‎Unmixed bipartite graphs have been characterized by Ravindra and‎ ‎Villarreal independently‎. ‎Our aim in this paper is to‎ ‎characterize unmixed $r$-partite graphs under a certain condition‎, ‎which is a generalization of Villarreal's theorem on bipartite‎ ‎graphs‎. ‎Also, we give some examples and counterexamples in relevance to this subject‎.

After pretreatment of rat brain synaptic membranes with adenosine deaminase to remove endogenous adenosine, 2-chloro[3H]adenosine, a stable analog of adenosine, binds to two sites with Kd values of 1.3 and 16 nM and corresponding Bmax values of 207 and 380 fmol/mg of protein. Binding is reversible, and the highest density of sites occurs in enriched synaptosomal fractions. In peripheral tissue,...

The mechanisms that control lipolysis in intra-abdominal fat cells from various primate species, the marmoset (Callithrix jacchus), the baboon (Papio papio), and the macaque (Macaca fascicularis), were compared to those of human intraabdominal fat cells. Selective beta 1- or beta 2-adrenoceptor agonists induced lipolysis in all species. Selective beta 3-agonists (BRL 37344, CL 316243, and SR 58...

1. The rate of noradrenaline-stimulated lipolysis is lower in fat-cells from lactating than from pregnant rats; this difference is eliminated by the addition of adenosine deaminase [Aitchison, Clegg & Vernon (1982) Biochem. J. 202, 243-247]. 2. The activity of 5'-nucleotidase, and hence the capacity of the cells to synthesize adenosine, was the same in fat-cells and also stromal cells of adipos...

The density of adenosine receptors in membranes derived from rat hearts is 25 times lower than the density of receptors in rat brain membranes. Consequently, adenosine radioligands which are useful in brain such as /-[HJphenylisopropyladenosine, [H]cydohexyladenosine/ [H]-2-chloroadenosine and f-[I]hydroxyphenylisopropyladenosine are of limited usefulness in heart, due to a high ratio of nonspe...

1. Adipocytes were isolated from the interscapular brown fat of male rats maintained at 21 degrees C. These animals were controls, streptozotocin-diabetics or 2-day insulin-treated diabetics. 2. With adipocytes from diabetic animals, maximum rates of noradrenaline-stimulated O2 uptake were decreased by 58%, and the Bmax. of [3H]GDP binding to mitochondria was decreased by 55%. Insulin administr...

Exposure to phospholipase C increased the incorporation of [32P]Pi into phosphatidate, CMP-phosphatidate and phosphatidylinositol in rat adipose tissue and isolated adipocytes. A similar effect was observed in response to insulin and oxytocin. Theophylline, 3-isobutyl-1-methylxanthine and adenosine deaminase decreased [32P]Pi incorporation, and adenosine and N6-phenylisopropyladenosine reversed...