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Biomedical subjects

B J Moore

Publications and source records attributed to B J Moore.

At least 55 records · Page 3Linked to original sources
PubMed1986

Hyperprolactinemia stimulates food intake in the female rat.

Lactation in the rat is marked by extreme hyperphagia. The present study examined the possibility that elevated prolactin levels contribute to this increase. It also evaluated the effects of hyperprolactinemia on brown adipose tissue and carcass composition. Virgin Osborne-Mendel rats were made hyperprolactinemic via ectopic pituitary transplants (PIT, n = 9) or were sham-operated (SHAM, n = 8). Eight lactating rats (LACT) served as additional controls. Food intake, body weight and rectal temperature were recorded daily. Eleven days postsurgery (or 11-12 days postpartum), the rats were sacrificed, and brown fat (scapular, axillary, cervical and thoracic) was excised, weighed, and assayed for GDP binding, one indicator of thermogenic capacity. Carcasses were subjected to body composition analysis. Although prior to surgery, PIT and SHAM rats weighed the same, PIT rats gained significantly more weight during the experiment than did SHAMs. Percent body fat and food intake (both total intake and intake relative to metabolic body size) were significantly elevated in the PIT rats. GDP binding in both PIT and LACT rats was significantly less than in SHAMs. This was true whether GDP binding was expressed per mg mitochondrial protein or per total amount of mitochondrial protein recovered. These data confirm that brown fat thermogenic capacity is suppressed during lactation. They also demonstrate that elevations of serum prolactin, to levels that are well within physiological limits, are capable of stimulating food intake and white fat deposition in the female rat. It is presently unclear whether these results are a direct or an indirect effect of hyperprolactinemia.

Adipose Tissue, Brown↗
PubMed1986

Metabolism at thermoneutrality and in the cold is reduced in the neonatal preobese Zucker fatty (fa/fa) rat.

Minimum and maximum rates of oxygen consumption (VO2) were determined in 2-, 6- and 8-d-old lean (Fa/?) and preobese (fa/fa or "fatty") Zucker rats. On each study day, three or four naive littermate male pups were placed in individual respiration chambers submerged in a water bath and studied simultaneously over a range of ambient temperatures (24-35 degrees C). The purpose of the cold exposure was to elicit maximal oxygen consumption and to determine the ability of the rat to maintain body temperature during cold stress. Minimum rates of oxygen consumption were observed at 33-34 degrees C in both groups. As ambient temperature was reduced, VO2 increased and rectal temperature decreased. Regression analysis revealed a significantly reduced oxygen consumption in the preobese pups within the thermoneutral zone and during cold exposure. A defect in energy expenditure for heat production was evident in the preobese (fa/fa) pups as indicated by their attenuated cold-induced rate of oxygen consumption and decreased ability to maintain body temperature during cold stress relative to their lean (Fa/?) littermates. Their lower VO2 within the thermoneutral zone implies that the preobese (fa/fa) pups have a decreased metabolic rate even under conditions in which cold-induced thermogenic mechanisms are turned off.

Adipose Tissue, Brown↗
PubMed1986

Automated cognitive assessment of elderly patients: a comparison of two types of response device.

Groups of 14 cognitively impaired elderly people were tested on two automated cognitive tests on several occasions. Patients registered their responses using either a touch-sensitive screen or a board with illuminated response buttons. The results indicate that the touch-sensitive screen is probably a more suitable response device than the button-board. Suggestions that it would prove disadvantageous to elderly patients were not supported, and its continued use is recommended.

Aged↗
PubMed1986

Brown fat mediates increased energy expenditure of cold-exposed overfed neonatal rats.

