Mechanism by which a novel non-thiazolidinedione peroxisome proliferator-activated receptor gamma agonist, FK614, ameliorates insulin resistance in Zucker fatty rats

AIM

The aim of this study was to examine the mechanism by which a novel non-thiazolidinedione (TZD) peroxisome proliferator-activated receptor (PPAR) gamma agonist, FK614, ameliorates insulin resistance in Zucker fatty rats.

METHODS

FK614 (1, 3.2 or 10 mg/kg) and a TZD PPARgamma agonist, pioglitazone (1, 3.2 or 10 mg/kg), were orally administered to Zucker fatty rats (genetically obese and insulin resistant) once a day for 14 days, and an oral glucose tolerance test was performed. The expression levels of various genes in the white adipose tissue (WAT) of Zucker fatty rats treated with FK614 (3.2 mg/kg), pioglitazone (10 mg/kg) and another TZD PPARgamma agonist, rosiglitazone (3.2 mg/kg), were determined using a real-time reverse transcription-polymerase chain reaction method. Morphometric analysis of the WAT of Zucker fatty rats treated with FK614 (3.2 mg/kg) and pioglitazone (10 mg/kg) was performed. Glucose transport activity in the isolated soleus muscle of FK614-treated Zucker fatty rats was also investigated.

RESULTS

FK614 and pioglitazone both improved glucose tolerance in Zucker fatty rats. FK614 significantly increased the expression levels of acyl CoA oxidase, a PPAR-responsive gene, and adipocyte fatty acid-binding protein (aP2), an adipocyte differentiation marker gene, in epididymal WAT. It also significantly decreased the level of gene expression of tumour necrosis factor-alpha, an insulin resistance-inducing factor in retroperitoneal WAT, as did pioglitazone and rosiglitazone. FK614 and pioglitazone both significantly increased the total number of adipocytes and decreased their average size in WAT, mainly by increasing the number of small adipocytes. Additionally, administration of FK614 to Zucker fatty rats enhanced insulin sensitivity for glucose uptake in the soleus muscle.

CONCLUSION

This study suggests the possibility that FK614 induces adipocyte differentiation in Zucker fatty rats by stimulating PPARgammain vivo, thereby changing the character of WAT and improving insulin sensitivity throughout the body.

Tacrolimus (FK506) attenuates biphasic cytochrome c release and Bad phosphorylation following transient cerebral ischemia in mice

Tacrolimus (FK506) has a neuroprotective action on cerebral infarction produced by cerebral ischemia, however, detailed mechanisms underlying this action have not been fully elucidated. We examined temporal profiles of survival-and death-related signals, Bad phosphorylation, release of cytochrome c (cyt.c), activation of caspase 3 and DNA fragmentation in the brain during and after middle cerebral artery occlusion (MCAo) in mice, and then examined the effect of tacrolimus on these signals. C57BL/6J mice were subjected to transient MCAo by intraluminal suture insertion for 60 min. Tacrolimus (1 mg/kg, i.p.) was administered immediately after MCAo. There were biphasic increases in the release of cyt.c in the ischemic core and penumbra; with the first increase toward the end of the occlusion period and the second increase 3-12 h after reperfusion. Tacrolimus significantly inhibited the increase of cytosolic cyt.c during ischemia and reperfusion. Phosphorylated Bad, Ser-136 (P-Bad(136)) and Ser-155 (P-Bad(155)) were detected 30 min after MCAo and after reperfusion in the ischemic cortex, respectively. Tacrolimus increased P-Bad(136) during ischemia and prolonged P-Bad(155) expression after reperfusion. Tacrolimus also decreased caspase-3 and terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling-positive cells, and reduced the size of infarct 24 h after reperfusion. Our study provided the first evidence that the neuroprotective action of tacrolimus involved inhibition of biphasic cyt.c release from mitochondria, possibly via up-regulation of Bad phosphorylation at different sites after focal cerebral ischemia and reperfusion.

Association of the antagonism of von Willebrand factor but not fibrinogen by platelet alphaIIbbeta3 antagonists with prolongation of bleeding time

BACKGROUND

The alphaIIbbeta3 antagonists inhibit platelet aggregation and are used as antithrombotic agents for cardiothrombotic disease. The present study investigates the correlation of inhibition of fibrinogen and von Willebrand factor (VWF) binding by alphaIIbbeta3 antagonists with the inhibition of platelet aggregation and prolongation of bleeding time (BT).

METHODS

Inhibition of fibrinogen and VWF binding were assessed in a purified alphaIIbbeta3-binding assay. As an in vitro cell-based assay, platelet aggregation and VWF-mediated adhesion studies were performed using human platelets. In vivo effects on BT were measured using a template device in dogs at the same time as an ex vivo aggregation study was performed.

RESULTS

In vitro studies demonstrated that the antiaggregatory effects of alphaIIbbeta3 antagonists correlate with their inhibition of fibrinogen binding, but not VWF. Interestingly, the effects of alphaIIbbeta3 antagonists on BT could be differentiated from the inhibition of platelet aggregation. Furthermore, this differentiation was strongly correlated with the different inhibitory potencies between fibrinogen and VWF binding, as well as that between VWF-mediated adhesion and aggregation.

CONCLUSIONS

Our study provides novel evidence showing that the inhibitory effect of alphaIIbbeta3 antagonists on VWF, but not fibrinogen binding, correlates with their ability to prolong BT.

A review of the action of tacrolimus (FK506) on experimental models of rheumatoid arthritis

Tacrolimus (FK506) is an immunosuppressive drug, widely used for organ transplantation and atopic dermatitis. Tacrolimus exerts its immunosuppressive effects primarily by interfering with the activation of T cells, via inhibition of calcineurin. Recent clinical studies have also demonstrated the efficacy of tacrolimus in the treatment of rheumatoid arthritis (RA), an autoimmune disease in which T cells play a pivotal role in pathogenesis. Inflammatory cytokines such as TNF-alpha, IL-1 beta, and IL-6 are involved in development of the disease. Recently, modes of action of tacrolimus on RA have been intensively studied in in vitro and animal arthritis models, demonstrating that tacrolimus exerts various novel actions as an anti-rheumatic drug. The pharmacological action of tacrolimus suggests that it has potential to specifically suppress the production of pathogenic inflammatory cytokines with a low frequency of infection, improve joint inflammation and bone/cartilage destruction, fully recover loss of functional status, exert rapid relief in arthritic pain, and promote osteogenic and chondrogenic differentiation. Here we review the action of tacrolimus on experimental models of RA, with a focus on our recent studies, and provide further insight into experimental models used for identifying efficacious anti-rheumatic drugs.

