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Surface spectrofluorometry of the rabbit urinary bladder
Author(s) -
Levin Robert M.,
Ruggieri Michael R.,
Hypolite Joseph A.,
Malkowicz S. Bruce,
Wein Alan J.
Publication year - 1987
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.1930060208
Subject(s) - oxidative phosphorylation , nad+ kinase , biochemistry , contraction (grammar) , metabolism , fluorescence , chemistry , biophysics , biology , endocrinology , enzyme , physics , quantum mechanics
Proper function of the urinary bladder is dependent on the delivery of a normal supply of blood, oxygen, and nutrients to the tissue. The smooth muscle elements of the bladder utilize metabolic energy in the form of ATP and other high‐energy compounds to support bladder contraction. One of the first metabolic indications of contractile activity would be alterations in the oxidative state (redox) of the tissue, which is reflected by the NADH/ NAD ratio. NADH is a metabolic intermediate synthesized during substrate metabolism and utilized during energy production and utilization. We have studied NADH metabolism in the in vitro bladder strip preparation utilizing a surface spectrofluorometer. This instrument monitors NADH fluorescence in tissue preparations with the use of an optical fiber probe placed on the serosal surface of the strip. The bladder strips displayed rhythmic contractile activity. This was correlated with alterations in NADH fluorescence. There was an excellent correlation (correlation coeficient of 0.986) between the frequency of the spontaneous activity of both contraction and fluorescence. An increase in tension was followed (in seconds) by a decrease in fluorescence. The basal NADH fluorescence was modulated by metabolic inhibitors as would be expected by their metabolic actions: Anoxia and sodium azide (metabolic inhibitors of oxidative phosphorylation) produced a marked increase in the redox state (NADH fluorescence), whereas DNP (a mitochondrial uncoupler) produced a marked decrease. Bethanechol stimulated an increase in tension and a reduction in fluorescence. The above findings suggest that NADH surface spectrofluorometry reflects NADH metabolism in the detrusor smooth muscle and that fluctuations in such spectra correlate well with functional activity. NADH surface spectrofluorometry displays potential as a noninvasive method of monitoring one aspect of detrusor metabolism.