ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720270

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The amplitude of the electrical activity of the ventromedial hypothalamic nucleus (VMH) and lateral hypothalamic area (LH) was evaluated in rats after 24-hr food deprivation to determine the effects of the diet they had received before fasting. Bioelectrical potentials were registered by means of monopolar electrodes. In rats after 24-hr food deprivation an increase in the absolute values of the amplitude of the electrical activity of the VMH and LH was found; this effect was more pronounced in the LH. Comparing the amplitude of the electrical activity of the VMH and LH, we found it to be always higher in the VMH in ad libitum fed rats, while in 24-hr food-deprived rats the electrical activity was always higher in the LH. The extent of changes depended on the diet the rats had received before fasting--they were most marked in rats fed on a high-protein diet and less marked in rats fed on either a standard or a high-fat diet before food deprivation.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720271

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Weanling genetically obese (C57BL/6J-ob/ob) and lean (+/?) mice were given access to either a standard laboratory diet or the standard diet plus a 32% sucrose solution. At the end of a 4-week period, animals were sacrificed and opiate receptor binding determined. Both obese and lean mice given access to sucrose consumed approximately 30% more calories per day than animals given access to the standard diet alone. Obese animals consumed significantly more calories from the sucrose solution than the lean animals. Genetically obese animals weighed more than lean littermates throughout the course of the study. Differences in body weight due to sucrose supplementation in both genetically obese and lean mice were significant by day 10 and increased in magnitude until the termination of the study. Whereas there were no significant differences in specific opiate receptor binding (pmol 3H-naloxone bound/mg brain protein) between the genetically obese and lean animals, opiate receptor binding was significantly greater in genetically obese animals given access to sucrose than in obese animals which had access only to the standard diet. These data demonstrate that the sucrose-induced model of obesity functions in mice and that giving ob/ob mice access to sucrose in addition to a standard laboratory diet results in increased opiate receptor binding.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720272

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Twenty-one grossly obese patients were studied before and repeatedly after gastroplasty. Eighteen months after surgery, three groups of patients were identified which had similar preoperative weights but showed significantly different patterns of weight loss. About one third of the patients were considered unsuccessful (less than 20% weight loss). Psychological assessment, using the meta-contrast technique, showed that signs of regressive defense and of immature identity decreased postoperatively. Mild to moderate depressive reactions were found in two thirds of the patients postoperatively and were significantly more frequent among the successful patients. Acute depressive episodes, severe enough to require professional intervention, occurred in four patients, three of whom belonged to the successful group. No correlation could be found between surgical complications or metabolic alterations after gastroplasty and postoperative depression, implying that these factors do not primarily influence the patient's postoperative psychological status. Rather, we suggest that the marked weight loss as such leads to problems of adaptation which in turn may trigger depressive reactions.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720273

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The circadian variation in protein content in the digestive tract was studied in parallel with food intake in the free-feeding rat maintained under a 12:12 hr light:dark cycle (lights on at 07 hr). Rate of ingestion of a casein-based diet increased progressively during daytime, but most of the intake occurred in the dark. Gastric emptying of proteins lagged by a 3-hr interval behind intake. N content in the intestine divided equally into three segments also increased in the dark. The rise was specific for each segment with the most marked rise in the second segment. Endogenous N levels were high and accounted for at least two thirds of intestinal N levels. There was no net absorption of N in the first intestinal segment due to dilution by endogenous proteins. Absorption was at an average of 70% in the second segment and reached 85% in the distal intestine. The amino acid composition of intestinal protein content reflected endogenous proteins much more than casein. Specific trypsin activity increased distally. The appearance of nitrogenous material (alpha-amino N) in portal blood also followed a circadian variation reflecting the pattern of food intake. In spite of their high level in the intestine, endogenous proteins did not lead to an appreciable appearance of nitrogenous material in the blood except at 10 hours. Results indicate that fluctuation in food intake is accompanied by complex variations in protein contents of the digestive tract. Endogenous protein levels were high and seemed to have a slow turnover.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720274

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Adult rats were submitted to a 4-day starvation period or maintained on a 50% carbohydrate-restricted diet for 8 consecutive days to obtain a body weight loss of 20-30%. Serum dopamine-beta-hydroxylase (DBH) activity and amino acids content were measured as well as brain tryptophan and tyrosine levels. Moreover, brain serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), noradrenaline (NA), and dopamine (DA) contents were assayed in five brain areas. In 4-day starved and 8-day carbohydrate-restricted rats, the serum tyrosine and total tryptophan contents as well as tyrosine to the sum of six neutral amino acids ratios were lowered. Moreover, in these groups, free tryptophan to the sum of six neutral amino acids ratio remained normal and serum DBH activity increased. In the brain, to a decreased tyrosine content observed in 4-day starved and 8-day carbohydrate-restricted rats corresponded a high DA to NA ratio in the hypothalamus, thalamus, and raphe nuclei, thus suggesting a low DA utilization whereas a low DA to NA ratio was found in the neostriatum. On the other hand, brain tryptophan content was decreased in 4-day starved rats and increased in 8-day carbohydrate-restricted rats. In the former group, a high 5-HT to 5-HIAA ratio characteristic of a low 5-HT utilization was found in the hypothalamus and neostriatum whereas in the latter group a significant decrease in this ratio was only observed in the thalamus. These results suggest that the biochemical response to starvation vs carbohydrate restriction can be differentiated on neurochemical and neuroanatomical bases.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720275