Comparison of anti-arthritic properties of leflunomide with methotrexate and FK506: effect on T cell activation-induced inflammatory cytokine production in vitro and rat adjuvant-induced arthritis

OBJECTIVE AND DESIGN

To examine the effect of leflunomide (LEF) on T cell activation-induced inflammatory cytokine production in human peripheral blood mononuclear cells (PBMC) and rat established adjuvant-induced arthritis (AIA), and compare these effects with methotrexate (MTX) and FK506 (tacrolimus), focusing on improvement of joint function in AIA.

METHODS

Human PBMC were cultured with immobilized anti-CD3/CD28 monoclonal antibody to produce tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6. The active metabolite of LEF was used in in vitro study. AIA was induced in female Lewis rats. Paw swelling and grip strength were measured as indicators of arthritis and joint function, respectively. Rats were therapeutically administered LEF (3.2-32 mg/kg) from days 15-24 by oral administration.

RESULTS

LEF inhibited anti-CD3/CD28 induced production of TNF-alpha, IL-1beta and IL-6, with IC50 values of 27, 21 and 21 microg/ml, respectively. LEF also suppressed mouse bone marrow cell MTT conversion, with an IC50 value of 15 microg/ml. LEF significantly inhibited paw swelling and loss of grip strength in established AIA at 10 and 32 mg/kg. The inhibition of paw swelling and grip strength loss by LEF was more potent than MTX. However, maximum recovery of grip strength loss by LEF (23.5%) was less potent compared to that with FK506 (57.8%).

CONCLUSIONS

LEF inhibited anti-CD3/CD28 induced inflammatory cytokine production in human PBMC at concentrations showing deleterious effects on bone marrow cell proliferation. LEF is superior to MXT in improving arthritis and joint function in established AIA, but is inferior to FK506 in recovering joint function, probably due to its anti-proliferative actions.

Inflammatory cytokine levels in paw tissues during development of rat collagen-induced arthritis: Effect of FK506, an inhibitor of T cell activation

OBJECTIVE AND DESIGN

To characterize rat collagen-induced arthritis (CIA) on the basis of levels of inflammatory cytokines, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 in paw tissues, and further investigate the effect of FK506 (tacrolimus), a potent inhibitor of T cell activation, on cytokine levels.

METHODS

CIA was induced in female Lewis rats. The volume of hindpaws was measured before and after collagen immunization. TNF-alpha, IL-1beta and IL-6 levels in paw tissue extracts were determined by ELISA. Proteoglycan contents of cartilage in femoral heads was measured as an indication of cartilage destruction. To assess the effect of FK506 on inflammatory cytokine levels, rats were orally treated with 5 mg/kg of FK506 from days 14-21.

RESULTS

TNF-alpha a level in paw tissues did not significantly change compared to levels found before collagen immunization, throughout development of CIA. In contrast, IL-1beta and IL-6 levels in paw tissues significantly increased between day 14 and day 28 after collagen imuninization, when the arthritis was at a developed stage. Therapeutic treatment with FK506 reduced the elevated level of IL-6, but not IL-1beta, in paw tissue. FK506 treatment was effective in suppressing paw swelling and also recovering the loss of proteoglycan contents in the cartilage.

CONCLUSIONS

Levels of IL-1beta and IL-6, but not TNF-alpha , in paw tissue were upregulated in association with the development of arthritis in rat CIA. These results suggest that IL-1beta and IL-6, rather than TNF-alpha , may play important roles at local inflammatory sites in producing joint destruction in rat CIA. FK506 may improve arthritis in established stages of CIA, by reducing the elevated level of IL-6.

Effect of FK506 eye drops on late and delayed-type responses in ocular allergy models

BACKGROUND

It is well-known that FK506 strongly inhibits cytokine production by T cells in vitro. However, less evidence is available from in vivo studies of ocular allergy.

OBJECTIVE

To study the anti-inflammatory effect of FK506 eye drops on late and delayed-type responses in several animal models of ocular allergy.

METHODS

Rats and guinea-pigs were sensitized with egg albumin (EA) in adjuvant and later challenged by topical EA application to their eyes to examine the late response. Biopsy specimens of conjunctiva were stained with haematoxylin-eosin or stained for T cells and eosinophils. In addition, rats, rabbits and guinea-pigs were sensitized with complete Freund's adjuvant and later challenged by injecting purified protein derivatives for the delayed-type response. Bulbar conjunctival oedema and hyperaemia were graded by score in rabbits, and Evans blue (EB) extravasation was measured in rats and guinea-pigs. FK506 (0.01-1%) and steroid (0.1%) eye drops were instilled in the eyes of animals several times, before and after challenge.

RESULTS

FK506 eye drops inhibited T cell and eosinophil infiltration in the late response and EB extravasation in the delayed-type response in rats. Also, they inhibited conjunctival oedema, hyperaemia and ocular mucus in the delayed-type response in rabbits. These effects were similar to those of steroid eye drops (betamethasone sodium phosphate, fluorometholone). FK506 eye drops also inhibited inflammatory cell infiltration, the loss of conjunctival epithelium and decrease of goblet cells in the late response as well as EB extravasation in the delayed-type response in guineapigs, a steroid-resistant species.

CONCLUSION

FK506 eye drops inhibit late and delayed-type responses in animal models of ocular allergy.

Anti-arthritic properties of FK506 on collagen-induced arthritis in rats

OBJECTIVE AND DESIGN

To determine the effect of FK506 (tacrolimus) on paw inflammation, TNF-alpha expression in joint, and bone and cartilage destruction in type II collagen-induced arthritis (CIA) model in rats.

METHODS

CIA was induced by immunization of female Lewis rats with an emulsion of bovine type II collagen and incomplete Freund's adjuvant. Paw inflammation was assessed by the increase in paw volume. Tumor necrosis factor (TNF) -alpha expression in hind knee joint was assessed by immunohistochemical analysis. Lesions of bone and cartilage were assessed on the basis of histological change in knee joint, radiographic analysis in hind paw, bone mineral density in femora and proteoglycan contents in the cartilage of femoral heads. FK506 at doses of 1, 1.8 and 3.2 mg/kg or its placebo formulation was orally administered to rats for 28 days from the day after immunization (n = 10). Effect of FK506 was compared with that of vehicle (distilled water).

RESULTS

FK506 at a dose of 1.8 mg/kg significantly suppressed paw swelling (p < 0.01) and histological change in knee joint (p < 0.05). Tumor necrosis factor (TNF)-alpha was mainly expressed in the region with a marked infiltration of inflammatory cells in the hind knee joint. FK506 (3.2 mg/kg) markedly reduced TNF-alpha expression. FK506 at a dose of 1.8 mg/kg suppressed radiographic changes in hind paw (p < 0.05) and also recovered the decrease in bone mineral density in the femora (p < 0.05). Proteoglycan contents in the cartilage of femoral heads were determined to evaluate the cartilage destruction more quantitatively and found to significantly decrease in CIA rats. FK506 at a dose of 1.8 mg/kg recovered the loss of proteoglycan contents (p < 0.01).

