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The effects of lipopolysaccharide (LPS) and desArg9Bradykinin (DBK) on the release of nitric oxide (NO) from macrophages of mice 8, 12 and 18 days after having been treated with low doses of streptozotocin (STZ; 5 × 45 mg/kg) were studied. The results showed that LPS stimulated the release of NO from macrophages of untreated animals by 50% whereas the bradykinin B(1) agonist desArg9Bradykinin (DBK) increased the level of NO by 20%. This increased NO production was totally abolished by incubating the cells with R-954, a selective bradykinin B(1) antagonist. The release of NO from macrophages of STZ-treated mice incubated in the presence of LPS was more marked and reached approximately 220, 300 and 270% respectively from cells collected 8, 12 and 18 days after the STZ treatment. These significant increases were completely blocked by R-954 and were even below control values. Similarly the results showed that DBK stimulated by 50-75% the release of NO from macrophages of STZ-treated mice. The most marked stimulation was noted when the cells were collected 18 days after the treatment of the animals with STZ. Again in this set of experiments the B(1) antagonist completely blocked the release of NO which went even below control values. The results clearly suggest the upregulation of bradykinin B(1) receptors in mouse macrophages in the early phase of STZ-induced diabetes, an event that could even precede the onset of the diabetic hyperglycemia.

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Islet inflammation or insulitis is followed by selective destruction of the insulin secreting B-cell. Animal models of insulin-dependent diabetes mellitus (IDDM) have been used to characterize more fully insulitis, and our results with C57/BL/Ks mdb with low doses of streptozotocin (STZ) confirmed the disease. B1 receptor antagonist [Leu8]des-Arg9-BK has shown a significant effect on diabetic glycemia and renal control parameters. Compared to insulin, the drug was effective to prevent the insulitis and the renal damage. On the other hand, B2 receptor antagonist (HOE 140) and ACE-I (captopril) were only able to control the urinary diabetic proteinuria.

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The purpose of the present work was to evaluate the kallikrein-kinin system and effects of hypothermia during renal ischemia and reperfusion. Male C57BL/KSJmdb mice were subjected to 20 or 60 min ischemia for different periods of reperfusion. Our results demonstrate that short periods of ischemia followed by reperfusion did not cause significant alterations in kallikrein activity, Evans Blue (EB) extravasation, prokallikreins, myeloperoxidase activity or plasma creatinine concentration. Edema was evident at 1 h reperfusion in the treated mice, but returned to basal values after 24 h reperfusion. Kallikrein activities and EB extravasation showed a significant increase in 60 min ischemic mice. Myeloperoxidase activity in the kidney of the mice confirmed net infiltration in the group with 60 min ischemia and 24 h reperfusion. The generation of kinins and activation of matrix degrading enzymes by tissue kallikrein, liberated from both renal and infiltrated leukocytes, could be responsible at least in part for the damage observed in the kidney of mice subject to 60 min ischemia and reperfusion. The hypothermia significantly reduced the inflammatory process in the 60 min ischemic mice, and did prevent an increase in vascular permeability. Nevertheless, the tissue edema was not shown to change between normothermic and hypothermic ischemic mice.

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Diabetic nephropathy is associated with increased urinary albumin and reduce kallikrein excretion. Increased activity of the renal kallikrein-kinin system has been suggested as one of the possible mechanisms underlying diabetic hyperfiltration. The present study shown that the Kallikrein-kinin system is progressively increased in the diabetic-pregnant rats at 7, 14, 21 days; 48 and 7 days after pregnancy (P < 0.05 vs Control). However, this increase during diabetic pregnancy did not reached the levels of control pregnancy. On the other hand albumin excretion shown a significant and progressive renal damage in the diabetic state. These findings suggest that the diabetic pregnancy could impair the renal hemodynamic, but, on the other side could modulate the vasodilator system at pregnancy in the attempt to protect the fetus.