Genetically lean rat pups, overfed by being raised in small litters of three from day 1 postpartum, rapidly become obese compared with pups raised in standard sized litters of eight. Because of the rapid onset of their obesity, we expected that overfed pups would exhibit defective brown fat thermogenesis as is seen in neonatal genetically obese rodents. O2 consumption (VO2) was measured in 2-, 4-, 6-, and 8-day-old homozygous lean (Fa/Fa) Zucker pups from each treatment. We determined minimum rate of VO2 at thermoneutrality and maximum VO2 in response to progressively colder ambient temperatures. Overfed pups were fatter than standard-fed pups (P less than 0.001). But contrary to our prediction, overfed pups had a significantly increased maximum VO2 in response to acute cold exposure. To test the hypothesis that brown fat mediated the increased VO2 in the overfed pups, scapular brown fat lipectomies were performed on a new group of overfed pups at 2 days of age and compared with sham-operated littermate controls. On day 8, no differences in minimum VO2 were seen at thermoneutrality when brown fat is turned off. But maximum VO2 in response to cold, when brown fat is turned on maximally, was significantly reduced in the lipectomized overfed pups compared with sham-operated overfed littermates. These data suggest that manipulations of diet, accomplished by raising pups in small litters, can increase brown fat thermogenic function. The results of the lipectomy experiment imply that brown adipose tissue is a primary mediator of the increased energy expenditure in response to acute cold exposure in the overfed pups.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1986

Decreased testosterone levels do not mediate short-photoperiod-induced brown fat changes.

Previous studies showed that short photoperiod increased brown fat (BAT) mass and reduced gonadal size and gonadal hormone secretion in hamsters. The present study investigated the possibility that the effects on BAT were dependent on reduced levels of gonadal hormones. BAT from male Syrian hamsters exposed to short photoperiod for 10 wk was significantly greater in mass, protein content, and total maximal citrate synthase and beta-hydroxyacyl-CoA dehydrogenase activities than was BAT from long-photoperiod hamsters, These differences between short- and long-photoperiod exposure were observed in hamsters housed at 21 as well as at 8 degrees C. Short photoperiod also increased the total recovered mitochondrial GDP binding, a finding consistent with increased BAT thermogenic capacity. These short-photoperiod effects were neither mimicked by castration of long-photoperiod hamsters nor prevented by high levels of testosterone administered to short-photoperiod animals. Castration did attenuate the effects of short photoperiod on BAT growth if, after surgery and prior to short-photoperiod exposure, the animals were housed at a long photoperiod for 2-3 wk. In contrast, in hamsters immediately placed at short photoperiod after surgery, castration did not inhibit short-photoperiod effects. The present three experiments demonstrate that, in addition to increasing BAT mass, short photoperiod elevates the thermogenic capacity of BAT, and this elevation does not require the absence or a much reduced testosterone level.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1985

Brown fat thermogenesis and its role in the development of obesity.

The role of brown fat thermogenesis in the development of obesity is considered from a number of perspectives. In adult rats, the impact of scapular brown fat lipectomy on carcass fat accretion was examined in three different rodent models: the Zucker lean (Fa/-) rat which is relatively resistant to obesity, the Zucker obese (fa/fa) rat which is characterized by a particularly severe form of hyperplastic obesity and the Osborne Mendel rat which remains lean on a standard pelleted diet but readily becomes obese on a palatable high fat diet. The consequences of brown fat lipectomy varied from no effect on carcass white fat accretion in Zucker Fa/- lean rats to a significant increase in adiposity in the Zucker fatty fa/fa relative to their respective sham-operated controls. The effect of the Osborne Mendel rat was intermediate between the Fa/- and the fa/fa. The results point to the importance of genetic background with respect to the impact of brown fat lipectomy on the development of white fat adiposity. In the developing Zucker rat at 2 and 8 days of age, in vivo evidence is presented to support the concept that brown fat thermogenesis is attenuated in the fatty fa/fa preobese pup. In animals of the fatty fa/fa genotype, maximum oxygen consumption in response to acute cold exposure was lower than in lean pups of the Fa/Fa genotype. Moreover, at 8 days of age, the rectal temperature of the cold-exposed fa/fa pups fell more precipitously than did that of the lean during the period of cold exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue, Brown↗
PubMed1985

Brown adipose tissue lipectomy leads to increased fat deposition in Osborne-Mendel rats.