CONCLUSION

These results show that FK506 is effective in suppressing inflammation, TNF-alpha expression in joint, and damage to bone and cartilage in rat CIA, and may be useful in the treatment of rheumatoid arthritis.

Insulin-like growth factor-I enhances choleretic action of FK506 in rats

FK506 is an immunosuppressant for organ transplantation in the same clinical settings as cyclosporine (CsA). In the management of liver transplantation, FK506 has advantages over CsA, in terms of rejection and corticosteroid requirements. Recent clinical findings in liver transplant patients indicate that FK506, but not CsA, stimulates choleresis, suggesting that FK506 treatment may accelerate recovery from cholestatic dysfunction through its choleretic action. Recently, we demonstrated in rats that exogenous treatment with insulin-like growth factor I (IGF-I) results in an increase in bile flow and also that FK506 has the potential to increase hepatic production of IGF-I. However, circulating levels of IGF-I in FK506-treated rats were only 30% higher than in nontreated rats. In this study, we evaluated the combined effect of treatment with both IGF-I and FK506 on bile flow in rats to explore the possibility that combination treatment in liver transplant patients could enhance the choleretic action of FK506, benefiting the transplanted liver. Combination treatment of IGF-I with FK506 resulted in a potent and long-lasting increase in bile flow. Overall, this study demonstrated that IGF-I treatment enhanced the choleretic action of FK506, providing potential clinical utility for combination therapy using these two drugs, in treatment after liver transplantation.

UVB IRRADIATION SUPPRESSES CYTOKINE PRODUCTION AND INNATE CELLULAR IMMUNE FUNCTIONS IN MICE

We examined whether ultraviolet-B (UVB) irradiation (6 kJ/m2) alters cytokine production and other innate immune reactions by murine peritoneal macrophages and peripheral neutrophils. Along with these experiments, serum IgG levels were also assessed. In addition, using scanning electron microscopy (SEM) we observed macrophages that had been exposed to UVB in vitro. Results showed that UVB irradiation: (1) decreased IL-12 production while increasing IL-1alpha secretion from macrophages, but had no effect on IL-1alpha from neutrophils; (2) suppressed phagocytosis of macrophages but not of neutrophils; (3) diminished active oxygen production of macrophages but not of neutrophils; (4) had no effect on serum IgG levels; and (5) caused significant cell destruction of macrophages in vitro. These results suggested: (1) that UVB irradiation could induce characteristic suppression of innate immunity; (2) that innate cellular immunity was more susceptible to the effects of UVB irradiation than humoral immunity.

The effects of zenarestat, an aldose reductase inhibitor, on peripheral neuropathy in Zucker diabetic fatty rats

We studied the effects of zenarestat, an aldose reductase inhibitor (ARI), on peripheral neuropathy in Zucker diabetic fatty (ZDF) rats, an animal model of type 2 diabetes. ZDF rats and their lean rats counterparts were fed a sucrose-containing diet, and zenarestat was given orally once a day for 8 weeks. Motor nerve conduction velocity (MNCV), F-wave minimal latency (FML), and sorbitol concentrations in the sciatic nerve were measured. In ZDF control rats, a remarkable accumulation of sorbitol, a delay in FML, and a slowing of MNCV were observed compared with lean rats. At a dose of 3.2 mg/kg, zenarestat had no significant effect on the delay in FML and the slowing of MNCV, although the sorbitol accumulation in the sciatic nerve was partially inhibited in ZDF rats. On the other hand, 32 mg/kg zenarestat treatment improved these nerve dysfunctions in ZDF rats, along with a reduction of nerve sorbitol accumulation almost to the level of lean rats. These data showed that zenarestat improved diabetic peripheral neuropathy in ZDF rats, a type 2 diabetes model, providing evidence for the therapeutic potential of zenarestat for the treatment of diabetic neuropathy.

Alteration in expression profiles of a series of diabetes-related genes in db/db mice following treatment with thiazolidinediones

We studied the effect of pioglitazone on the transcription of 42 genes associated with diabetes to examine the relationship between the antidiabetic action of thiazolidinediones (TZDs) and their ability to modulate transcription through their peroxisome proliferater-activated receptor (PPAR)-agonistic activity. Diabetic (db/db) mice were orally administered with pioglitazone for two weeks. Total RNA was prepared from liver, muscle and adipocytes and the quantity of mRNA was determined by comparative RT-PCR. The expression of diabetes-related genes was compared between lean and untreated db/db mice and between untreated and drug-treated db/db mice. The onset of diabetes was associated with a considerable alteration in the expression of a large number of diabetes-related genes. Treatment of db/db mice with pioglitazone modulated the expression of genes involved in the metabolism of glucose, lipids and lipoproteins. This included genes for phosphoenolpyruvate carboxykinase, beta-oxidation enzymes, lipoprotein lipase, apolipoprotein AI and uncoupling proteins. Most of the genes responsible for insulin signaling were unaffected. Administration of pioglitazone was also shown to induce PPARgamma expression in liver and muscle. It is therefore possible to hypothesize that TZDs may ameliorate diabetes through a mechanism of action involving a direct decrease in plasma glucose and triglyceride levels and improvements in free fatty acid-induced insulin resistance.

Possible involvement of corticosterone in bone loss of genetically diabetic db/db mice

The etiology of bone loss in non-insulin dependent diabetes mellitus is still unknown. We compared serum biochemical parameters and bone parameters of genetically diabetic db/db mice with those of their control non-diabetic +/+ mice. We found that serum corticosterone levels of the db/db mice were significantly elevated after 5 weeks while bone mineral density of femur metaphysis significantly decreased in the db/db mice after 12 weeks of age compared with age matched +/+ mice. To explore the causal relationship between the serum corticosterone levels and the bone loss, metyrapone (100 mg/kg, p.o., twice a day), a glucocorticoid synthesis inhibitor, was administered to these mice for 4 weeks after the age of 8 weeks. The compound significantly decreased serum corticosterone levels in both strains. Metyrapone prevented bone loss by increasing the bone mineral content of the metaphysis in the db/db mice. In addition, the treatment slightly improved the ratio of ash weight to dry weight in the db/db mice. These results suggest that increased serum corticosterone levels are concerned with the etiology of bone loss in non-insulin dependent diabetic db/db mice.

