Studies were carried out to assess the role of insulin (I), cortisol (H), and prolactin (P or PRL) in regulating myoinositol (inositol) uptake in the mammary gland. Using cultured mammary gland explants from pregnant mice (12-14 days into gestation), insulin and prolactin were found to stimulate inositol uptake, while cortisol impaired inositol uptake. Optimal inositol uptake was observed when ...

The formation of inositol phosphates in response to secretagogues was studied in rat pancreatic acini preincubated with [3H]inositol. Carbachol caused rapid increases in radioactive inositol phosphate, inositol bisphosphate and inositol trisphosphate . This effect was blocked by atropine, and also elicited by caerulein, but not by ionomycin or phorbol dibutyrate. Thus phospholipase C-mediated b...

Myo-inositol, the precursor of all inositol compounds, is essential for the viability of eukaryotes. Identifying the factors that regulate inositol homeostasis is of obvious importance to understanding cell function and the pathologies underlying neurological and metabolic resulting from perturbation of inositol metabolism. The current study identifies Mck1, a GSK3 homolog, as a novel positive ...

Inositol (me8oinositol or myoinositol) occurs very widely in plants, animals and micro-organisms (Fleury & Balatre, 1947; Courtois, 1951; Hawthorne & Chargaff, 1954; Mann, 1954a). It occurs in the free state as well as in the form of inositol phosphatides, while in plants it is often present as the hexaphosphate, phytic acid. Treatment of liver and nervous tissue by the standard procedure of Sc...

The initial rate of uptake of [3H]myo-inositol by L1210 murine leukaemia cells is directly proportional to the extracellular concentration and unaffected by several analogues of myo-inositol even at millimolar concentrations. Scyllitol, a geometric isomer of myo-inositol, partially inhibited the uptake of myo-inositol (40% at 0.1 mM). A portion of the uptake of myo-inositol was not inhibited ev...

Bovine aortic and cerebral microvascular endothelial cells and cultured segments of canine common carotid artery possess functional receptors for the nonapeptide bradykinin which mediate a rapid increase in the formation of [3H]inositol 1-phosphate, [3H]inositol 1,4-bisphosphate, and [3H]inositol 1,4,5-trisphosphate from cell membranes containing isotopically labeled myo-inositol. Bradykinin st...

Reduction of phytate is a major goal of plant breeding programs to improve the nutritional quality of crops. Remarkably, except for the storage organs of crops such as barley, maize and soybean, we know little of the stereoisomeric composition of inositol phosphates in plant tissues. To investigate the metabolic origins of higher inositol phosphates in photosynthetic tissues, we have radiolabel...

Cryptococcus neoformans is the most common cause of fungal meningitis, with high mortality and morbidity. The reason for the frequent occurrence of Cryptococcus infection in the central nervous system (CNS) is poorly understood. The facts that human and animal brains contain abundant inositol and that Cryptococcus has a sophisticated system for the acquisition of inositol from the environment s...

UNLABELLED In the context of deciphering the metabolic strategies of the obligate pathogenic fungi in the genus Pneumocystis, the genomes of three species (P. carinii, P. murina, and P. jirovecii) were compared among themselves and with the free-living, phylogenetically related fission yeast (Schizosaccharomyces pombe). The underrepresentation of amino acid metabolism pathways compared to those...

Since the isolation of myo-inositol from biological sources over a hundred years ago, little has been reported concerning its metabolism. Experiments in nutrition have implicated inositol variously as a vitamin (1) and as a lipotropic agent (2) ; and more recently inositol has been identified as a soluble factor required for the survival of human cells grown in tissue culture (3). The presence ...