Inter- and subscapular brown adipose tissue depots were removed from nine female Osborne-Mendel rats. These lipectomized animals and nine sham-operated controls recovered from surgery for 7 days at 25 degrees C and were then placed on a highly palatable liquid diet. All animals were maintained for a 2nd wk at 25 degrees C before being switched to 8 degrees C. After 9 wk in the cold, animals were killed, and the brown adipose tissue was dissected from scapular, cervical, thoracic, perirenal, and axillary regions. Total brown fat pad mass, protein content, brown adipocyte number, citrate synthase activity, and beta-hydroxyacyl CoA dehydrogenase activity in each of the dissected brown fat depots were significantly less than those of the sham-operated controls. Thus there was incomplete metabolic compensation in the remaining brown fat depots after the removal of the scapular brown fat in the lipectomized rats. The mass and lipid content of the retroperitoneal white adipose depot were significantly increased in the lipectomized rats as was their carcass fat content (up 14%). Food intake of the lipectomized rats was slightly but significantly decreased. These data indicate that a reduction in the amount of functional brown fat is accompanied by increased body fat accretion and are thus consistent with the hypothesis that decreased brown adipose thermogenesis can lead to altered energy balance and increased white fat deposition.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1985

Energy expenditure is reduced in preobese 2-day Zucker fa/fa rats.

The rate of oxygen consumption was measured in 2-day Zucker preobese (fa/fa), homozygous (Fa/Fa) lean, and lean rats of unknown genotype (Fa/?) over the ambient temperature range of 26-35 degrees C. Significant differences in body mass were found among the three groups at this early age, the preobese pups having the greatest body mass. To account for body mass differences, the oxygen consumption data were expressed in terms of metabolic body size (ml O2 consumed X g body mass-2/3 X h-1). This mass-independent rate of oxygen consumption was significantly lower in the preobese pups than in the homozygous lean (Fa/Fa) pups at both thermoneutral (33-34 degrees C) and cold (26-27 degrees C) ambient temperatures at which, respectively, minimal and maximal rates of oxygen consumption were observed. This reduction in energy expenditure occurs before the establishment of hyperphagia or decreased levels of activity in the preobese pups. These data support the view that attenuated energy expenditure is a significant contributor to the early development of obesity in the Zucker fatty rat and point to the possibility of defective brown adipose tissue-mediated thermogenesis in the preobese pup.

Adipose Tissue, Brown↗
PubMed1985

The effect of brown fat removal on the development of obesity in Zucker and Osborne-Mendel rats.

Removal of significant amounts of brown fat in young Zucker rats maintained at room temperature triggered compensatory changes in the remaining brown fat depots. These changes, which occurred to a greater extent in the lean than in the obese rats, enhanced the thermogenic potential of the remaining depots, thus possibly accounting for the lack of increased adiposity in these lipectomized rats. When the Zucker rats were maintained in the cold, rather than at room temperature, their ability to compensate for removal of the scapular brown fat was compromised, particularly in the obese animals. Under such conditions, the amount of functional brown fat was significantly reduced, and the amount of body fat elevated. In the lipectomized Zucker rats, this increase in adiposity was accompanied by increased body mass. In contrast, in the cold-exposed Osborne-Mendel rats, where lipectomy was not accompanied by compensatory increases in the mass and cellularity of the remaining brown fat depots, increased body fat occurred in the absence of any increase in food intake or in total body mass.

Adipose Tissue, Brown↗
PubMed1984

One cycle of reproduction consisting of pregnancy, lactation or no lactation, and recovery: effects on carcass composition in ad libitum-fed and food-restricted rats.