Probable involvement of the 5-hydroxytryptamine(4) receptor in methotrexate-induced delayed emesis in dogs

Delayed emesis in cancer patients undergoing chemotherapy remains a significant problem. The pathogenesis of delayed emesis is still obscure. It was recently demonstrated that methotrexate (MTX), an anticancer drug, evoked delayed emesis in dogs in a manner similar to its actions in humans. We evaluated the antiemetic activity of FK1052, a potent antagonist for both the 5-hydroxytryptamine (HT)(3) and 5-HT(4) receptors, on delayed emesis induced by MTX in beagle dogs. Animal behavior was recorded for 3 days using a video camera. Delayed emesis lasting up to 72 h was observed in dogs treated with MTX (2.5 mg/kg i.v.), but acute emesis did not occur. The following antiemetics, at the dose that prevents cisplatin-induced acute emesis in dogs, were administered i.v. as multiple injections every 12 h during days 2 to 3. FK1052 (1 and 3.2 mg/kg) significantly reduced the emetic episodes caused by MTX, whereas ondansetron (1 mg/kg), a selective 5-HT(3) receptor antagonist, was not effective. The emetic episodes induced by MTX were also inhibited by another 5-HT(3/4) receptor antagonist, tropisetron (1 mg/kg). CP-122,721 (0. 1 mg/kg), a potent selective tachykinin NK(1) receptor antagonist, significantly reduced the emetic responses to MTX. Copper sulfate-induced emesis in dogs was also prevented by FK1052, tropisetron, and CP-122,721 but not by ondansetron. FK1052, tropisetron, and ondansetron had negligible affinity for the NK(1) receptor at 1 microM. These results suggest that the 5-HT(4) receptor may be in part involved in the production of delayed emesis induced by MTX in dogs and that FK1052 may be a useful drug against both acute and delayed emesis induced by cancer chemotherapy.

[Immunomodulatory effect of daily low-dose cisplatin treatment]

Immunomodulatory effects of daily low-dose cisplatin treatment were investigated on compromised patients with advanced or recurrent gastrointestinal cancer. One case of esophageal cancer, 7 of gastric cancer, 2 of colorectal cancer, 1 of carcinomatous peritonitis from unknown origin, and 1 of hepatocellular carcinoma, were treated by daily low-dose cisplatin combined with 5-FU or tegafur, and their ECOG Performance Status Score (PS), number of lymphocytes, and CD3 zeta chain expression of peripheral blood lymphocytes were studied to compare with the effects of treatment. Seven patients with esophageal cancer and gastric cancer showed a partial response and their PS was improved, and the number of lymphocytes and CD3 zeta chain expression of lymphocytes was increased. However, in two patients with progressive disease, a decreased number of lymphocytes and less expression of CD3 zeta chain were seen.

Evidence for the presence of regional differences in the subtype specificity of muscarinic receptors in rabbit lower urinary tract

To elucidate the subtype specificity of muscarinic cholinergic receptors in mediating contractile responses in the lower urinary tract, we investigated contractile and biochemical properties of muscarinic receptors in bladder dome, bladder base and urethra of the rabbit. Isometric contractile response curves to increasing concentrations of carbachol were constructed in the absence and presence of various concentrations of subtype selective muscarinic antagonists. Bladder dome, bladder base, and urethra demonstrate different characteristics in terms of efficacy and potency with respect to carbachol-induced contractile responses. Emax values are significantly larger and ED50 values are significantly smaller in bladder dome and bladder base than in urethra. Calculation of the pA2 values, the negative logarithm of the antagonist affinity constant (KB), for a series of muscarinic antagonists, i.e., atropine (nonselective), pirenzepine (M1 selective), methoctramine (M2 selective), and 4-DAMP (M1/M3 selective) indicate that the carbachol-induced contractile response in bladder dome and bladder base is mediated through the M3 receptor subtype whereas the carbachol-induced contractile response in urethra is probably mediated through the M1 and/or M3 and possibly M2 subtypes. Muscarinic cholinergic antagonists inhibit [3H]quinulidinyl benzilate binding to bladder dome, bladder base and urethra with the following rank order of affinities: atropine > 4-DAMP > methoctramine > pirenzepine. The binding data indicate the predominance of the M2 receptor subtype in all three regions.

Experimental IgA nephropathy induced by coxsackie B4 virus in mice

Viruses have been suspected to be etiological agents of IgA nephropathy. Recently, viruses were detected in renal tissues from patients with IgA nephropathy. We tried to cause lesions similar to IgA nephropathy by inoculating virus into mice and to detect virus RNA in the lesion by in situ hybridization. A group of mice were inoculated intravenously with coxsackie B4 virus once a month from 1 to 5 months of age and sacrificed monthly from 6 to 12 months of age. Mesangial proliferation and deposits that stained positive with periodic acid-Schiff in light microscopy and electron-dense deposits in electron microscopy were found from 6 months of age. Positive findings for IgG and IgA deposition in the mesangium were noted and the intensity of IgA deposition was predominant after 10 months of age. The signals of coxsackie B4 virus by in situ hybridization were observed in the lesions. These observations indicate that coxsackie B4 virus inoculated repeatedly into mice induces lesions similar to IgA nephropathy. The depositions of the lesions may be immune complexes of coxsackie B4 virus and these immune complexes injure renal tissues.

Effects of FR145237, an acyl-CoA:cholesterol acyltransferase inhibitor, on diet-induced hypercholesterolemia in diabetic rats

Recent studies have shown that acyl-CoA:cholesterol acyltransferase (ACAT) plays an important role in the initiation of diabetes-associated hypercholesterolemia. To confirm this hypothesis, effects of a potent ACAT inhibitor, FR145237, on diet-induced hypercholesterolemia were examined in streptozotocin (STZ)-induced diabetic rats. One-week feeding of 1% cholesterol and 0.5% cholic acid to normal rats and STZ-induced diabetic rats increased plasma cholesterol levels in both groups, and the response was more remarkable in the STZ rats than in the normal ones (1266 +/- 476 mg/dl and 146 +/- 7 mg/dl, respectively). FR145237 dose-dependently reduced the rise in plasma cholesterol levels in the STZ rats and the levels were almost normalized by treatment with 1 mg/kg/day of the compound. These results suggest that hyperresponse to dietary cholesterol was induced in the STZ rats and that ACAT is involved in the hyperresponse. The effects of FR145237 on other plasma lipids such as high density lipoprotein (HDL) cholesterol and triglyceride (TG) levels were also examined.

Anomalous systemic arterial supply to normal basal segments of the left lower lobe. A report of two cases

Two cases of anomalous systemic arterial supply to the basal segments of the lower lobe of the left lung without sequestration are presented. In the first case, the final diagnosis was made during a surgical operation, and lobectomy of the lower lobe of the left lung was performed. In the second case, the preoperative diagnosis made by CT was confirmed by angiography. An anastomosis was performed between the anomalous artery and the pulmonary artery without resection of the basal segments. Six months after surgery, pulmonary angiography showed improved flow of the anastomosed vessel, but little improvement was evidenced in the perfusion scan.

