A flow cytometric method for determination of the interferon receptor IFNAR2 subunit in peripheral blood leukocyte subsets.

INTRODUCTION: It is expected that expression levels in the peripheral blood mononuclear cells (PBMC) of IFNAR2, a subunit of the interferon (IFN) receptor, may be a marker for predicting IFN response. In the present study, we have established a rapid and convenient method for assaying IFNAR2, using flow cytometry. METHODS: Fifty microliters of whole blood from healthy volunteers was treated with an anti-IFNAR2 antibody and stained with a Fluorescein isothiocyanate (FITC)-conjugated secondary antibody. In addition, the cells were stained with subset-specific antibodies conjugated with phycoerythrin (PE) and PE covalently linked to cyanin 5 at the same time. The mean FITC-fluorescence intensities were analyzed separately by gating on subset-specific regions. RESULTS: IFNAR2 was detected in most lymphocytes, monocytes, and granulocytes, although IFNAR2 expression was higher in the monocytes and granulocytes than in the lymphocytes. The intra- and interdaily variations of IFNAR2 in lymphocytes, monocytes, and granulocytes were small. Among the lymphocyte subsets, IFNAR2 showed high expression in natural killer (NK) cells and low expression in T lymphocytes. The effect of IFN-alpha on IFNAR2 expression was examined in vitro. A down-regulation of IFNAR2 was observed by IFN-alpha above 100 IU/ml. DISCUSSION: This assay may be useful for examining IFNAR2 in various leukocyte subsets, separately, as well as providing a rapid and easy method for monitoring expression of type I IFN receptors.

Novel selective hindlimb vasodilators: synthesis and biological activity of 1-acyl-4-aminopiperidine derivatives.

A series of 6-(4-amino-1-piperidinyl)carbonyl-2(1H)-quinolinones, and their open form derivatives, were synthesized and evaluated for their ability to stimulate femoral artery blood flow (FBF) in the canine hindlimb. All members of this series stimulated FBF, and subsequent experiments revealed that selected members of this series produced minimal changes in coronary blood flow or systemic blood pressure. Compound 25 was the most promising agent in this respect, and clinical trials are now ongoing to evaluate the effectiveness of this drug as a novel treatment for intermittent claudication and Raynaud's phenomenon.

Pathogenesis of obesity by food restriction in OLETF rats-increased intestinal monoacylglycerol acyltransferase activities may be a crucial factor.

UNLABELLED: Obesity was considered to be one of the causes of non-insulin-dependent diabetes mellitus (NIDDM). However, the mechanism responsible for obesity has not yet been fully elucidated. In this study, we first examined the relationship between food intake amount and obesity in a NIDDM model animal, and then we focused on triacylglycerol (TG) synthetase activity, which play important roles in hypertriglyceridemia (HTG) associated with obesity. Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model of NIDDM, characterized by obesity, HTG and insulin resistance. In this study, OLETF rats were allocated to a food-satiated group (satiated) or food-restricted group (to eliminate the effects of hyperphagia on obesity, amount of daily food intake was the same as that in their control strain Long-Evans Tokushima Otsuka (LETO) rats). Changes in body weight, body fat, intraabdominal fat weight, and TG content in liver were measured and biochemical blood tests and activity assay of TG synthetase (monoacylglycerol acyltransferase (MGAT) and diacylglycerol acyltransferase (DGAT)) were performed. RESULTS: (1) The body weight in the restricted OLETF rats was significantly decreased to 71.7% of that in the satiated OLETF rats, which was almost the same value as that in the LETO rats. However, body fat and intraabdominal fat weight were significantly increased in restricted OLETF rats and satiated OLETF rats compared with LETO rats. (2) Plasma TG, insulin, glucose, leptin and hepatic TG content were significantly higher in OLETF rats than the values in LETO rats. (3) MGAT activity in the small intestine from both satiated and restricted OLETF rats was significantly higher than that in LETO rats. DGAT activity in OLETF rats was not significantly different from that in LETO rats. In conclusion, the body fat weight and plasma TG were still significantly accelerated in OLETF rats at the same food intake as LETO rats. MGAT activity in the small intestine from OLETF rats was also significantly higher than those of LETO rats. Therefore, high MGAT activity in the small intestine may play an important role in HTG and obesity, subsequently hastening the development of NIDDM in OLETF rats.