Effects of litter size on sympathetic activity in young adult rats.
Rearing animals in small litters induces a permanent increase in body weight and body fat. To determine whether changes in sympathoadrenal activity contribute to this effect, litter size was adjusted the day after birth and maintained until weaning at 21 days. Sympathetic nervous system (SNS) activity was measured in adult animals using [(3)H]norepinephrine ([(3)H]NE) turnover in peripheral tissues. Although litter size was without effect on [(3)H]NE turnover in chow-fed animals, acceleration of [(3)H]NE turnover by dietary sucrose was completely abolished in heart and attenuated in interscapular brown adipose tissue and kidney of rats reared in small litters. Body and epididymal fat-pad weights were heavier in rats reared in small litters; however, weight gain in response to dietary enrichment with sucrose did not differ as a function of litter size. Thus litter size alters dietary activation of the SNS, and this effect presumably reflects changes in central nervous system regulation.
Young
James B
JB
Department of Medicine, Northwestern University Medical School, Chicago, Illinois 60611, USA. jbyoung@northwestern.edu
D002001:Adipose Tissue, Brown / Q000033:anatomy & histology / Q000502:physiology; D000311:Adrenal Glands / Q000502:physiology; D000367:Age Factors; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D019422:Dietary Sucrose / Q000494:pharmacology; D002149:Energy Intake / Q000502:physiology; D005260:Female; D006321:Heart / Q000033:anatomy & histology; D007668:Kidney / Q000033:anatomy & histology; D008098:Litter Size / Q000502:physiology*; D008297:Male; D009638:Norepinephrine / Q000493:pharmacokinetics; D009929:Organ Size; D051381:Rats; D012469:Salivary Glands / Q000033:anatomy & histology; D013564:Sympathetic Nervous System / Q000502:physiology*; D014316:Tritium; D015430:Weight Gain
D019422:Dietary Sucrose; D014316:Tritium; D009638:Norepinephrine