Plasma cholesterol reducing effect of FR129169, a novel acyl-CoA:cholesterol acyltransferase inhibitor, in the rat

FR129169 (FR) (N-(1,2-diphenylethyl)-2-octyloxyphenylacetamide) has been found to inhibit acyl-CoA:cholesterol acyltransferase (ACAT) activities in intestinal microsomes of rats and rabbits and the liver homogenate of rats with IC50 values of around 1.0 x 10(-7) M. The inhibitory activity was 2-3 times more potent than that of CI 976 (CI). When FR in a dose of 10 mg/kg/day was administered as a dietary admixture, plasma cholesterol levels were normalized in rats fed a high cholesterol diet, but lower doses of FR had no effect. Similar results were obtained in the rats treated with CI. The ex vivo study where hepatic ACAT activity was measured after oral dosing of the two inhibitors revealed that ACAT activity was significantly reduced in rats treated with FR in a dose of 10 mg/kg/day, while CI reduced the activity at lower doses such as 0.1 and 1 mg/kg/day. Since FR was not orally absorbed, it is speculated that the inhibitory activity of FR on hepatic ACAT in the ex vivo study results from the reduction of plasma cholesterol levels. These results suggest that FR exerted cholesterol-lowering activity mainly through inhibition of intestinal ACAT activity. The significance of intestinal ACAT inhibition by FR for therapeutic treatment of hypercholesterolemia is discussed.

Plasma homovanillic acid levels and therapeutic outcome in schizophrenics: comparisons of neuroleptic-naive first-episode patients and patients with disease exacerbation due to neuroleptic discontinuance

Plasma homovanillic acid (pHVA) levels were measured and the Brief Psychiatric Rating Scale (BPRS) scores were evaluated in 26 schizophrenic patients who had either never been medicated (neuroleptic-naive, first-episode subjects) or whose condition had become exacerbated following neuroleptic discontinuance (exacerbated subjects). All the subjects received medication with a fixed dose of a neuroleptic (haloperidol or fluphenazine, both 9 mg/day) for the first week and variable doses for the subsequent 4 weeks. In the neuroleptic-naive subjects, pHVA levels increased significantly 1 week after starting the protocol; this increase correlated significantly with clinical improvement of the BPRS positive symptom scores at week 5. In the neuroleptic-naive subjects, pHVA levels had declined to the baseline level by week 5. In the exacerbated subjects, there were no significant correlations between pHVA level changes at week 1 and later improvements of the BPRS positive symptom scores. These results suggest that the rise in pHVA levels occurring within 1 week after starting a fixed neuroleptic dose may predict a favorable clinical response in neuroleptic-naive schizophrenic patients.

Osteopenia in genetically diabetic DB/DB mice and effects of 1alpha-hydroxyvitamin D3 on the osteopenia. Basic Research Group

To explore the pathogenesis of non-insulin-dependent diabetes mellitus associated osteopenia, we examined age-related changes of the femur metaphyseal bone mineral density in genetically diabetic (db/db) mice and non-diabetic (+/+) mice of the same strain using single photon absorptiometry and characterized the osteopenia pharmacologically and biochemically. Bone mineral density increased with age in the +/+ mice from 5 to 16 weeks of age, but reached a plateau in the db/db mice at 8 weeks of age, and significant differences between the two groups were observed after 12 weeks of age. Ash weight (A) and dry weight (D) of the femur and A/D ratio were significant lower in the db/db mice than in the +/+ mice after 8 weeks of age. Significant elevations of serum calcium and parathyroid hormone (PTH) were observed after 8 weeks and 12 weeks of age, respectively. Serum 1alpha,25-dihydroxyvitamin D levels were significantly decreased in the db/db mice compared to the +/+ mice. Daily oral treatment with 1alpha-hydroxyvitamin D3 (1alpha-(OH)D3) for 4 weeks starting from 8 weeks of age significantly attenuated the bone loss in the db/db mice. These results suggest that an impaired bone mineralization probably by insufficient vitamin D activity and high PTH levels are involved in the osteopenia in the db/db mice. 1alpha-(OH)D3 exerted beneficial effects on the bone loss.

Perirenal mass of Langerhans cell histiocytosis

A 15-month-old girl with Langerhans cell histiocytosis (LCH), Letterer-Siwe disease, was referred to our hospital in 1984. Whilst on treatment with cytotoxic drugs, a perirenal mass was detected and hydronephrosis became evident when she was 29 months old. Percutaneous nephrostomy tubes were placed in the pelvis, bilaterally and replaced every 6 months. The mass was not completely controlled and chronic pyelonephritis continued. Biopsy of the mass convoluted kidney hilus revealed histiocytic invasion. Although multiple organ systems are involved in LCH and abdominal malignant tumours may be accompanied by hydronephrosis, to our knowledge, this is the first case report of abdominal LCH and the ensuing hydronephrosis. Percutaneous nephrostomy tubes proved useful, but more convenient, less painful and infection-limited approaches need to be designed.

Possible involvement of vitamin D3-deficiency and relatively enhanced bone resorption in the development of bone loss in streptozotocin-induced diabetic rats

To explore the pathogenesis of diabetes associated osteopenia, we characterized the osteopenia in streptozotocin (STZ)-diabetic rats pharmacologically and biochemically. The femur metaphyseal bone mineral density measured by single photon absorptiometry decreased time-dependently in the STZ rats compared with that in control, and the difference reached statistical significance from 2 weeks after treatment with STZ. Closely similar bone loss was obtained in ovariectomized (Ovx) and vitamin D deficient(D(-)) rats. Daily oral treatment with a bone resorption inhibitor, FR78844 (a bisphosphonate compound, 100 mg/kg), for 4 weeks significantly attenuated the osteopenia in the STZ and Ovx rats, but not in the D(-) rats, while 1 alpha-hydroxyvitamin D3 (1 alpha-(OH)D3) significantly attenuated the osteopenia in the STZ and D(-) rats in a dose of 0.1 microgram/kg/day, and that in the Ovx rats in 1 microgram/kg/day. The latter dose of 1 alpha-(OH)D3 significantly increased the metaphyseal bone mineral density of the femur in normal rats. Serum levels of 1 alpha, 25-dihydroxyvitamin D (1 alpha, 25-(OH)2D), the most active metabolite of vitamin D, hardly changed in the Ovx rats compared with that in control, but decreased to 24 and 76% that of control in the STZ and D(-) rats, respectively. Serum PTH levels in the STZ, Ovx and D(-) rats were comparable with those in controls, but serum calcitonin levels were reduced to 60 and 66% of control in the STZ and Ovx rats, respectively. Serum osteocalcin levels also decreased in the STZ rats compared to control. It is thus speculated that the predominance of bone resorption over bone formation and the reduction of 1 alpha, 25-(OH)2D are involved in the pathogenesis of diabetes associated osteopenia.

