Carbohydrates, principally glycogen, trehalose, and glucose, are the energy reserves for the flight of flies. Glycogen deposits are found in the soluble cytoplasm of the muscle, and the initial reactions of glycogen, trehalose, or glucose catabolism are localized in the cytoplasm (1). During glycolysis, the first oxidative step occurs at the triose level and reduced coenzyme, reduced diphosphop...

1. The kinetics of inhibition of calf-intestinal alkaline phosphatase by inorganic phosphate, fluorophosphate, inorganic pyrophosphate, beta-glycerophosphate and adenosine 5'-triphosphate in the range pH8-10 were investigated. The reference substrate was 4-methylumbelliferyl phosphate. 2. The inhibitions were ;mixed' in that both K(m) and V were affected, but the competitive element was by far ...

The role of mitochondria in the desensitization of insulin secretion was investigated. In rat pancreatic beta cells, both insulin secretion and mitochondrial [Ca2+] increases were desensitized following two challenges with the mitochondrial substrate methyl succinate. In the beta cell line INS-1, similar results were observed when a 5-min interval separated two 5-min pulses. In contrast, ATP ge...

mitochondrial space was not completely reduced. This indicates some mitochondrial oxidative activity when alveolar Po, was in the 0.5-1.0 mrn Hg range. These studies have demonstrated substrate oxidation and respiratory control with isolated lung mitochondria. Measurements of surface fluorescence and tissue redox couples show intracellular reduction of pyridine nucleotides in response to oxidat...

The tendon/ligament-to-bone interface has a complex organization to enable transfer of forces through the tendon/ligament to the bone. The purpose of this study is to create a co-culture environment enabling a tissue-specific tendon region and tissue-specific bone region on a degradable scaffold, using NIH 3T3 fibroblast-deposited extracellular matrix and MC 3T3 osteoblast-deposited extracellul...

Changes of enzymes involved in the hepatic metabolism of long-chain fatty acids (palmitoyl-CoA synthetase (EC 6.2.1.3), carnitine palmitoyltransferase (EC 6.2.1.3), glycerophosphate acyltransferase (EC 2.3.1.15)) in the liver of male rats were examined after ethionine exposure. Ethionine administration resulted in a dose- and time-dependent enhancement of the palmitoyl-CoA synthetase activity b...

In the pancreatic beta-cell, insulin secretion is stimulated by glucose metabolism resulting in membrane potential-dependent elevation of cytosolic Ca2+ ([Ca2+]c). This cascade involves the mitochondrial membrane potential (delta psi[m]) hyperpolarization and elevation of mitochondrial Ca2+ ([Ca2+]m) which activates the Ca(2+)-sensitive NADH-generating dehydrogenases. Metabolism-secretion coupl...

The genetic form of muscular dystrophy in the chicken is by now a well recognized entity (1, 2), and is a condition of some importance, since in many features it approximates the corresponding disease in the human. We have elsewhere reported our preliminary findings with lactic dehydrogenases in dystrophic chickens (3). Further investigations have centered on analysis of the content of the lact...

Reconstruction of tendon and ligament tissues requires proper attachment of the tissue-engineered construct to surrounding tissues. A problem of reconstructing collagen-rich tissues is that an in vitro engineered collagenous network containing fibroblasts will contract and detach from a solid surface. In vivo anchorage of soft connective tissues to mineralized tissues like bones and teeth is ac...

Dynamic changes in lens organophosphate metabolites during 24 hr incubation in 30 mM galactose media were measured with phosphorus-31 nuclear magnetic resonance spectroscopy. The following phosphates were quantitated from the intact crystalline lens: adenosine triphosphate (ATP), adenosine diphosphate (ADP), inorganic orthophosphate, alpha-glycerophosphate, phosphorylated hexoses and trioses, n...