The investigations are aimed at assessing and defining the significance of the accelerated cyclic nucleotide metabolic flux that occurs without changes in cell cGMP or cAMP levels in association with the action of excitatory cell stimuli. This model of cyclic nucleotide involvement which contrasts with their influence mediated through changes in their cellular concentration is suggested from investigations of phototransduction and from more recent studies on contraction in smooth muscle to represent a biochemical process in excitation related to intracellular Ca2+ release. This involvement of cyclic nucleotides will be assessed with regard to excitation/contraction coupling in smooth and skeletal muscle and excitation/secretion coupling in parotid gland and platelets. The newly devised technology of monitoring cyclic nucleotide and 5' nucleotide metabolism in intact cells by the rate of incorporation of oxygen 18 from [oxygen 18] water into the Alpha-, Beta- and Gamma-phosphoryls of guanine and adenine nucleotides will be employed to assess the relationship of cyclic nucleotide metabolism to cell excitation and obtain information regarding: 1) the exclusivity of the phophodiesterase pathway in labeling cellular adenine and guanine nucleotide Alpha-phosphoryls; 2) identification of the cellular metabolic pathway that appears to derive from cAMP hydrolysis leading to rapid oxygen 18 labeling of IMP with stimulated contraction; 3) cellular high energy phosphate metabolism and Pi transport associated with excitatory and adaptive cell stimulation; 4) definition of the cellular metabolic compartments of cyclic nucleotides and 5' nucleotides affected by excitatory and adaptive stimulation; 5) relationship of intensity, frequency and duration of excitatory stimulation to cellular cGMP and cAMP metabolic flux; and 6) relationship of excitation-induced acceleration of cyclic nucleotide metabolic flux to intracellular Ca2+ release. These correlative studies will be supplemented by experiments to obtain information regarding; 7) the kinetic and regulatory characteristics of phosphodiesterases and nucleotidyl cyclases associated with cell structures in muscle with Ca2+ uptake and release capability; and 8) the relationship of cyclic nucleotide hydrolysis to the release of Ca2+ from isolated muscle triads.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Physiological Chemistry Study Section (PC)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Minnesota Twin Cities
Schools of Medicine
United States
Zip Code
Dzeja, P P; Zeleznikar, R J; Goldberg, N D (1998) Adenylate kinase: kinetic behavior in intact cells indicates it is integral to multiple cellular processes. Mol Cell Biochem 184:169-82
Dzeja, P P; Zeleznikar, R J; Goldberg, N D (1996) Suppression of creatine kinase-catalyzed phosphotransfer results in increased phosphoryl transfer by adenylate kinase in intact skeletal muscle. J Biol Chem 271:12847-51
Zeleznikar, R J; Dzeja, P P; Goldberg, N D (1995) Adenylate kinase-catalyzed phosphoryl transfer couples ATP utilization with its generation by glycolysis in intact muscle. J Biol Chem 270:7311-9
Zeleznikar, R J; Goldberg, N D (1991) Kinetics and compartmentation of energy metabolism in intact skeletal muscle determined from 18O labeling of metabolite phosphoryls. J Biol Chem 266:15110-9
Angelastro, J M; Purich, D L (1990) Apparently irreversible GTP hydrolysis attends tubulin self-assembly. Eur J Biochem 191:507-11
Zeleznikar, R J; Heyman, R A; Graeff, R M et al. (1990) Evidence for compartmentalized adenylate kinase catalysis serving a high energy phosphoryl transfer function in rat skeletal muscle. J Biol Chem 265:300-11
Yuen, P S; Graeff, R M; Walseth, T F et al. (1989) Non-identity of cGMP as the guanine nucleotide stimulated to bind to ROS by light and ATP. Exp Eye Res 49:75-85
Dawis, S M; Walseth, T F; Deeg, M A et al. (1989) Adenosine triphosphate utilization rates and metabolic pool sizes in intact cells measured by transfer of 18O from water. Biophys J 55:79-99
Deeg, M A; Graeff, R M; Walseth, T F et al. (1988) A Ca2+-linked increase in coupled cAMP synthesis and hydrolysis is an early event in cholinergic and beta-adrenergic stimulation of parotid secretion. Proc Natl Acad Sci U S A 85:7867-71
Dawis, S M; Graeff, R M; Heyman, R A et al. (1988) Regulation of cyclic GMP metabolism in toad photoreceptors. Definition of the metabolic events subserving photoexcited and attenuated states. J Biol Chem 263:8771-85

Showing the most recent 10 out of 15 publications