Detection of coxsackie B4 virus RNA in infected mouse kidneys by in situ hybridization

We describe a method for detecting virus-specific RNA sequences using a nonradioactive enzyme system, and analyze coxsackie B4 virus (cox.B4) RNA sequences in infected mouse kidney with pathological changes. Diffuse mesangial proliferation was observed transiently 24 h after inoculation of cox.B4 virus in glomeruli. OCT-treated thin sections of the same tissue were hybridized in situ using a digoxigenin-labeled oligonucleotide probe. The strongest signal was observed in the mesangial sample. These findings suggest that the transient proliferative mesangial changes were caused by direct injury following virus infection without immune complex.

Characterization of heparin-induced osteopenia in rats

Heparin has been known to induce osteopenia, but its precise mechanism of action is unknown. In the present study, we examined the effect of heparin on the rat femur using single photon absorptiometry and characterized the osteopenia biochemically and pharmacologically. Daily heparin injection dose dependently induced osteopenia in rats. Significant bone loss was observed from 2 weeks after starting heparin treatment (2000 U/kg.day) and peaked at 4 weeks. Serum PTH levels were significantly elevated from 1 week onward after starting heparin treatment, whereas no significant changes were seen in serum total calcium or ionized calcium levels. A bone resorption inhibitor, FR78844 (a bisphosphonate compound), significantly attenuated the heparin-induced osteopenia, as did 1 alpha-hydroxyvitamin D3; with the latter, the effective dose was 10 times lower than that needed for a similar effect against immobilization and ovariectomy-induced osteopenia, suggesting an up-regulation of 1 alpha, 25-dihydroxyvitamin D3 receptors in the heparin-treated rats. This speculation was supported by the finding that serum 1 alpha, 25-dihydroxyvitamin D levels were significantly decreased by 54% in the heparin-treated rats compared to those in normal rats. These results suggest that the enhanced bone resorption by high PTH blood levels and the reduction of 1 alpha, 25-dihydroxyvitamin D are involved in the pathogenesis of heparin-induced osteopenia.

Heparin increased cell membrane-associated heparan sulfate proteoglycan in balloon-injured rat carotid artery

The effect of heparin on the amount of membrane-associated heparan sulfate proteoglycan (HSPG) was examined biochemically in balloon-injured rat carotid arteries. Heparin (Choay 1772) was administered at the rate of 1 mg/kg/h.i.v. by an osmotic infusion pump for 10 days. Arterial tissues were incubated ex vivo with Na2(35)SO4 and 3H-glucosamine for 6 or 24 h. The arteries from heparin-treated rats were also incubated with heparin (100 micrograms/ml) during the radiolabeling. Membrane-associated proteoglycans were extracted with 4 M guanidine-HCl and isolated by a series of chromatographic steps using Sephadex G-50, DEAE-Sephacel and Octyl-Sepharose CL-4B. Membrane-associated proteoglycans were eluted with 0.8% Triton X-100 from Octyl-Sepharose columns. Heparin treatment significantly increased membrane-associated HSPG by 64% in the arteries incubated for 24 h, while heparin hardly increased the HSPG in 6 h incubated arteries. Since the 24-hour data seem to reflect a combination of biosynthesis and degradation of proteoglycans while the 6-hour data primarily reflect biosynthesis, these results suggest that inhibition of degradation of membrane-associated HSPG is involved in the mechanism of heparin action. This speculation is supported by the observation that membrane-associated HSPG was elevated in balloon-injured arteries by treatment with protease inhibitors.

Local control of prostate cancer by intraarterial infusion chemotherapy facilitated by the use of angiotensin II

Intraarterial infusion chemotherapy with angiotensin II was carried out in 8 prostate cancer patients whose ages ranged from 61 to 77 years. They had stage C or D tumor progression and complained of difficult urination, bone pain or lymphedema caused by intrapelvic tumor infiltration. Endocrine therapy had been done before the infusion therapy but the clinical status showed little change with a persistence of local symptoms. Cis-platinum and doxorubicin were infused with an indwelling catheter into both internal iliac arteries. After the completion of 1-5 courses, 6 of 8 patients responded remarkably in local symptoms. It is thought that intraarterial infusion chemotherapy can be used safely and effectively in elderly patients.

Role of inflammatory responses in initiation of atherosclerosis: effects of anti-inflammatory drugs on cuff-induced leukocyte accumulation and intimal thickening of rabbit carotid artery

Immediately after a cuff-sheathing of rabbit carotid artery, a large number of leukocytes adhered to injured endothelium then infiltrated into the media. These inflammatory responses were followed by an atherosclerotic change, intimal thickening, of the artery. A simultaneous injection of dexamethasone (10 mg/kg i.m.) inhibited the leukocyte accumulation by 74% when evaluated 18 h thereafter. Similarly, 39% inhibition was obtained with the same dose of FR110302, a potent 5-lipoxygenase inhibitor. On the other hand, the same dose of indomethacin, a cyclooxygenase inhibitor, had little effect on the leukocyte accumulation. The intimal thickening which was evaluated 3 weeks after the cuff-treatment was attenuated by a daily dose (10 mg/kg i.m.) of dexamethasone or FR110302 but not by one of indomethacin. The inhibition by the two former drugs were 91 and 58%, respectively. In vitro, the three drugs in concentrations up to 10 microM hardly affected endothelial adhesion of PMN which was induced by LPS or IL-1. Though 10 microM of FR110302 and indomethacin significantly decreased PMN chemotaxis induced by LTB4, the decreases were less than that at 10 microM dexamethasone. These results confirm a possible linkage between inflammation and atherosclerosis, and suggest that 5-lipoxygenase products contribute to the initiation and development of atherosclerosis.

Spinal coning after lumbar puncture in prostate cancer with asymptomatic vertebral metastasis: a case report

A 60-year-old man was admitted to our hospital for complete urinary retention. Prostate cancer was diagnosed and anti-cancer chemotherapy was administered. Regression of prostatic enlargement was appreciated and difficult urination improved. At 6 months after the initial treatment vertebral metastasis of T10-11 was noted on a bone scintigram but there were no symptoms induced by bone metastasis. Orchiectomy was performed with the patient under lumbar anesthesia. Complete paralysis of both lower extremities occurred postoperatively. Computerized tomography and myelographic findings demonstrated complete subarachnoid block with an extramedullary spinal cord tumor. It was concluded that traction on the spinal cord producing neurological deterioration (spinal coning) occurred after removal of the cerebrospinal fluid by lumbar puncture.