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Diabetic nephropathy is associated with increased urinary albumin and reduce kallikrein excretion. Increased activity of the renal kallikrein-kinin system has been suggested as one of the possible mechanisms underlying diabetic hyperfiltration. The present study shown that the Kallikrein-kinin system is progressively increased in the diabetic-pregnant rats at 7, 14, 21 days; 48 and 7 days after pregnancy (P < 0.05 vs Control). However, this increase during diabetic pregnancy did not reached the levels of control pregnancy. On the other hand albumin excretion shown a significant and progressive renal damage in the diabetic state. These findings suggest that the diabetic pregnancy could impair the renal hemodynamic, but, on the other side could modulate the vasodilator system at pregnancy in the attempt to protect the fetus.

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Nitric oxide synthase activity was measured in Langerhans islets isolated from control and streptozotocin diabetic rats. The activity of the enzyme was linear up to 150 micrograms of protein from control rats and was optimal at 0.1 microM calcium, when it was measured after 45 min of incubation at 37 degrees C in the presence of 200 microM arginine. Specific activity of the enzyme was 25 x 10(-4) nmol [3H]citrulline 45 min-1 mg protein-1. Streptozotocin diabetic rats exhibited less enzyme activity both in total pancreas homogenate and in isolated Langerhans islets when compared to control animals. Nitric oxide synthase activity measured in control and diabetic rats 15 days after the last streptozotocin injection in the second group of animals corresponded only to a constitutive enzyme since it was not inhibited by aminoguanidine in any of the mentioned groups. Hyperglycemia in diabetic rats may be the consequence of impaired insulin release caused at least in part by reduced positive modulation mediated by constitutive nitric oxide synthase activity, which was dramatically reduced in islets severely damaged after streptozotocin treatment.

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Nitric oxide synthase activity was measured in Langerhans islets isolated from control and streptozotocin diabetic rats. The activity of the enzyme was linear up to 150 mug of protein from control rats and was optimal at 0.1 muM calcium, when it was measured after 45 min of incubation at 37ºC in the presence of 200 muM arginine. Specific activity of the enzyme was 25 x 10(-4) nmol [3H] citrulline 45 min(-1) mg protein(-1). Streptozotocin diabetic rats exhibited less enzyme activity both in total pancreas homogenate and in isolated Langerhans islets when compared to control animals. Nitric oxide synthase activity measured in control and diabetic rats 15 days after the last streptozotocin injection in the second group of animals corresponded only to a constitutive enzyme since it was not inhibited by aminoguanidine in any of the mentioned groups. Hyperglycemia in diabetic rats may be the consequence of impaired insulin release caused at least in part by reduced positive modulation mediated by constitutive nitric oxide synthase activity, which was dramatically reduced in islets severely damaged after streptozotocin treatment.

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Sub-diabetogenic doses of streptozotocin (STZ) produce insulitis, beta cell destruction and diabetes in mice. Since kinin have been proposed as an inflammatory mediator in several diseases, we decided to evaluate the role of the kallikrein-kinin system in the evolution of insulitis. Male C 57 BL/KsJ mdb mice were injected with STZ (40 mg/kg) for 5 consecutive d. Aprotinin (4000 KIU/d) was injected simultaneously with STZ during 10 d. Plasma and urine samples collected on day 15 were assayed for glucose concentration and proteins, nitrites and kallikrein. Diabetic mice showed hyperglycemia and increased diuresis, marked proteinuria, nitrites and kallikrein. Administration of aprotinin, a potent tissue kallikrein inhibitor, to STZ mice, reduced the hyperglycemia and the altered renal function of the diabetic mice to level no different from normal mice. The present studies are consistent with the hypothesis that the over-production of tissue kallikrein in insulitis could be controlled by the effect of aprotinin.

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To investigate in mice the mechanisms underlying renal functions in a type I diabetes model, we have suppressed B2 kinin receptors local activities by their specific antagonist D-Arg [Hyp3-Thi5-D-Tic7-Oic8]BK (HOE 140). Mice made diabetic with low consecutive doses of streptozotocin (STZ) (45 mg/k BW during 5 days) were injected with HOE 140 (15 micrograms/twice a day) for 15 days. This drug did not modify glycemia of STZ treated animals but a significantly reduction of urinary proteins, nitrites and kallikrein was observed. These results indicate that kinin B2-receptors activation is implicated in the alterations of renal function in this model of type I diabetes in mice.

