Animals ; Brain ; metabolism ; Brain Injuries ; metabolism ; Enzyme Inhibitors ; pharmacology ; Guanidines ; pharmacology ; Neuroprotective Agents ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; Rats

Nitric oxide (NO) has been considered as an important mediator in inflammatory phases and in loss of cartilage. In inflammatory arthritis, NO levels are correlated with disease activity and articular cartilage is able to produce large amounts of NO with the appropriate inducing factor such as cytokines. The old animals are shown to have a greater sensitivity to NO than young animals. This study evaluated the basal production of NO in normal and OA-affected chondroyctes from young and old patients and compared the levels of NO formation in response to IL-1beta. The results showed that the basal levels were 7-fold higher in old chondrocytes than those of young cells. However, the IL-1beta induced NO production was seen to decrease with age. Aminoguianidine (AG), a competitive inhibitor of iNOS, inhibited NO formation completely in both chondrocytes from young and old individuals. However, at the same concentration of AG it caused partial inhibition of NO and iNOS formation in chondrocytes from OA-affected individuals. In addition, although the IL-1beta induced NO production was much lesser than that of young chondrocytes, the inhibition of collagen production by IL-1beta was prominent in old chondrocytes and OA-affected chondrocytes. These results suggest that age-related differences in the regulation of NO production and collagen production, which may affect the ageing cells and osteoarthritic changes in some way.
Aging/*physiology ; Cartilage, Articular/*physiopathology ; Cells, Cultured ; Chondrocytes/*metabolism ; Collagen Type II/metabolism ; Enzyme Inhibitors/pharmacology ; Guanidines/pharmacology ; Human ; Interleukin-1/pharmacology ; Nitric Oxide/*biosynthesis ; Osteoarthritis/*metabolism

Nitric oxide (NO) has been considered as an important mediator in inflammatory phases and in loss of cartilage. In inflammatory arthritis, NO levels are correlated with disease activity and articular cartilage is able to produce large amounts of NO with the appropriate inducing factor such as cytokines. The old animals are shown to have a greater sensitivity to NO than young animals. This study evaluated the basal production of NO in normal and OA-affected chondroyctes from young and old patients and compared the levels of NO formation in response to IL-1beta. The results showed that the basal levels were 7-fold higher in old chondrocytes than those of young cells. However, the IL-1beta induced NO production was seen to decrease with age. Aminoguianidine (AG), a competitive inhibitor of iNOS, inhibited NO formation completely in both chondrocytes from young and old individuals. However, at the same concentration of AG it caused partial inhibition of NO and iNOS formation in chondrocytes from OA-affected individuals. In addition, although the IL-1beta induced NO production was much lesser than that of young chondrocytes, the inhibition of collagen production by IL-1beta was prominent in old chondrocytes and OA-affected chondrocytes. These results suggest that age-related differences in the regulation of NO production and collagen production, which may affect the ageing cells and osteoarthritic changes in some way.
Aging/*physiology ; Cartilage, Articular/*physiopathology ; Cells, Cultured ; Chondrocytes/*metabolism ; Collagen Type II/metabolism ; Enzyme Inhibitors/pharmacology ; Guanidines/pharmacology ; Human ; Interleukin-1/pharmacology ; Nitric Oxide/*biosynthesis ; Osteoarthritis/*metabolism

OBJECTIVETo investigate the protective effects of Cariporide on immature rabbit heart, and to search for the protective mechanism of the Na(+)/H(+) exchange inhibitor on immature rabbit hearts.

METHODSNew Zealand immature rabbits were randomly divided into two groups (n = 12 in each group). The isolated rabbit heart model was involved in this study. The hearts were submitted to 60 minutes of normothermic ischemia with cardioplegia per 20 minutes of reperfusion. Group I received St. Thomas No2 as cardioprotective solution. Group II received St. Thomas No2 with addition of cariporide (10 micro mol/L). The left ventricular function was recorded, including left ventricular systolic pressure (LVSP), left ventricular dystolic pressure (LVDP), coronary artery flow (CAF), mean aortic pressure (MAP), aortic flow (AF) and dp/dt max. The levels of creatine phosphokinase (CK), lactic dehydrogenase (LDH) of coronary sinus venous solution were measured. The ventricular cardiomyocytes isolated from other 6 immature rabbit hearts were subdivided into 3 groups of each heart, which were attained by means of collagenase-perfusion. All cells were incubated with calcium fluoresence indicator Fluo-3/AM, and then the intracellular free calcium was measured under the laser scanning con-focal microscopy. The baseline was measured after isolation without anoxic/re-oxygenation. The control group received anoxic conditions for 60 minutes and re-oxygenation for 30 minutes, then was measured. The experiment group received the same conditions as control group with addition of Cariporide (1 micromol/L).

RESULTSAfter ischaemia/reperfusion, the percentage of recovery of myocardial function in group II was much better than group I; the LVDP, LVSP, MAP, AF, CAF and dp/dt max showed markedly better recovery in group II. The release of CK, LDH was significantly increased in Group I. After anoxic/re-oxygenation, the intracellular free calcium of isolated immature rabbit ventricular myocytes in control group increased significantly than baseline (P < 0.01); there were no significant difference of immature myocardial [Ca(2+)]i between experiment group and baseline (P > 0.05); and the experiment group myocardial [Ca(2+)]i reduced significantly than control (P < 0.01).