Serum levels of coagulation-fibrinolysis factors in normal pregnancy, labor and puerperium and in cesarean section delivery

Plasma levels of fibrinopeptide A (FPA), fibrinopeptide B beta 15-42 (FPB beta 15-42), high molecular weight kininogen (HMW-kg), kinin, prekallikrein and kallikrein inhibitor during pregnancy, labor, cesarean section and puerperium were studied in 170 cases of full term normal delivery and 20 cases of cesarean section delivery with 30 non-pregnant women taken as control. Significant increases of FPA, FPB beta 15-42 and kinin during normal delivery and puerperium were found. There was also a significant increase of FPA in the uterine venous blood during cesarean section. Significant decrease of HMW-kg during normal labor and also significant decrease of prekallikrein and kallikrein inhibitor after cesarean section were also seen. Our findings suggested that the hypercoagulable state during pregnancy is due to the increase of thrombin and plasmin activity, and the kallikrein-kinin system may be related to the onset of labor and post-delivery uterine contraction. Increase of the FPA in the uterine blood promoted localised coagulation activity during cesarean section.

Application of Namalva interferon-alpha monoclonal antibodies for purification and enzyme immunoassay of interferon-alpha

Namalva (or Namalwa) interferon (IFN)-alpha was partially purified using a combination of conventional methods and modified acid-ethanol extraction. Four mouse monoclonal antibodies against Namalva IFN-alpha were prepared by hybridoma technology after immunization with Namalva IFN-alpha thus purified. Three of these monoclonal antibodies recognized the same or a similar epitope on Namalva IFN-alpha. One of these antibodies was paired with the fourth recognizing a different epitope and used respectively as enzyme-conjugated antibody and solid-phase antibody in our one step enzyme immunoassay (EIA) for IFN-alpha. This assay is simple and was able to detect as little as 5 pg of IFN-alpha in 100 microliters of sample in the short time of 5 hr. There was a good correlation between the EIA and bioassay. The use of one of the monoclonal antibodies as an immunoadsorbant to purify Namalva IFN-alpha is also described.

Protective action of a calcium antagonist, nilvadipine, against aortic calcium deposition--a pathogenic factor in atherosclerosis

Nilvadipine and other calcium antagonists were studied for their effect on 1-alpha-hydroxyvitamin D3 (1 - alpha (OH)D3)-induced aortic calcium deposition in rats. The animals were treated orally with 1-alpha (OH)D3 (10 micrograms/kg) for 2 weeks. Calcium antagonists were given orally twice a day during the same period. The aortic calcium content in 1-alpha (OH)D3-treated rats increased to about 100 times that in the control. Nilvadipine reduced the aortic calcium deposition dose-dependently, with percent inhibition of 6, 43, 72 and 92%, at doses of 0.1, 1, 10 and 100 mg/kg, respectively. Similar activities were obtained for the other calcium antagonists except diltiazem which had no effect even at the largest dose of 100 mg/kg. According to the ED50 values, nilvadipine (2.2 mg/kg) was more potent than nifedipine (23.2 mg/kg), nicardipine (12.4 mg/kg) and verapamil (32.0 mg/kg). Scanning and transmission electron microscopy showed clear-cut degenerative changes in the endothelial cells after 1-alpha (OH)D3 treatment. Nilvadipine exerted a protective effect against these degenerative changes but not against 1-alpha (OH)D3-induced hypercalcemia. Furthermore, the drug had only minimal effect on in vitro calcification of the aorta. Our findings suggest that nilvadipine inhibits aortic calcification by protecting the aortic wall cells.

Smooth muscle cell migration induced by inflammatory cell products and its inhibition by a potent calcium antagonist, nilvadipine

The chemotactic activities of inflammatory cell products for rat aortic smooth muscle cells (SMC) were examined in modified Boyden chambers. A checker board analysis revealed that interleukin-1 (IL-1), leukotriene B4 (LTB4), platelet-derived growth factor (PDGF) and inflammatory exudate from zymosan-activated air pouches stimulated chemotaxis of SMC. The chemotaxis, irrespective of the attractants used, was strongly inhibited by nilvadipine, a potent calcium antagonist, and the IC50 values were around 1 x 10(-10) M. Removal of extracellular calcium abolished the chemotactic activities of the attractants. These results suggest that inflammatory cells such as macrophages and polymorphonuclear leukocytes (PMN) have an important role in the migration of SMC into the intima during atherogenesis, and that nilvadipine might be useful for preventing and treating atherosclerosis.

Effect of adrenergic and cholinergic drugs on the noradrenergic transmission in bladder neck smooth muscle

Strips of bladder neck smooth muscle were isolated from the dog and noradrenaline stores in the peripheral sympathetic nerve terminals were labelled with (-)3H-noradrenaline. Transmural electrical stimulation was applied and the released radiolabeled noradrenaline in the superfusate was measured with a liquid scintillation counter. Autonomic drugs were administered in the superfusate to examine their effect on noradrenaline release evoked by electrical stimulation. The general conclusions drawn from the data are that: there are two autonomic receptor systems on sympathetic nerve terminals of bladder neck--alpha-adrenergic receptors and muscarinic receptors, the activation of alpha-adrenergic receptors or muscarinic receptors depresses noradrenaline release and parasympathetic nerve excitement inhibits noradrenaline release in bladder neck.

Inflammatory responses in cuff-induced atherosclerosis in rabbits

Cuff-treatment of the rabbit carotid artery produced a diffuse intimal thickening which resembled early lesions of atherosclerosis. A limited amount of focal endothelial damage occurred first (0.5 h), leukocytes infiltrated the subendothelium and extensive endothelial denudation occurred at 24 h. At 3 days, the regenerating endothelium covered the denuded area, and the media was edematous. At 7 days proliferation of intimal cells became visible. Maximum intimal thickening occurred at 3 weeks. Daily injection of dexamethasone (0.01-10 mg/kg i.m.) and ticlopidine (1-100 mg/kg i.m.) dose-dependently attenuated the intimal thickening. Indomethacin had little effect. Inflammatory exudate from zymosan-activated air pouch induced chemotaxis of rat smooth muscle cells (SMC) in vitro. Similar chemotactic activity was observed with leukotriene B4 (LTB4) but not with the other lipoxygenase products tested. The exudate contained reasonable amounts of LTB4, which would account for its chemotactic activity. Dexamethasone inhibited the chemotaxis by the exudate and proliferation of SMC. These results are discussed in relation to the mechanism of atherogenesis. It is concluded that leukocytes play a major role in cuff-induced intimal thickening, and that their products cause endothelial denudation and SMC chemotaxis. Involvement of platelet aggregation in atherogenesis is also suggested.