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

Rats shifted from a 40% sucrose solution to a quinine-adulterated (30 mg/100 ml) 40% sucrose solution showed a reduction in consumption to a level considerably below that of animals exposed to only the quinine-adulterated solution. The animals tended to recover from this negative contrast effect over a 5-day postshift period and, in general, the degree of contrast was about equivalent to that of animals shifted from a 32% to a 4% sucrose solution. There were no sex differences in the rats shifted from 32% to 4% sucrose, but female rats shifted to the quinine-adulterated sucrose showed larger contrast effects than male rats exposed to the same shift.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720276

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The role of dietary protein intake in the pathogenesis of progressive renal disease has been recently reexamined. Studies of both animal and humans with chronic renal disease have shown that restriction of dietary protein may slow the progression of the decline in renal function. This occurs because of a decrease in intraglomerular blood flow and pressure. The mechanism of this phenomenon is not known. The effect of protein intake on renal function is thought to be hormonally mediated. Since growth hormone can increase renal blood flow as well as GFR, we tested the hypothesis that the presence of growth hormone is necessary for the increase in glomerular filtration rate (GFR) seen after the ingestion of a protein meal. We evaluated the change in GFR after a standardized mixed protein meal in 13 patients with growth hormone deficiency. Neither basal creatinine clearance after an overnight fast (76 +/−17 ml/min/m2; mean +/−SD) nor maximum increment after a 50 g/m2 protein meal (33 +/−11 ml/min/m2) differed in these growth hormone-deficient patients from 16 normals controls (76 +/−18 and 30 +/−15 ml/min/m2, respectively). Twelve hours after an injection of exogenous growth hormone, 0.06 mg/kg up to a maximum of 5 mg, the GFR response to a protein meal did not differ from the pretreatment response (77 +/−19 and 32 +/−17 ml/min/m2, respectively). We conclude that the presence of physiologic amounts of growth hormone is not necessary for the GFR response to a standard protein meal.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720277

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

We have determined the effects of orange juice on calcium bioavailability from CCM (a combination of CaCO3, citric acid, malic acid, 5:1:1, mol/mol/mol) and iron-calcium interaction by using whole body isotope retention techniques in rats. The mean calcium retention values from CCM were 42.8% from orange juice and 33.0% from water, a control. Orange juice significantly (p less than 0.05) improved calcium bioavailability. This enhancement of calcium absorption is independent of orange juice's pH and citric acid. Iron absorption from orange juice with CCM (36.7%) was also significantly higher than that from control (water) plus CCM (12.3%). Ascorbic acid at levels naturally present in orange juice failed to improve iron retention (12.3% vs 12.5%) from water plus CCM. In contrast, citric acid (at orange juice level) significantly (p less than 0.05) promoted iron absorption in the presence of CCM (8.0% vs 23.7%). The benefit of citric acid on iron-calcium interaction is enhanced by ascorbic acid. In the presence of both citric acid and ascorbic acid, at orange juice levels, iron absorption from water plus CCM (37.6%) was comparable to that from water without CCM (34.5%). These results show orange juice can deliver bioavailable calcium from CCM with minimal inhibition of iron absorption. Citric acid and ascorbic acid are likely the major orange juice components that contribute to the alleviation of iron absorption inhibition by CCM.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720278

出版商:Routledge    

年代:1989

数据来源: Taylor

摘要:

The relationships between plasma HDL cholesterol, apolipoprotein A-I, and plasma ascorbic acid were examined in 146 women and 92 men in a Chinese population in Boston, aged 60 and above. A significant partial correlation (r = 0.21, p = 0.015) between plasma ascorbic acid and plasma HDL cholesterol was observed among (predominantly nonsmoking) females after the effects of potentially confounding variables were taken into account. A similar relationship among 26 nonsmoking men was suggestive but inconclusive; there was no evidence of a relationship among 66 male smokers. The partial correlation between plasma apolipoprotein A-I and plasma ascorbic acid was marginally significant for women (r = 0.22, p = 0.057, n = 87) but was highly significant for men (r = 0.43, p = 0.007, n = 51). The correlation coefficient for men was highly dependent on smoking status, being 0.80 for those who never smoked and almost zero for current smokers.

ISSN:0731-5724    

DOI:10.1080/07315724.1989.10720279

出版商:Routledge    

年代:1989

数据来源: Taylor