Heparin attenuates low-dose streptozotocin-induced immune diabetes in mice and inhibits the beta-cell binding of T-splenocytes in vitro

Heparin modulation on hepatic nitric oxide synthase in experimental steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is considered to be a hepatic manifestation of metabolic syndrome, and has been etiologically associated with insulin resistance (IR). The histopathology of NAFLD ranges between simple steatosis and nonalcoholic steatohepatitis (NASH), with or without fibrosis. The aim of the present study was to examine the effect of heparin on steatohepatitis and hepatic-induced nitric oxide synthase (iNOS) expression in mice. Male mice were divided into four groups, which included the normal basal diet (control), high fat (HF) diet, HF diet + heparin (treatment group) and heparin control groups. After eight weeks from the initiation of the experiment, blood was collected and livers were harvested for biochemical analysis and histological studies. Serum levels of aspartate aminotransferase, alanine aminotransferase, hepatic triglyceride (TG) and hydroxyproline, as well as the IR, superoxide anion generation and mRNA expression of the hepatic iNOS enzyme were evaluated. Liver specimens were processed for histopathological and immunohistopathological evaluation. Heparin administration decreased the levels of the liver enzymes, IR, superoxide generation, hepatic TG, hydroxyproline and iNOS expression when compared with the HF diet group. These changes were associated with an improvement in inflammation and fibrosis observed via histopathological examination. Therefore, heparin treatment attenuates hepatic injury in steatohepatitis.

Examination of the immunosuppressive effect of delta9-tetrahydrocannabinol in streptozotocin-induced autoimmune diabetes

delta9-Tetrahydrocannabinol (delta9-THC) is capable of modulating a variety of immune responses, but has not been evaluated in models of immune-based diabetes. The objectives of the present study were: (a) to investigate the effect of delta9-THC in an established model of multiple low dose streptozotocin (MLDSTZ)-induced autoimmune diabetes; and (b) to determine the contribution of the immune response in the MLDSTZ model. CD-1 mice were treated with 40 mg/kg STZ for 5 days in the presence or absence of delta9-THC treatment. delta9-THC administered orally in corn oil at 150 mg/kg for 11 days attenuated, in a transient manner, the MLDSTZ-induced elevation in serum glucose and loss of pancreatic insulin. MLDSTZ-induced insulitis and increases in IFN-gamma, TNFalpha and IL-12 mRNA expression were all reduced on Day 11 by co-administration of delta9-THC. In separate studies, six doses of delta9-THC, given after completion of STZ treatment, was found equally effective in attenuating mice from MLDSTZ-induced diabetes. Studies performed using B6C3F1 mice showed moderate hyperglycemia and a significant reduction in pancreatic insulin by MLDSTZ in the absence of insulitis. In addition, MLDSTZ produced a less pronounced hyperglycemia compared to CD-1 mice that was not attenuated by delta9-THC. These results suggest that MLDSTZ can initiate direct beta-cell damage, thereby augmenting the destruction of beta-cells by the immune system. Moreover, these results indicate that delta9-THC is capable of attenuating the severity of the autoimmune response in this experimental model of autoimmune diabetes.

The effect of a heparin analogue, ITF-5005, on diabetes incidence and insulitis in the non-obese diabetic mouse

It has been suggested that heparin and its analogues may have a suppressive effect on the immune response by interfering with T-lymphocyte heparinase activity, thus altering the ability of T-lymphocytes to penetrate the extracellular matrix and migrate to target tissues. We have investigated whether a heparin analogue (ITF-5005) can alter lymphocytic infiltration of the endocrine pancreas (insulitis) and/or diabetes incidence in the non-obese diabetic (NOD) mouse. Sixty-four NOD mice were divided at weaning and injected subcutaneously five times per week with either 18, 36 or 72 micrograms/kg body weight of ITF-5005 or saline as a control. At 12 weeks of age, the animals were culled and their pancreata sectioned, stained and assessed 'blind' for insulitis and insulin containing cells. Insulitis was similar in all groups as was the proportion of insulin-containing cells. To determine the effect on diabetes incidence, two groups of mice were injected with either saline or 140 micrograms/kg body weight of ITF-5005 from weaning until 30 weeks of age. No difference was found in overall diabetes incidence; however, disease onset was significantly accelerated in the treated group. We conclude that ITF-5005, at the doses employed, has no effect on insulitis or the proportion of treated group. We conclude that ITF-5005, at the doses employed, has no effect on insulitis or the proportion of insulin-containing cells found in the pancreas, but that it can accelerate the course of diabetes in the NOD mouse.

Altering the course of proliferative nephritides: the challenge of the 1990s

There is considerable evidence based on experimental pathology that heparin/heparinoids will benefit the course of the various forms of human proliferative nephritis. An alternative to heparin may be pentosan polysulphate. Another possibility is the infusion of prostaglandin E1 because of its anti-inflammatory and potentially antiproliferative actions. Both these approaches mimic natural pathophysiological control mechanisms.