Antiatherogenic activity of FR34235 (Nilvadipine), a new potent calcium antagonist. Effect on cuff-induced intimal thickening of rabbit carotid artery

The antiatherogenic activity of FR34235 (Nilvadipine), a calcium antagonist, was examined in rabbits with carotid arteries sheathed with polyethylene cuffs, and compared with that of nifedipine, verapamil and diltiazem. The drugs were given intramuscularly in daily doses of 0.01-10 mg/kg for 3 weeks, starting on the day of cuff-placement. FR34235 dose-dependently inhibited the cuff-induced intimal thickening, and was more potent than the other calcium antagonists, whose order of potency was nifedipine, diltiazem and verapamil. In an in vitro experiment on inhibition of migration of rat aortic smooth muscle cells, using zymosan-activated air pouch exudate as a chemoattractant in modified Boyden chambers, FR34235 was also the most potent among the calcium antagonists tested. The IC50 values were 3.3 X 10(-11) M for FR34235, 1.7 X 10(-10) M for nifedipine, 6.0 X 10(-9) M for verapamil and 2.4 X 10(-7) M for diltiazem. Effects of these drugs on proliferation of rat aortic smooth muscle cells and rabbit platelet aggregation were also examined in vitro. At concentrations less than 10(-5) M, none of the drugs inhibited proliferation of the smooth muscle cells, and only verapamil inhibited collagen-induced platelet aggregation (IC50 = 9.0 X 10(-7) M). It is suggested that FR34235 should be useful for preventing and treating atherosclerosis. Inhibition of smooth muscle cell migration is thought to be its mechanism of antiatherogenic activity.

Pseudohyperaldosteronism (Liddle's syndrome): a case report

A 22-year-old man was hospitalized because of hypertension, hypokalemic alkalosis and suppressed plasma renin activity. Although these findings were similar to hyperaldosteronism, plasma aldosterone concentration and urinary aldosterone excretion were lower than the normal range. Adrenocortical function also was normal except for aldosterone. Treatment with spironolactone, salt restriction and potassium supplementation improved the hypokalemia but not the hypertension. Blood pressure decreased markedly after administration of triamterene.

Enzyme immunoassay of human protein C by using monoclonal antibodies

An enzyme-linked immunosorbent assay (ELISA) for measuring human protein C by using two monoclonal antibodies directed toward the heavy chain of protein C is reported. This assay enabled the determination of protein C in concentrations of 10 to 400 ng/ml in less than 3 hours with a single antigen-antibody reaction. Within-run and between-run coefficients of variation were less than 8%. The mean concentrations of protein C in plasma of 42 normal subjects, 24 patients with liver disease, 27 with DIC, 48 with warfarin therapy and 15 with congenital protein C deficiency, were 4.2, 3.0, 2.3, 2.1 and 1.9 micrograms/ml, respectively. The results obtained with the present ELISA correlated well with those of radioimmunoassay (r = 0.935, n = 81) as well as those of Laurell's Rocket method (r = 0.910, n = 81) by using rabbit anti-human protein C serum. The present method was sensitive and specific for measurement of protein C and also PIVKA-protein C in plasma.

Comparison of the effects of primary prostaglandins on isolated human urinary bladder

The effects of primary prostaglandins (PGs) on the dome and trigone of the human urinary bladder were investigated in vitro. In the dome preparations, PGE1 (10(-9) to 10(-6) gm./ml.) showed a weak contractile effect, while PGE2 (10(-9) to 10(-6) gm./ml.) produced dose-dependent contractions. PGF2 alpha (10(-9) to 10(-6) gm./ml.) induced contractions greater than those induced by PGE1 and PGE2. In the trigone preparations, PGE1 (10(-9) to 10(-6) gm./ml.) had no effect, and PGE2 (10(-9) to 10(-6) gm./ml.) produced only a weak contractile response. PGF2 alpha (10(-9) to 10(-6) gm./ml.) showed a greater contractile potency than PGE2. Contractile responses of both preparations to PGE1, PGE2 and PGF2 alpha were not affected by pretreatments of atropine, hexamethonium and phentolamine. These results suggest that the order of potency of primary PGs to induce contractile responses is PGF2 alpha greater than PGE2 greater than PGE1 in both the dome and the trigone preparations, and that the contractile effects of PGE1, PGE2 and PGF2 alpha may not be mediated by activation of muscarinic, nicotinic or adrenergic alpha-receptors.

Actions of some autonomic drugs on spontaneous contractions of isolated dog ureter

Effects of some autonomic drugs on the isolated dog ureteral preparations showing spontaneous contractions were investigated quantitatively. Noradrenaline, adrenaline and phenylephrine produced increases in frequency and tension of the contractions which were reversed to decreases or depressed by phentolamine. Isoproterenol abolished the spontaneous contractions. Acetylcholine did not significantly change frequency and tension of the contractions. The results indicate that ureteral spontaneous contractions may be enhanced through an activation of alpha-adrenoceptors and be attenuated through an activation of beta-adrenoceptors. However, acetylcholine will not display an important role on the ureteral contractions.

Comparison of sulfation of glycosaminoglycans and glycopeptides from control and virus-transformed baby hamster kidney cells

Sulfation of glycosaminoglycans and glycopeptides was compared in baby hamster kidney (BHK) cells and the polyoma virus transformants (PY-BHK). Cells were incubated with [3H]glucosamine and [35S]sulfate, and the labeled glycosaminoglycans and glycopeptides were isolated by digesting the cell membrane fraction with pronase followed by gel filtration. Each type of glycosaminoglycan in the void volume fraction (Fraction I) and in the included fraction (Fraction II) was determined by sequential enzymatic digestions. The residue was regarded as being glycopeptides. Of the total 3H radioactivities of glycosaminoglycans in Fraction I from BHK cells, 51% were in dermatan sulfate, 23% were in heparan sulfate, 17% were in chondroitin 4- and 6-sulfates, and 9% were in hyaluronate. PY-BHK cells acquired significantly larger amounts of 3H radioactivities in sulfated glycosaminoglycans than did BHK cells on the basis of cell number. On the basis of protein content, there was no such difference due to higher protein content of PY-BHK cells. The degree of sulfation of the glycosaminoglycans, estimated from the ratio of 35S to 3H and by disaccharide analysis, was significantly lower in PY-BHK cells than in BHK cells. Considerable amounts of 35S radioactivities assigned to sulfated glycopeptides were found in Fraction II from both BHK and PY-BHK cells.

A family of hereditary stomatocytosis associated with normal level of Na+-K+-ATPase activity of red blood cells

A rare familial case of hereditary stomatocytosis with hemolytic anemia, increased autohemolysis, increased osmotic fragility, and shortened erythrocyte survival is described. The erythrocytes were abnormally permeable to sodium and potassium. In addition, "Na-K pump" rate of the red blood cells was increased, while Na+-K+-ATPase, Mg2+-ATPase and Mg2+-Ca2+-ATPase activities were within normal limits. Splenectomy induced marked improvement of anemia.