CONCLUSIONSCariporide demonstrates significant cardio-protective effects for immature myocardium ischemia/reperfusion, and the protective mechanism may be due to the inhibition of the intracellular free calcium overload.

Animals ; Arrhythmias, Cardiac ; etiology ; Calcium ; metabolism ; Female ; Guanidines ; pharmacology ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Rabbits ; Sodium ; metabolism ; Sodium-Hydrogen Exchangers ; antagonists & inhibitors ; Sulfones ; pharmacology

Aging ; physiology ; Animals ; Arteries ; physiopathology ; Arteriosclerosis ; physiopathology ; Blood Pressure ; drug effects ; Diabetes Mellitus ; physiopathology ; Glycation End Products, Advanced ; antagonists & inhibitors ; metabolism ; physiology ; Guanidines ; pharmacology ; Humans ; Thiazoles ; pharmacology

OBJECTIVETo investigate the effect of Wenjingtong Composita (WJTC) on blood glucose and advanced glycosylation end products (AGEs) in sciatic nerve of streptozotocin (STZ)-induced diabetic rats.

METHODSSTZ-induced diabetic rats were randomized to WJTC prevention group and WJTC treatment group. The levels of blood glucose and AGEs in sciatic nerve of the animals were checked after 12 weeks treatment and compared with that of aminoguanidine (AG) treatment group.

RESULTSBlood glucose level in the WJTC prevention and treatment group, and AGEs in sciatic nerve of the WJTC prevention group and the AG group were lower than those of the non-treated group (P < 0.01). Blood glucose level in the AG group was higher than that in the WJTC prevention group (P < 0.05), but was not significantly different from that in the non-treated group (P > 0.05).

CONCLUSIONWJTC might prevent diabetic peripheral neuropathy by decreasing blood glucose and inhibiting AGEs formation in sciatic nerve in STZ-induced diabetic rats.

Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; metabolism ; Diabetic Neuropathies ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Glycosylation ; drug effects ; Guanidines ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Wistar ; Sciatic Nerve ; metabolism ; Sciatic Neuropathy ; metabolism

OBJECTIVETo investigate the role of advanced glycation end products (AGEs) and their receptors (RAGE) in the pathogenesis of diabetic mellitus erectile dysfunction (DMED) and the effects of AGEs and RAGE on the activity of endothelin-1 (ET-1) in rat cavernosum.

METHODSForty male Sprague-Dawley rats were taken at random to construct 2 groups of diabetes mellitus (DM) models of equal number, one given free access to water and the other administered aminoguanidine hydrochloride (DM + AG) in water at the dose of 1 g/L. Another 20 male SD rats were equally divided into a normal control and an AG control group. After 8 weeks, the cavernosum tissues were harvested from all groups of rats, part of the isolated penile tissues homogenated to detect the content of AGE-peptide (AGE-P) and the activity of ET-1, and the AGEs and RAGE in the rest of the penile tissues analyzed by immunohisto- chemical assay.

RESULTSCompared with the normal controls, the expressions of AGEs and RAGE, the content of AGE-P and the activity of ET-1 in the cavernosum tissues were significantly high in the DM group (P < 0.05), while the administration of AG to the DM rats reversed the above results. No significant difference was observed between the normal control and AG control groups in any of the data (P > 0.05).

CONCLUSIONIn DM conditions, the joint effect of AGEs and RAGE may elevate the activity of ET-1 in rat cavernosum and thus promote the development of DMED.

Animals ; Diabetes Mellitus, Experimental ; metabolism ; physiopathology ; prevention & control ; Endothelin-1 ; metabolism ; Enzyme Inhibitors ; administration & dosage ; Glycation End Products, Advanced ; antagonists & inhibitors ; metabolism ; Guanidines ; administration & dosage ; Male ; Penis ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Cell Surface ; metabolism

OBJECTIVETo explore the effects of intrathecal injection of neuronal nitric oxide synthase (nNOS) inhibitors 7-Nitroindazole (7-Ni) and inducible nitric oxide synthase(iNOS) inhibitors aminoguanidine (AG) on the behavioral changes of morphine-induced dependent and withdrawal rats; the expression of Fos, nNOS and iNOS in spinal cord.

METHODSTo set up morphine dependence model, rats were subcutaneously injected with morphine (twice a day, for 5 d). The dose of morphine was 10 mg/kg in the first day and was increased by 10 mg/ kg every day. On day 6, 4 h after the injection of morphine (50 mg/kg), morphine withdrawal syndrome was precipitated by an injection of naloxone (4 mg/kg ip). 7-Ni, an nNOS inhibitor or iNOS inhibitors AG were intrathecally injected 30 min before the administration of naloxone respectively. The scores of morphine withdrawal symptom and morphine withdrawal-induced allodynia were observed. One hour after naloxone-precipitated withdrawal, Fos protein expression was assessed by immunohistochemical analysis and Western blot was used to detect the expression of nNOS and iNOS in the rat spinal cord.

