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Caloric restriction prevents age‐related decline in skeletal muscle dihydropyridine receptor and ryanodine receptor expression
Author(s) -
Renganathan M.,
Delbono O.
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01009-6
Subject(s) - ryr1 , ryanodine receptor , medicine , endocrinology , skeletal muscle , caloric theory , dihydropyridine , chemistry , receptor , contraction (grammar) , calcium , voltage dependent calcium channel , biology
The dihydropyridine receptor (DHPR), a voltage‐gated L‐type Ca 2+ channel, and the Ca 2+ release channel/ryanodine receptor isoform‐1 (RyR1) are key molecules involved in skeletal muscle excitation‐contraction coupling. We have reported age‐related decreases in the level of DHPR expression in fast‐ and slow‐twitch muscles from Fisher 344 cross Brown Norway (F344BNX) rats (Renganathan, Messi and Delbono, J. Membr. Biol. 157 (1997) 247–253). Based on these studies we postulate that excitation‐contraction uncoupling is a basic mechanism for the decline in muscle force with aging (Delbono, Renganathan and Messi, Muscle Nerve Suppl. 5 (1997) S88–92). In the present study, we extended our studies to older ages and we intended to prevent or retard excitation‐contraction uncoupling by restricting the caloric intake of the F344BNX rats from 16 weeks of age. Three age groups, 8‐, 18‐, and 33‐month old caloric restricted rats, were compared with ad libitum fed animals. The number of DHPR and RyR1 and DHPR/RyR1 ratio (an index of the level of receptors uncoupling) in skeletal muscles of 8‐month and 18‐month rats was not significantly different in either ad libitum fed or caloric restricted rats. However, the age‐related decrease in the number of DHPR, RyR1 and DHPR/RyR1 ratio observed in 33‐month old ad libitum fed rats was absent in 33‐month old caloric restricted rats. These results suggest that caloric restriction prevents age‐related decreases in the number of DHPR, RyR1 and DHPR/RyR1 ratio observed in fast‐ and slow‐twitch rat skeletal muscles.