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1. Diabetes mellitus type I was induced in 3-month old male C57 BL/KS-mdb mice (N = 24) by ip injection of streptozotocin (STZ, 45 mg/kg body weight) for 5 days. 2. To determine the possible protective effects of nitric oxide inhibition against hyperglycemia, the STZ-diabetic rats received two doses of NG-nitro-L-arginine- methyl ester (L-NAME) (10 mg/kg body weight and 10 mg/mouse) dissolved in PBS for 45 consecutive days. Another group of STZ-treated rats was similarly treated with L-arginine (5 mg/mouse). 3. Blood glucose levels were 118 +/- 37 mg/dl after 8 days of L-NAME administration (10 mg/kg body weight, N = 12) and 186 +/- 22 mg/dl (N = 12) after 5 days of L-NAME administration at the 5 mg/mouse dose. Treatment with L-arginine (5 mg/mouse, N = 12) caused a significant increase in blood glucose level to 151 +/- 17.5 mg/dl, showing the relevance of nitric oxide formation in this type of diabetes. 4. In STZ-diabetic mice treated with L-NAME (N = 12), diuresis was reduced by approximately 58% compared to STZ animals, whereas in L-arginine-treated animals (N = 12) diuresis returned to STZ levels. Urinary protein excretion, which was significantly affected by STZ (123% compared to control) was significantly reduced by 66% after treatment with L-NAME for 45 days, whereas treatment with L-arginine caused a return to STZ values. 5. Urinary kallikrein excretion, which was reduced by 80% in STZ mice compared to control, returned to control levels after L-NAME treatment. 6. The present results suggest a relationship between nitric oxide levels and the reduction of diabetic state and improved renal function by L-NAME.

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1. Diabetes mellitus type 1 was induced in 3-month old maleC57 BL/KS-mdb mice (N = 24)) by ip injection of streptozotocin (STZ, 45 mg/Kg body weight) for 5 days. 2. To determine the possible protective effects of nitric oxide inhibition against hyperglycemia, the STZ-diabetic rats received two doses of Ng-nitro-l-arginine-methyl ester (L-NAME) (10 mg/Kg body weight and 10 mg/mouse) dissolved in PBS for 45 consecutive days. Another group of STZ-treated rats was similarly treated with L-arginine (5 mg/mouse). 3. Blood glucose levels were 118 ñ 37 mg/dl after 8 days of L-NAME administration (10 mg/Kg body weight, N = 12) and 186 ñ 22 mg/dl (N = 12) after 5 days of L-NAME administration at the 5 mg/mouse dose. Treatment with L-arginine (5-mg/mouse, N = 12) caused a significant increase in blood glucose level to 151 ñ 17,5 mg/dl, showing the relevance of nitric oxide formation in this type of diabetes. 4. In STZ-diabetic mice treated with L-NAME (N = 12), diuresis was reduced by approximately 58 per cents compared to STZ animals, whereas in L-arginine-treated animals (N = 12) diuresis returned to STZ levels. Urinary protein excretion, which, was significantly affected by STZ (123 per cents compared to control) was significanty reduced by 66 per cents after treatment with L-NAME for 45 days, whereas treatment with-L-arginine caused a return to STZ values. 5. Urinary kallikrein excretion, which was reduced by 80 per cents in STZ mice compared to control, returned to control levels after L-NAME treatment. 6. The present results suggest a relationship between nitric oxide levels and the reduction of diabetic state improved renal function by L-name

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The kallikrein-kinin system was studied in 9 normals, healthy subjects (6 men, 3 women, age range 1 to 14 years) and 15 diabetic patients (9 men, 6 women age range 2 to 14 years) with an evolution of the disease between 1 to 14 years. Diabetic patients with low microalbuminuria (6.62 +/- 0.97 mg/24 h) show increased total and pre-kallikrein respect to control (3 and 2 fold respectively). On the other hand patients with high microalbuminuria (44.7 +/- 13.2 mg/24 h) show a total and pre-kallikrein of more than 4 and 8 fold increased respectively, compare with the control. According with these results we can concluded: 1) The total kallikrein and pre-kallikrein is increased in the diabetic state. 2) When microalbuminuria is high, the total and pre-kallikrein correlates with those increasing. 3) These changes could modified the renal hemodynamic in diabetes.

