, every second day) for 120 days. The expression of bFGF was assessed immuno-histochemically in tissue sections and by Western blotting in whole tissue preparations. RESULTS: Terazosin treatment did not affect prostate weight or histomorphology. In the control group, epithelial and stromal cells demonstrated positive staining for the anti-bFGF antibody. In contrast, the same staining in terazosin-treated specimens was either absent or extremely weak. An analogous difference was observed among the corresponding immunoblots. CONCLUSIONS: These findings implicate the reduction of bFGF expression by terazosin as a potential additional molecular mechanism of its action that may include alterations in peptide growth factor mediated prostate homeostasis.

Hypothyroidism and the aorta. evidence of increased oxidative DNA damage to the aorta of hypothyroid rats.

BACKGROUND: Although it has been suggested that the hypometabolic state is associated with a decrease in oxidative stress, literature data are controversial, revealing an individuality of oxidant status in relation to tissue properties and responsiveness. Hypothyroidism has profound direct and indirect actions on the vascular system, inducing characteristic hemodynamic changes while the aorta represents an important determinant of vascular performance. This study aims to examine the oxidant status on the aorta in chronic experimental hypothyroidism. MATERIALS AND METHODS: Chronic hypothyroidism was successfully induced in 20 male Wistar rats by administration of 0.05% 6-n-propyl 2-thiouracil in their drinking water for 8 weeks. Age-matched euthyroid rats were used as controls. Lipid peroxidation in the serum was determined by the end-product malondialdehyde (MDA). Oxidative damage to genomic DNA of aortic tissue and serum was investigated by measuring 8-oxo-dG, one of the base modifications produced in DNA by the reaction of reactive oxygen species. Serum lipids measurement was performed. RESULTS: A hypothyroid state was confirmed by levels of serum thyroid hormones, lipidemic profile, clinical examination, pathological findings and cardiovascular hemodynamics parameters. Hypothyroidism was associated with a significant increase in lipid peroxidation. (MDA 1.44 +/-0.93 vs 0.64 +/- 0.53 nmol/l, p < 0 .01). Levels of 8-oxo-dG on the aortic ring, expressing the oxidant damage on genomic DNA and in the serum, were observed to be significantly raised in the hypothyroid group compared to controls (8-oxodG(serum) 29.22 +/- 17.78 vs. 17.56 +/- 4.44 ng/ml, p < 0.01; 8-oxo-dG(aorta)11.58 +/- 2.70 vs. 4.09 +/- 1.27 ng/ml, p < 0. 001). A statistical correlation between measurements of 8-oxo-dG in the aorta and serum was found (correlation coefficient = 0.36, p < 0.05). A hyperlipidemic profile in hypothyroid animals was revealed. CONCLUSION: Vascular oxidative stress seems to play a pivotal role in the evolution of vascular pathology. Hypothyroidism was associated with increased DNA oxidative damage to the aorta. Hypercholesterolemia and an increase in mean arterial pressure associated with hypothyroidism may have a contributive role in the accumulation of damage in nuclear DNA of the vascular wall. 8-Oxo-dG is one of the mutagenic base modifications produced in DNA. Although clinical studies in other tissues have indicated a direct correlation between in vivo 8-oxo-dG formation and pathological processes, its role on the vascular wall needs further investigation.

Hyperthyroidism is associated with increased aortic oxidative DNA damage in a rat model.

BACKGROUND: Hyperthyroidism is associated with increased oxidative stress and oxygen free radical production. Oxygen free radicals are implicated in several signalling pathways leading to vascular pathology. The present study evaluates the extent of aortic oxidative stress in experimental hyperthyroidism. MATERIALS AND METHODS: Chronic hyperthyroidism was induced in 20 male Wistar rats; another 20 animals served as controls. Oxidative damage to lipids and genomic DNA was assessed by measuring serum and aortic wall 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) levels (a mutagenic marker of oxidative DNA damage), as well as serum ceruloplasmin, malondialdehyde (MDA) and lipids. RESULTS: Hyperthyroid animals had significantly higher values of serum ceruloplasmin (11.27+/-1.16 vs. 9.58+/-1.17 mg/dl), MDA (5.34+/-1.32 vs. 0.64+/-0.53 nmol/ml) and 8-oxo-dG (33.91+/-9.63 vs. 17.56+/-4.44 ng/ml) compared with controls (p<0.001 for all associations). Aortic 8-oxo-dG levels were elevated in the thyrotoxic compared with the control group (13.01+/-2.38 vs. 4.09+/-1.27 ng/ml, respectively; p<0.001). 8-Oxo-dG measurements in aortic rings and in serum were positively correlated in the hyperthyroid rats (Pearson's correlation coefficient =0.66; p=0.007). CONCLUSION: Hyperthyroidism is associated with increased oxidative stress in the aortic wall. The animal model we describe has provided some preliminary data regarding the effect of hyperthyroidism on the vascular system. Verification of our results and further exploration of our animal model may help determine the association between oxidative DNA damage with functional changes of the vascular wall, such as endothelial function and vascular nitric oxide signalling.

Topographic anatomy of bronchial arteries in the pig: a corrosion cast study.

The anatomy of porcine bronchial circulation has not been fully described. The purpose of this study was to investigate the extrapulmonary topographic anatomy of bronchial arteries in pig. Ten pigs weighing 15-25 kg were studied. Between one and four bronchial arteries were found in each pig. The bronchoesophageal artery (BEA), tracheobronchial artery (TBA), inferior bronchial artery (IBA) and accessory bronchial artery (ABA) were present in 10/10, 8/10, 6/10 and 2/10 animals, respectively. The trunk of BEA had a diameter of about 3 mm, a length of 1-7 mm, and originated from the anterior and medial aspect of the descending thoracic aorta at the level between the 2nd and 4th thoracic vertebrae (T2-T4) in all animals. The extrapulmonary topographic anatomy of bronchial arteries in pigs exhibits similarities to that of humans. BEA is the main blood supplier of the porcine tracheobronchial tree with a relatively constant location of origin and a sufficient size for anastomosis. These characteristics render BEA the ideal vessel for bronchial revascularization in pigs.

In vivo effect of the lipido-sterolic extract of Serenoa repens (Permixon) on mast cell accumulation and glandular epithelium trophism in the rat prostate.

The Serenoa repens lipido-sterolic extract (SRLSE, Permixon, Pierre Fabre Medicament, Castres, France) is used to treat benign prostate hyperplasia. We studied the in vivo effect of SRLSE on mast cell accumulation and the histological characteristics of the rat ventral prostate. Adult Wistar rats received either tocopherol or SRLSE (50 and 100 mg/kg body weight, respectively) every second day for 90 days. Histological features were studied in hematoxylin-eosin stained tissue sections while mean mast cell numbers were determined in Giemsa-stained sections. The central region of the ventral prostate in treated animals showed significant changes with acinar epithelium becoming flat or low cuboidal. In the same region, mean mast cell number per optical field in the control, low-dose and high-dose groups were, respectively, 4.7+/-0.7, 3.4+/-1.0 and 2.4+/-0.6, showing a dose-dependent, statistically significant decrease. Administering SRLSE significantly reduces mast cell accumulation and provokes epithelium atrophy within the central area of the rat ventral prostate. These phenomena may participate in the clinical activity of the drug.