Clenbuterol, a β2-adrenergic agonist, reciprocally alters PGC-1 alpha and RIP140 and reduces fatty acid and pyruvate oxidation in rat skeletal muscle

Clenbuterol, a β2-adrenergic agonist, reduces mitochondrial content and enzyme activities in skeletal muscle, but the mechanism involved has yet to be identified. We examined whether clenbuterol-induced changes in the muscles' metabolic profile and the intrinsic capacity of mitochondria to oxidize substrates are associated with reductions in the nuclear receptor coactivator PGC-1 alpha and/or an increase in the nuclear corepressor RIP140. In rats, clenbuterol was provided in the drinking water (30 mg/l). In 3 wk, this increased body (8%) and muscle weights (12-17%). In red (R) and white (W) muscles, clenbuterol induced reductions in mitochondrial content (citrate synthase: R, 27%; W, 52%; cytochrome-c oxidase: R, 24%; W, 34%), proteins involved in fatty acid transport (fatty acid translocase/CD36: R, 36%; W, 35%) and oxidation [β-hydroxyacyl CoA dehydrogenase (β-HAD): R, 33%; W, 62%], glucose transport (GLUT4: R, 8%; W, 13%), lactate transport monocarboxylate transporter (MCT1: R, 61%; W, 37%), and pyruvate oxidation (PDHE1α, R, 18%; W, 12%). Concurrently, only red muscle lactate dehydrogenase activity (25%) and MCT4 (31%) were increased. Palmitate oxidation was reduced in subsarcolemmal (SS) (R, 30%; W, 52%) and intermyofibrillar (IMF) mitochondria (R, 17%; W, 44%) along with reductions in β-HAD activity (SS: R, 17%; W, 51%; IMF: R, 20%; W, 57%). Pyruvate oxidation was only reduced in SS mitochondria (R, 20%; W, 28%), but this was not attributable solely to PDHE1α, which was reduced in both SS (R, 21%; W, 20%) and IMF mitochondria (R, 15%; W, 43%). These extensive metabolic changes induced by clenbuterol were associated with reductions in PGC-1α (R, 37%; W, 32%) and increases in RIP140 (R, 23%; W, 21%). This is the first evidence that clenbuterol appears to exert its metabolic effects via simultaneous and reciprocal changes in the nuclear receptor coactivator PGC-1α and the nuclear corepressor RIP140.     

Book reviews

THE BIOLOGY OF MOSSES. by D. H. S. R ichardson
PRINCIPLES OF GENETIC MANIPULATION: AN INTRODUCTION TO GENETIC ENGINEERING . By R. W. O ld & S. B. P rimrose Second Edition
HANDBOOK OF PLANT VIRUS INFECTIONS: COMPARATIVE DIAGNOSIS . Edited by E douard K urstak .
CYTOGENETICS . By J urgen S chulz -S chaeffer
PLANT SCIENCE: AN INTRODUCTION TO WORLD CROPS . By J. J anick , R. W. S chery , F. W. W oods , & V. W. R uttan     

Books

Book reviews in this article:
C ommunication and B ehavior of W hales . R. Payne (ed.).
S trandings : W ays T o S ave W hales . F. D. r obson .
O rders and F amilies of R ecent M ammals of T he W orld . S. Anderson and J. Knox Jones, Jr. (eds.).
S oviet -A merican C ooperative R esearch on M arine M ammals . V olume l—P innipeds . F. H. Fay and G. A. Fedoseev (eds.).
P athobiology of M arine M ammal D iseases . E. B. Howard (ed.).
S eals of T he W orld . (Second Edition.) J. E. Ring. British Museum and Cornell University Press.
T he G ray W hale : E schrichtius R obustus . M. L. Jones, S. L. Swartt and S. Leatherwood.
T he S ierra C lub H andbook of W hales and D olphins . S. Leatherwood and R. R. Reeves.     

Books

Book reviews in this article:
H earingby W halesand D olphins . W. W. L. Au, A. N. Popper and R. R. Fay, eds.     

Books Reviews

Book reviews in this article:
M arine M ammals A shore —A F ield G uide for S trandings .
S tudies of W hite W hales ( D elphinapterus L eucas ) and N arwhals ( M onodon M onoceros ) in G reenland and A djacent Waters. E. W. Born, R. Dietz and R. R. Reeves, eds.
B ooks R eceived
L ife in M oving F luids : The Physical Biology Of Flow. Second Edition.     

Book Reviews

Book reviewed in this article:
Behaviour of Teleost Fishes, 2nd edn. Edited by T.J. P itcher
The IUCN Review of the Southern Okavango Integrated Water Development Project by T. S cudder , R.E. M anley , R.W. C olev , R.K. D avis , J. G reen , G.W. H oward , S.W. L awry , D. M artz , P.P. R ogers , A.R.D. T aylor , S.D. T urner , G.F. W hite and E.P. W right     

Books

Book Reviewed in this article:
A nimal T raining : S uccessful A nimal M anagement T hrough P ositive R inforcement . Ken Ramirez.
C onservation and M anagement of M arine M ammals . J. R. Twiss, Jr., R. R. Reeves and S. Montgomery, eds.
W ebster's W hales and D olphins of the W orld (CD-ROM).     

BOOK REVIEWS

Book reviewed in this article:
THE EUROPEAN FRESHWATER EEL by V. R. P. Sinha & J. W. Jones
TURBULENCE IN LAKES 6 RIVERS by 1. R. Smith.
AN ILLUSTRATED GUIDE TO AQUATIC AND WATER-BORNE HYPHOMYCETES by C. T. Ingold.
KEY TO BRITISH DlXlDAE by R. H. L. Disney
KEY TO BRITISH FRESHWATER CRUSTACEA: MALACOSTRACA by T. Gledhill, D. W. Sutcliffe & W. D. Williams
THE STRUCTURE OF MARINE ECOSYSTEMS by John H. Steele     

New Books

Book reviewed in this article: Vygotsky, L. S. & Luria , A. R. 1993: Studies on the History of Behavior: Ape, Primitive, and Child, edited and translated by V. I. Golod & J. E. Knox. Mitchell , R. W., Thompson , N. S. & Miles , R. W. (eds) 1996: Anthropomorphism, Anecdotes, and Animals. Günther , R. (ed.) 1996: Die Amphibien und Reptilien Deutschlands.     

Wavelength Dependency of Light-Induced Effects on Photoperiodic Clock in the Migratory Blackheaded Bunting (Emberiza melanocephala)

The effects of light wavelength on photoperiodic clock were determined in the migratory male blackheaded bunting (Emberiza melanocephala). We constructed an action spectrum for photoperiodic induction (body fattening, gain in body mass, and gonadal recrudescence) by exposing birds for 4.5 weeks to 13 h light per day (L:D = 13:11 h) of white (control), blue (450 nm), or red (640 nm) color at irradiances ranging from 0.028 to 1.4 W m^?2. The threshold light irradiance for photoinduction was about 10-fold higher for blue, compared to red and white light. Phase-dependent effects of light wavelength on the photoperiodic clock were further examined in the next two sets of skeleton photoperiods (SKPs). In the first set of SKPs, birds were exposed for four weeks to asymmetrical light periods (L:D:L:D = 6:6:1:11 h) at 0.25 ± 0.01 W m^?2; two light periods applied were of the same (450 nm: blue:blue, B:B; 640 nm, red:red, R:R) or different (blue:red, B:R or red:blue, R:B) wavelengths, or of white:white (W:W, controls). Photoperiodic induction occurred under R:R and B:R, but not under B:B and R:B light conditions; the W:W condition induced an intermediate response. The second set of SKPs used symmetrical light periods (L:D:L:D = 1:11:1:11 h), and measured effects also on the activity rhythm. Birds were first exposed to one of the four SKPs (R:R, B:B, R:B, or B:R) for three weeks, subsequently were released into dim constant light (LL_dim; ?0.01 W m^?2, the night light used in an L:D cycle) for two weeks, and then were returned to respective SKPs for another three weeks. Activity was greater in the R:R compared to B:B, and in B:R compared to R:B light condition. Zugunruhe (intense nighttime activity, indicating migratory restlessness in a caged situation) developed under the R:R and B:R, but not the B:B and R:B, light condition. Under LL_dim, all birds free-ran with a period >24 h, the Zugunruhe had a circadian period longer than the daytime activity, and the re-entrainment to SKPs was influenced by the position of light periods relative to circadian phase of the activity rhythm. Photoperiodic induction at the end of 8 weeks was found in the R:R and B:R, but not in B:B, light conditions; in the R:B condition only one bird had initiated testes. Taken together, these results suggest that in the blackheaded bunting, the circadian photoperiodic clock is differentially responsive to light wavelengths; this responsiveness is phase-dependent, and the development of Zugunruhe reflects a true circadian function. Wavelength-dependent response of the photoperiodic clock could be part of an adaptive strategy in evolution of the seasonality in reproduction and migration among photoperiodic species under wild conditions.     

Control of Rhizoctonia solani and Cotton Seedling Disease by Laetisaria arvalis and a Mycophagous Insect Proisotoma minuta (Collembola)

Population changes in Pseudocercosporella herpotrichoides with and without fungicide selection A conidium mixture of W (wheat-type) and R (rye-type) strains of Pseudocercosporella herpotrichoides (W:R = 1:1) was incubated on PD-agar without fungicide or amended with the imidazole prochloraz or the triazole cyproconazole. The W:R ratio was assessed over four generations using the different benomyl sensitivity of the strains as marker. In untreated mixtures, the R strain completely dominated the population already after two generations. Similarly, in cyproconazole-treated mixtures, the R strain increased to 100% after the second generation, whereas in prochloraz-treated mixtures the R strain either followed the same pattern as in untreated mixtures or fluctuated around the initial proportion of 50% over four generations. The W and R strains displayed different fitness properties. The average hyphal growth rate was 8.5 mm/10 d and 4.5 mm/10 d for the W and the R strains, respectively; the sporulation capacity was 80 and 400 conidia/colony, respectively, for the two strains. The different fitness resulted in a strong dominance of the R strains both in vitro and in field populations towards the end of the vegetation period. This shift towards R-dominance occurred about equally fast with or without fungicide selection.     

Books

Book reviews in this article:
S tudies of S ea M ammals in S outh L atitudes . J. K. Ling and M. M. Bryden (eds.).
E xploitation of M arine C ommunities . R. M. May (ed.).
H andbook of M arine M ammals . Volume 3. The Sirenians and Baleen Whales. Sam H. Ridgway and Richard Harrison (eds.).
I nternational R egulation of W haling : F rom C onservation of W haling F rom C onservation of W hales and R egulation of W hale -W atching . Vols. 1 and 2. Patricia Birnie (ed.).
M arine M ammals and F isheries . J. R. Beddington, R. J. H. Beverton and D. M. Lavigne (eds.).
T he E lements of G raphing D ata . William S. Cleveland.     

Books

Book reviews in this article:
H andbook of M arine M ammals . V olume 3: T he S irenians and B aleen W hales . S. H. Ridgway and R. Harrison (eds.).
L es P hoques M oines -M onk S eal . Ronald and R. Duguy (eds.).
T he E lements of G raphing D ata . W. S. Cleveland.
G uia P ara el R econocimiento de C etaceos del M ar A rgentino . A. Lichter and A. Hooper.
M amiferos M arinos de C hile . W. Sielfeld K.
T he W hale W atcher's H andbook . E. Hoyt. Illustrations by P. Folkens.
W hales and D olphins of N ew Z ealand and A ustralia : A n I dentification G uide . A. N. Baker.     

BOOK REVIEW

Book Review in This Article:
Glutamic Acid: Advances in Biochemistry and Physiology (Monographs of the Mario Negri Institute for Pharmacological Research, Editors L. J. F iler , J r ., S. G arattini , M. R. K are , W. A nn R eynolds & R. J. W urtman )
Functional Biochemistry of the Neuroglia by L. Z. P evzner .     

Book reviews

Book reviews in this article: Fauna of Australia. Vol. IB. Mammalia Edited by D. W. Walton and B. J. Richardson. Plant Physiological Ecology: Field Methods and Instrumentation Edited by R. W. Pearcy, J. Ehleringer, H. A. Mooney and P. W. Rundel. Fire in the Tropical Biota: Ecosystem Processes and Global Challenges Edited by J. G. Goldammer. Nature Conservation 2: The Role of Corridors Edited by D. A. Saunders and R. J. Hobbs.     

REVIEWS

O n the N orthwest : C ommercial W haling in the P acific N orthwest 1790–1967. Robert Lloyd Webb.
T he S ei W hale : P opulation B iology , E cology and M anagement . Joseph Horwood
W ildlife R adio T agging , E quipment , F ield T echniques and D ata A nalysis . Robert Hayward.
B iology of the G enus C ephalorhynchus . R. L. Brownell, Jr. and G. P. Donovan, eds.
H andbook of M arine M ammals . V olume 4: R iver D olphins and the L arger T oothed W hales . S. H. Ridgway and R. Harrison, eds.
P olar B ears . Ian Stirling.
T he W hales of H awaii . Kenneth C. Balcomb, III.
W hales , D olphins and P orpoises . Richard Harrison and M. M. Bryden, eds.     

Book Reviews

Zoophysiology. Coordinating Editor: F arner , D. S. Editors: H einrich , B.; H oar , W. S.; J ohansen , K.; L anger , H.; N euweiler , G.; R andall , D. J. Vol. 17: S mith , R. J. F.: The Control of Fish Migration. .
Systematische Zoologie. Begründet von A dolf R emane , V olker S torch und U lrich W elsch . Fortgeführt von Prof. Dr. V olker S torch , Zoologisches Institut der Universität Heidelberg, und Prof. Dr. Dr. U lrich W elsch , Anatomische Anstalt der Universität München.     

Book Reviews

Book Reviewed in this article:
B lakeman J. P. and B. W illiamson (eds.): Ecology of Plant Pathogens .
L aux , W., 49, Deutsdie Pflanzenschotztagung in Heidelberg. 26–29 September 1994 .
The Protistan Cell Surface . W etherbee , R., R. A. A ndersen and J. D. P ickett H eaps (eds.).
Internationales Symposium uber Luckenindikationen .     

Books

Book reviews in this article:
A ntarcitc E cology . R. M. Laws (ed.).
S eals O f T he W orld . J. E. King.
R eproduction I n W hales , D olphins and P orpoises . W. F. Perrin, R. L. Brownell, Jr., and D. P. DeMaster, eds.
E volution I n T he G alapagos I slands . R. J. Berry (ed.).
H istorical W haling R ecords . M. F. Tillman and G. P. Donovan (eds.).
D iving and A sphyxia , A C omparative S tudy O f A nimals and M an . R. Elsner and B. Gooden.     

REVIEWS

Book reviewed in this article:
G eneral F eatures of the P aleobiological E volution of C etacea , Guram Andreevich Mchedlidze.
How TO WRITE and PUBLISH A SCIENTIFIC PAPER. R. A. Day.
R eproduction in W hales , D olphins , and P orpoises . W. F. Perrin, R. L. Brownell, Jr., and D. P. DeMaster (Eds.).
C ommunication and B ehavior of W hales . R. Payne (Ed.).
E cholocation in W hales and D olphins . P. E. Purves and G. E. Pilleri.