Apparent lack of beta 3-adrenoceptors and of insulin regulation of glucose transport in brown adipose tissue of guinea pigs.

Norepinephrine-induced thermogenesis was substantial in adipocytes from brown adipose tissue (BAT) of cold-acclimated guinea pigs but absent in adipocytes from BAT of warm-acclimated guinea pigs. There was no thermogenic response to any beta 3-adrenergic agonist (CL-316,243, ZD-7114, BRL-28410, CGP-12177). The receptor was characterized as a beta 1-adrenoceptor.

Optimized radiolabelling of pig granulocytes with indium-111 tropolonate.

Standard labelling methods using 111In-tropolonate in plasma resulted in lower labelling efficiency (LE) with pig granulocytes than with human cells. Addition of acid-citrate-dextrose (ACD) to cell-free plasma in a ratio of 1:10 tripled the LE to a value which was not significantly different from that obtained in saline. Under optimized conditions, LE was 67 +/- 2% (mean +/- SE) with pig granulocytes, which remained lower than that obtained with human cells but was adequate for nuclear imaging studies of granulocyte deposition in the pig.

Colchicine lesions of ventromedial hypothalamus: effects on regulatory thermogenesis in the rat.

Experiments were carried out to test whether the ventromedial hypothalamus (VMH) is the site of a pathway that stimulates thermoregulatory heat production in brown adipose tissue (BAT). Adult Sprague-Dawley rats received bilateral 50 nl microinjections of colchicine solution into the VMH (0.1, 0.

Absence of increased oxygen consumption in brown adipose tissue of rats exhibiting "cafeteria" diet-induced thermogenesis.

Young male Sprague-Dawley rats were induced to overeat (approximately 45%) by provision of a "cafeteria" (CAF) diet of palatable human foods. Normophagic rats fed a commercial chow or a semisynthetic diet served as controls. The CAF rats exhibited (a) the reduced food efficiency and the propranolol-inhibitable elevation in resting metabolic rate (resting VO2) that are indicative of a facultative diet-induced thermogenesis (DIT) by which excess energy gain is resisted, and (b) certain changes in brown adipose tissue (BAT) that are among those taken as evidence for BAT as the effector of DIT, e.

Defective trophic response of brown adipose tissue of myopathic hamsters.

Hamsters with muscular dystrophy (BIO 14.6) have a smaller than normal amount of brown adipose tissue. Two stimuli that promote growth of brown adipose tissue in normal hamsters, short photoperiod and eating a high-fat diet, are here shown to be without effect on brown adipose tissue of myopathic hamsters.