thiourea and Hyperglycemia

Some new benzenesulfonylthiourea derivatives substituted with phthalazones (2a-q) were synthesized by refluxing the appropriate 4-aryl-1-oxophthalazin-2(1H)yl benzenesulfonamides with isothiocyanate in dry acetone over anhydrous K₂CO₃. All the synthesized compounds were characterized on the basis of IR, (1)H NMR, MS data and elemental analysis. These synthesized compounds (2a-q) at the dose of 20 mg/kg were tested for antihyperglycemic activity in the glucose-fed hyperglycemic normal rat model and among these compounds 2f and 2m showed modest antihyperglycemic activity.

Topics: Animals; Benzenesulfonates; Blood Glucose; Drug Design; Female; Glucose; Hyperglycemia; Hypoglycemic Agents; Isothiocyanates; Male; Phthalazines; Rats; Rats, Wistar; Structure-Activity Relationship; Thiourea

Hyperglycemia is the major cause of diabetic angiopathy. The aim of our study was to evaluate the impact of KB-R7943, an inhibitor of Na+/Ca2+ exchanger (NCX) on cell growth and function of human "diabetic" endothelial cells (EC). Intercellular adhesion molecule-1 (ICAM-1) expression and NCX activity were determined after EC were exposed to high glucose in the absence and presence of KB-R7943. Coincubation of EC with high glucose for 24 h resulted in a significant increase of monocyte-endothelial cell adhesion and the expression of ICAM-1. These effects were abolished by KB-R7943 and KB-R7943 significantly decreased the activation of NCX induced by high glucose. These findings suggested that KB-R7943 may play a role in inhibiting expression of adhesion molecules by inhibiting the reverse activation of NCX.

Topics: Blood Glucose; Cell Adhesion; Cells, Cultured; Diabetic Angiopathies; Endothelium, Vascular; Humans; Hyperglycemia; Intercellular Adhesion Molecule-1; Monocytes; Sodium-Calcium Exchanger; Thiourea

Hyperglycemia is known to worsen the outcome of transient global or forebrain ischemia. The aggravating effect is believed to be mediated by the additional formation of lactate- and of H+. Recent evidence suggests that reactive oxygen species contribute to the damage after brain ischemia. Since acidosis accelerates free radical damage in vitro, we decided to explore if ischemic damage in hyperglycemic subjects is ameliorated by dimethylthiourea (DMTU), an established free radical scavenger. In one series of hyperglycemic rats, we studied whether preischemic administration of DMTU alters the clinical outcome, notably the incidence and frequency of seizures. In two different series, the effect of DMTU on tissue damage was assessed by light microscopy after 15 h of recovery. Longer periods could not be studied since seizures developed. In the first of these series the animals were anesthetized with isoflurane, and in the second with halothane. The latter anesthesia largely suppressed the "early" postischemic seizures, i.e. those occurring after 1-4 h. Dimethylthiourea treatment altered the clinical outcome after ischemia. Thus, the "late" postischemic seizures appeared milder and occurred significantly later than in untreated animals. The fatal outcome was also delayed since treated animals died after 35.5 +/- 8.2 h (mean +/- SD) of recirculation, as compared to 19.8 +/- 3.6 h of recirculation in control animals. However, all DMTU-treated (and control) animals died. In the first morphological series (isoflurane anesthesia) the histopathological analysis was complicated by the occurrence of prefixation seizures; such seizures were recognized in 4/16 animals. When these 4 animals were excluded from the analysis (2 treated and 2 control animals), DMTU pretreatment did not ameliorate the damage, except in the substantia nigra pars reticulata (P < 0.05). In the second series, comprising animals anesthetized with halothane, only one animal out of 16 had "early" seizures, and none showed "late" seizures before death. Among these animals DMTU treatment significantly ameliorated damage to caudoputamen and cingulate cortex (P < 0.01). We conclude that treatment with the free radical scavenger DMTU partly ameliorates ischemic brain damage associated with excessive acidosis, and marginally delays the development of post-ischemic seizures. However, the effects were moderate and could, at least in part, have been caused by nonspecific effects of DMTU. Furthermore, all DMT

Topics: Animals; Blood Glucose; Cerebrovascular Circulation; Free Radical Scavengers; Hyperglycemia; Ischemic Attack, Transient; Male; Prognosis; Rats; Rats, Wistar; Thiourea

The present study was undertaken to determine the effect of exogenous histamine and histamine blockers on blood glucose and hepatic glycogen in the rat. Forty-one nonfasted male Sprague-Dawley rats that had been anesthetized with intraperitoneal injections of urethane were injected intravenously (femoral) with histamine (10 mg/kg) five minutes after pretreatment with Ringer's solution (control), diphenhydramine (1 mg/kg) (H-1 blocker); metiamide (1 mg/kg) (H-2 blocker); or a combination of these blockers. Mean arterial pressure (carotid), blood glucose, and hepatic glycogen were measured. Within 30 minutes, histamine evoked a significant increase in blood glucose, and a decrease in hepatic glycogen, and a reduction in blood pressure. However, rats treated with the H-2 blocker metiamide or with a combination of H-1 and H-2 blockers did not show as significant a hypotensive response as rats treated with the H-1 blocker diphenhydramine alone. The hyperglycemic-glycogenolytic response to histamine was modified by diphenhydramine as well as by a combination of blockers, but not by metiamide alone. These results suggest that a) the hypotension did not initiate the hyperglycemic and glycogenolytic response; b) the H-2 blocker metiamide has little effect on the hyperglycemic response to exogenous histamine; and c) the H-1 blocker diphenhydramine may have antihyperglycemic properties.

Topics: Animals; Blood Glucose; Blood Pressure; Diphenhydramine; Drug Therapy, Combination; Histamine; Hyperglycemia; Isotonic Solutions; Liver Glycogen; Male; Metiamide; Rats; Rats, Inbred Strains; Ringer's Solution; Shock; Thiourea

Topics: Adolescent; Adrenergic beta-Antagonists; Adrenocorticotropic Hormone; Adult; Aged; Female; Guanethidine; Humans; Hydrocortisone; Hyperglycemia; Hyperthyroidism; Iodides; Male; Middle Aged; Reserpine; Steroids; Thiourea; Thyroid Crisis; Thyroid Function Tests; Thyroid Hormones