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Biomedical subjects

C J Lynch

Publications and source records attributed to C J Lynch.

64 records · Page 4Linked to original sources
PubMed1981

Mobilization of a common source of smooth muscle Ca2+ by norepinephrine and methylxanthines.

The ability of norepinephrine (NE), caffeine (CAF), theophylline (THEO), dinitrophenol (DNP), and potassium (high K) to mobilize cellular Ca2+ in rabbit aorta was examined using 45Ca-efflux techniques. After 10 min of Ca2+ deprivation using either Ca-free EGTA or Ca-free lanthanum (La3+) buffers, NE, CAF, and DNP still caused an increase in 45Ca-efflux rate, indicating a cellular source of 45Ca, while high K did not. Contractile behavior after Ca removal paralleled 45Ca-efflux events. CAF (10 mM) inhibited NE contractile responses, and this inhibition was associated with the depletion of the NE-releasable Ca2+ store. Previous exposure to CAF during 45Ca efflux reduced subsequent stimulation of 45Ca efflux was not additive. THEO caused a stimulation of 45Ca efflux similar to CAF. CAF, THEO, and 3-isobutyl-l-methylxanthine caused a two- to threefold increase in cAMP levels in association with their stimulation of 45Ca efflux. These results suggest that NE and methylxanthines mobilize a common cellular Ca2+ source that is associated with contraction in the case of NE but relaxation in the case of methylxanthines.

Animals↗
PubMed1978

Toward less hazardous cigarettes. Current advances.

Critical levels of selected cigarette smoke constituents have been expressed in terms of maximum numbers of pre-1960 cigarettes that a smoker may consume daily without increasing his mortality risk substantially above that of a nonsmoker. This could still imply an important risk, although it may be difficult to detect. We relate these levels to the yields of 27 current low tar and nicotine commercial cigarettes, as measured at the Oak Ridge National Laboratory. In addition, the yields of these selected constituents concomitant with the yield of 1 mg of nicotine are provided as a guide for the smoker who titrates or adjusts his smoking pattern to accommodate a fixed daily intake of nicotine.

Acrolein↗