RESULTSIntrathecal administration of nNOS inhibitor 7-Ni and iNOS inhibitors AG decreased the scores of morphine withdrawal, attenuated morphine withdrawal-induced allodynia and also inhibited the increase of Fos protein expression in the spinal cord of morphine withdrawal rats. nNOS and iNOS positive neurons in dorsal horn in nNOS group and iNOS group were significantly lower than that in withdrawal group. Compared with withdrawal group, level of nNOS and iNOS protein in spinal cord in nNOS group and iNOS group were significantly lower.

CONCLUSIONIt is suggested that nNOS and iNOS in the spinal cord may contribute to naloxone-precipitated withdrawal in rats and may play different roles in the above-mentioned effect.

Animals ; Guanidines ; pharmacology ; Indazoles ; pharmacology ; Male ; Morphine Dependence ; metabolism ; Naloxone ; pharmacology ; Nitric Oxide Synthase Type I ; antagonists & inhibitors ; metabolism ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; metabolism ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; drug effects ; metabolism ; Substance Withdrawal Syndrome ; metabolism

It has been demonstrated that inhibitors of advanced glycation end products (AGE), such as aminoguanidine, can suppress peritoneal AGE in rats on peritoneal dialysis (PD). However, it is unknown whether late administration of a putative crosslink breaker, alagebrium, could reverse peritoneal AGE. We therefore compared alagebrium with aminoguanidine in their ability to reverse peritoneal AGE in rats on PD. Male Sprague-Dawley rats were randomly divided into 3 groups: group I dialyzed with 4.25% glucose solution for all exchanges; group II dialyzed with 4.25% glucose solution containing aminoguanidine, and group III dialyzed with 4.25% glucose solution containing alagebrium for last 8 weeks of 12-week dialysis period. Dialysis exchanges were performed 2 times a day for 12 weeks. Immunohistochemistry was performed using a monoclonal anti-AGE antibody. One-hour PET was performed for comparison of transport characteristics. The immunolabelling of AGE in peritoneal membrane was markedly decreased in the alagebrium group. Consistent with this, the alagebrium group exhibited significantly higher D/Do glucose and lower D/P urea, suggesting low peritoneal membrane transport. But there were no significant differences between the control and the aminoguanidine group. These results suggest that the alagebrium may be the optimal therapeutic approach, compared with treatment with inhibitors of AGE formation, in rats on PD.
Animals ; Biological Transport ; Body Weight ; Cell Membrane/metabolism ; Glycosylation End Products, Advanced/*metabolism ; Guanidines/metabolism ; Immunohistochemistry/methods ; Male ; Peritoneal Dialysis/*methods ; Peritoneum/metabolism/*pathology ; *Permeability ; Rats ; Rats, Sprague-Dawley

AIMTo investigate the effects of L-arginine and nitric oxide synthase (NOS) inhibitor Aminoguanidine (AG) on endotoxin induced lung injury in rats.

METHODSForty eight healthy male SD rats weighing (300 +/- 20) g were used. The animals were anesthetized with 20% urethane 1 g x kg(-1). Common carotid artery (CAA) and common carotid vein (CAV) were exposed through a median incision in the neck. Mean arterial pressure (MAP) was measured through a pressure transducer connected with intubation of CAA. The animals were randomly divided into six groups: group 1: control: group 2: LPS (5 mg x kg(-1) intravenous injection, i.v.); group 3: AG (50 mg x kg(-1) intraperitoneal injection, IP); group 4: high dose L-arginine (500 mg x kg(-1), IP); group 5: low dose L-arginine (250 mg x kg(-1) IP). Group 6: L-arginine + AG (250 mg x kg(-1), 50 mg x kg(-1), IP). Group 1: The animals were killed 6 h after 0.9% saline solution was given. Group 2: 0.9% saline solution was given 3 h after LPS i.v. and the animals were killed 3 h after medication. Group 3, 4, 5 and 6: AG, L-arginine and L-arginine+ AG were given 3 h after LPS i.v. respectively and the animals were killed 3 h after medication respectively. The pulmonary was removed immediately. The pulmonary coefficient and water content in pulmonary tissue were calculated (%). The NO content in plasma, MDA content and NOS, SOD activity in the pulmonary tissue were measured.

RESULTSL-arginine, AG and L-arginine + AG significantly decreased pulmonary coefficient and water content in pulmonary tissue and ameliorated endotoxin induced lung injury. AG and L-arginine + AG significantly decreased NO content in plasma, decreased MDA content and inhibited NOS activity and enhanced SOD activity in the pulmonary tissue.

CONCLUSIONIt may be concluded that L-arginine, AG and L-arginine + AG have beneficial effects on lung injury induced by LPS.

Animals ; Arginine ; administration & dosage ; therapeutic use ; Endotoxins ; adverse effects ; Guanidines ; administration & dosage ; therapeutic use ; Lung Injury ; chemically induced ; drug therapy ; Male ; Malondialdehyde ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism