Meeting Abstract

86.3  Friday, Jan. 7  Does high level of Basal Metabolic Rate increase susceptibility to food shortage? BRZEK, Pawel*; KSIAZEK, Aneta; GEBCZYNSKI, Andrzej; FRANCZUK, Justyna; KONARZEWSKI, Marek; Univ. of Bialystok, Poland; Univ. of Bialystok, Poland; Univ. of Bialystok, Poland; Univ. of Bialystok, Poland; Univ. of Bialystok, Poland brzek@uwb.edu.pl

Energy demands conferred by high BMR may represent significant ecological cost, particularly when food is scarce. Indeed, several studies reported positive link between environmental productivity and BMR on inter- and intra-specific level. Here, we report the results of experiment in which laboratory mice from lines artificially selected towards high (H-BMR) or low (L-BMR) BMR were subjected to 8 wk dietary restriction (DR; 70% of normal food intake). Although higher food intake in H-BMR mice is associated with larger energetically costly internal organs (small intestine, liver, heart and kidneys) and higher spontaneous locomotor activity, DR affected those traits similarly in both lines. However, DR reduced food digestibility significantly more in L-BMR mice. DR also decreased thermogenic capacity (quantified as maximum Helox-induced metabolic rate) significantly more in H-BMR than L-BMR mice. We conclude that large (>40%) intra-specific variation in BMR does not result in higher relative susceptibility to food shortage in H-BMR line, whereas larger gastrointestinal tract in those mice may enable them to cope better with food shortages.