Groups of nine ad libitum-fed and food-restricted Osborne-Mendel rats weighing between 200 and 220 g at mating were killed on day 21 of pregnancy, day 21 of lactation and day 21 of the postweaning recovery period. Restricted rats were fed 70% of the mean daily ad libitum intake. Groups of nine ad libitum-fed animals, not permitted to suckle their young, were killed on day 21 postpartum and day 21 of the recovery period. Groups of nine nonpregnant rats of comparable initial body weight were killed at appropriate times to serve as advancing age and growth controls. Changes in carcass composition were determined in each group at the end of the pregnancy, lactation and recovery periods. Carcass fat was elevated in the nonlactating group on day 21 postpartum compared to lactating animals and nonpregnant controls. At the end of the study, carcass weight was highest in the ad libitum-fed lactating group. This was due to increased carcass water and not to increased carcass fat. In fact, carcass fat was significantly reduced in the ad libitum-fed lactating group compared to nonpregnant controls. During the recovery period, the absolute increase in carcass fat was greater in the restricted group than in the ad libitum-fed group. The data indicate that 1) pregnancy followed by no lactation results in an increase in carcass fat content and 2) the postweaning recovery period is marked by a tendency to increase carcass fat even in food-restricted rats.

Animals↗
PubMed1984

One cycle of reproduction consisting of pregnancy, lactation or no lactation, and recovery: effects on fat pad cellularity in ad libitum-fed and food-restricted rats.

Groups of nine ad libitum-fed and food-restricted Osborne-Mendel rats, weighing between 200 and 220 g at mating, were killed on day 21 of pregnancy, day 21 of lactation and day 21 of a postweaning recovery period. Food-restricted rats were fed 70% of the mean daily ad libitum intake. Groups of nine ad libitum-fed animals, not permitted to suckle their young, were also killed on day 21 and day 42 postpartum. Groups of nine nonpregnant rats of comparable body weight on day 0 were killed on day 0, day 21, day 43 and day 64 of the experiment to serve as age and growth controls. At the time of death, subscapular, parametrial and retroperitoneal fat pads were dissected, weighed and sampled for determination of fat cell size and fat cell number. At 21 days postpartum, animals that had gone through pregnancy but did not lactate exhibited increased fat pad weight and significantly increased fat cell number in the parametrial and retroperitoneal depots although not in the subscapular depot. This increase in fat cell number was still evident 42 days postpartum and may predispose these animals to subsequent obesity.

Adipose Tissue↗
PubMed1984

The effects of high fat feeding during one cycle of reproduction consisting of pregnancy, lactation and recovery on body composition and fat pad cellularity in the rat.

The changes in adipose depot weight, cell size, cell number and body composition during pregnancy, lactation and recovery were studied in Osborne-Mendel rats fed standard or high fat diets. Rats were killed on day 21 of pregnancy, after 21 days of lactation, and after 21 or 22 days of a postlactational recovery period. Nonpregnant control groups were killed at the beginning and at the conclusion of the experimental period. The high fat-fed, mated group was always fatter than similarly treated animals fed standard diets throughout pregnancy and lactation. However, by the end of the recovery period, carcass composition of the animals fed high fat or standard diets and the nonpregnant groups were not statistically different. The weight of the parametrial, retroperitoneal and subscapular depots was higher in the high fat-fed animals at the end of the recovery period, and in the latter two pads, this increase was statistically significant. Thus, despite the extensive lipid mobilization that occurs during lactation, the high fat-fed animals appear to be predisposed to postpartum obesity.

Adipose Tissue↗
PubMed1981

Measuring effectiveness of service aides in infant immunization surveillance program in North Central Texas.

The Immunization Division of Texas Public Health Region 5 sought to measure the per cent of referrals taking immunization action as a result of service aide contact. From data collected on newborn-nonresponders during a 12-month period, results show that aides may be credited with influencing 44 percent of the referrals reporting subsequent immunization.

Community Health Workers↗
PubMed1980

Effect of short term benzene administration on circulating lymphocyte subpopulations in the rabbit: evidence of a selective B-lymphocyte sensitivity.

Repeated subcutaneous administration of benzene to rabbits (0.25 or 0.5 ml/kg/day) produced a progressive lymphocytopenia with a 80% reduction in total circulating lymphocytes after 10 days of treatment. This decrease in circulating lymphocytes was due primarily to a reduction in B- cells with 17-30% remaining after 10 days of treatment, depending on the dose. Immunoglobin surface receptor - negative cells, presumably T lymphocytes, were relatively unaffected until late in the experiment at the high dose. It is concluded that benzene has a relatively selective cytotoxic effect on circulating B-lymphocytes in the rabbit.

Animals↗