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The cribriform degeneration (cri) mutant mouse was widely studied in regard to the electrolyte and kallikrein metabolism because of its potentiality as a cystic fibrosis (CF) genetic animal model. In this paper the activity of the kallikrein-kinin system, and the kininase activity and glycoproteins concentration in colon and pulmonary lavage fluid (PLF) in homozygous mutant (cri/cri) and control sibling mice are described. The mutant mice showed a diminished kininogenase and kininase activity and glycoproteins concentrations in both studied organs. It is concluded that a kallikrein-kinin system alteration could be responsible of the cri/cri electrolyte defect.

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Kallikrein content in lavage of the respiratory tract was determined by a specific RIA. The results show an immunological identity of the lung kallikrein with the standard rat urinary kallikrein. The levels of immunoreactive lung fluid kallikrein were significantly lower in rats injected with reserpine.

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The submandibular gland of cri/cri and control mice were compared for their activity of glandular kallikrein like esteroprotease and kininase. Esteroprotease activity is significantly reduced in cri/cri mice with respect to control, with an increased kininase activity in cri/cri mice. Since previous work showed an electrolyte abnormality in the salivary glands of this mutant mouse (1) a possible relationship between this alteration with the low activity of cellular esteroprotease and the high kininase activity is suggested.

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The isolated tail artery when exposed to 0.14-2.80 microM tityustoxin (a purified peptide from the venom of the scorpion Tityus serrulatus) underwent a transient contraction which was followed by a long lasting period of unresponsiveness to further additions of the toxin. Reserpine pretreatment, the addition of phentolamine, tetrodotoxin, verapamil or lowering the sodium concentration abolished the responses to the toxin. Cocaine potentiated it. Tityustoxin caused a slight leftward shift of the dose-response curves to adrenaline and norepinephrine and a large potentiation of the frequency-response curves to electrical stimulation. The latter effect was greater within the lower range of frequencies assayed, which coincide with those of the physiological discharge of sympathetic nerves. These data indicate that in the tail artery the tityustoxin acts indirectly on the smooth muscle through the release of endogenous catecholamines. Most likely, changes of the properties of the sodium channels and calcium influx are involved in this effect at the nerve endings. The potentiation of the frequency-response curves suggests that the arterial hypertension produced by the scorpion sting may result mainly from an abnormally elevated overflow of sympathetic transmitters.

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The isolated tail artery when exposed to 0.14-2.80 microM tityustoxin (a purified peptide from the venom of the scorpion Tityus serrulatus) underwent a transient contraction which was followed by a long lasting period of unresponsiveness to further additions of the toxin. Reserpine pretreatment, the addition of phentolamine, tetrodotoxin, verapamil or lowering the sodium concentration abolished the responses to the toxin. Cocaine potentiated it. Tityustoxin caused a slight leftward shift of the dose-response curves to adrenaline and norepinephrine and a large potentiation of the frequency-response curves to electrical stimulation. The latter effect was greater within the lower range of frequencies assayed, which coincide with those of the physiological discharge of sympathetic nerves. These data indicate that in the tail artery the tityustoxin acts indirectly on the smooth muscle through the release of endogenous catecholamines. Most likely, changes of the properties of the sodium channels and calcium influx are involved in this effect at the nerve endings. The potentiation of the frequency-response curves suggests that the arterial hypertension produced by the scorpion sting may result mainly from an abnormally elevated overflow of sympathetic transmitters.