Influence Of Short-term Fasting Research Articles

Influence of short-term fasting on oxidative stress, antioxidant-related signaling molecules and autophagy in the intestine of adult Siniperca chuatsi

Starvation is a challenging issue in fish growth. In this study, we assessed the effect of short-term fasting on reactive oxygen species (ROS) content, antioxidant activity, the mRNA level of antioxidant and autophagy-related signaling genes and autophagosome formation in the adult Siniperca chuatsi intestine. The results revealed that the ROS and MDA content increased during short-term starvation. Furthermore, GSH content and the activity of SOD, CAT, GST, and GPX increased significantly after a three-day fast, whereas glutathione reductase (GR) activity did not change. Meanwhile, the expression of antioxidant-related signaling genes such as NRF2 was upregulated. As for autophagy-related genes, the expression of Atg4b, BECLIN1 and LC3b did not change after three days of fasting, but significantly upregulated after seven days of fasting, while S6K1 exhibited a decreasing trend. The expression of mTOR decreased significantly after seven days of fasting. Both the mRNA and protein levels of LC3b increased significantly. The results of transmission electron microscopy indicated that the autophagosomes did not changed significantly in the three-day fasting group, but after seven days of starvation and resumed feeding for three days, autophagosomes in the intestine increased significantly. The results indicate that short-term fasting causes a range of physiological and molecular responses in the adult S. chuatsi intestine, which includes alterations in antioxidant signaling genes, antioxidant capacity and subsequently autophagy. Our findings provide a potential insight in the molecular regulatory mechanism of short-term fasting in the intestine of adult S. chuatsi.

Influence of Short-Term Fasting on the Changes in Women’s Cardiovascular Functional Parameters

Research background and hypothesis. Recently, cardiovascular diseases (CVD) have been the major cause of mortality as a result of poor diet, emotional stress and insuffi cient physical activity. Improvement of dietary habits based on reduction of body weight by short-term or long-term fasting has been observed. While analyzing the effect of fasting, its psychological rather than physiological features are usually emphasized.Research aim was to assess the impact of daily fasting on the changes in women’s cardiovascular functional parameters during physical load. Research methods. Thirty six women performed exercise test on bicycle ergometer (the load increased each minute by 25 W) before and after 24 hours of fasting. After the 1 st exercise test the subjects used only non-energetic liquid. Evaluation of electrocardiogram (ECG) data was performed applying computerized ECG analysis system “Kaunas–Load“(Institute of Cardiology, LUHS). We analyzed systolic blood pressure (S), heart rate (HR) and JT interval at rest and throughout the load.Research results. After 24 hours of fasting, HR of women at rest and during the fi rst 3 minutes of the load signifi cantly decreased (p < 0.05). Duration of the JT interval decreased during both exercise tests. Longer JT interval was obtained at rest and during the fi rst 2 minutes of the load after 24 hours of fasting (p < 0.05). S at rest and throughout the load was signifi cantly lower after fasting (p < 0.05). Discusion and conclusions. Functional state evaluation of untrained women after 24 hours of fasting during bicycle ergometery test demonstrated dynamical changes of many cardiovascular function variables: lower HR, increased the JT interval, and decreased S.Keywords: cardiovascular system, short-term fasting, bicycle ergometer test.

The Influence of Short-term Fasting on Muscle Growth and Fiber Hypotrophy Regulated by the Rhythmic Expression of Clock Genes and Myogenic Factors in Nile Tilapia.

Circadian clock genes and myogenic factors are tightly integrated to influence muscle growth upon dietary deprivation in animals. In this study, we reported that upon short-term fasting of Nile tilapia juveniles for 7 and 15days, the growth of the fish stagnated and the size of muscle fibers decreased. To reveal the molecular mechanisms of how starvation affects fish muscle growth, we analyzed the rhythmic expression of circadian clock genes and myogenic factors. After 7 and 15days of fasting treatment, the muscle tissues were collected for 24h (at zeitgeber times ZT0, ZT3, ZT6, ZT9, ZT12, ZT18, ZT21, and ZT24) from tilapia juveniles. Among the 27 clock genes, the expression of cyr1b, nr1d1, per1, clocka, clockb, ciarta, and aanat2 displayed a daily rhythmicity in normal daily cycle, while arntl2, cry1a, cry1b, npas2, nr1d2b, per2, per3, rorαb, clocka, clockb, nfil3, cipca, and cipcb exhibited daily rhythmicity in the fasting fish muscles. The transcript levels of clockb showed moderate positive correlation with the aanat2, ciarta, cry1b, and nr1d1 in the muscle tissue of normally fed Nile tilapia juvenile. In comparison of the two treatment modes, the expression levels of clocka, clockb, and cry1b showed the rhythmicity, but clockb expression was significantly decreased and the acrophase had shifted. The transcript levels of fbxo32 and pdk4 had either moderate or strong positive correlations with other daily expression of clock genes except arntl2 in the muscle after 7-day fasting. The expressions of myogenic regulatory factors were also either upregulated or downregulated. These observations demonstrated that dietary starvation might affect fish muscle growth by modulating the differential expression of circadian clock genes and myogenic factors. Thus, our work provides a better understanding of the molecular mechanism of dietary starvation on fish growth and may provide dietary administration in aquiculture.

OR36: Influence of Short-Term Fasting and Carbohydrate Administration on Gut Immunity and Mucosal Morphology in Mice

OR36: Influence of Short-Term Fasting and Carbohydrate Administration on Gut Immunity and Mucosal Morphology in Mice

Influence of short-term fasting during the luteal phase of the estrous cycle on ovarian follicular development during the ensuing proestrus of ewes

Short-term fasting of mature ewes during diestrus results in increased serum concentrations of progesterone and a delayed pre-ovulatory surge release of LH. To determine if these changes in reproductive hormones influence subsequent follicular development, mature ewes observed in estrus were assigned randomly to control ( n = 10) or fasted ( n = 15) groups. Control ewes had ad libitium access to feed, whereas fasted ewes were not fed from day 7 through 11 of their estrous cycle. Daily blood samples were collected from control and fasted ewes throughout the fasting period. Fasting increased ( P < 0.001) serum concentrations of progesterone (4.4 ng/mL versus 2.7 ng/mL [±0.3]). On day 12, all ewes were treated with 10 mg of PGF 2α and fasted ewes were returned to ad libitum feed. Ovaries were collected from ewes ( n = 5 each group) at 0 and 72 h following PGF 2α in control and 0, 72 and 96 h in fasted ewes. Ovaries were weighed and small (≤2 mm), medium (3–4 mm), and large (≥5 mm) follicles were enumerated. Total numbers of follicles were less ( P < 0.001) in fasted than fed ewes (14.6 versus 30.2 [±2.2]) at 0 h, but did not differ ( P = 0.9) when numbers of follicles were compared at similar times before the anticipated LH surge (i.e., at 72 h versus 96 h in control and fasted ewes, respectively). Within follicular size class, numbers of small and medium follicles were decreased ( P = 0.04) at 0 h in fasted ewes. Numbers of large follicles did not differ ( P = 1.0) between groups. Although numbers of small and medium ovarian follicles in fasted ewes recovered by 96 h to values comparable to fed ewes at 72 h following PGF 2α, serum concentrations of estradiol 17β ( P = 0.08) and FSH ( P = 0.06) tended to be decreased in fasted ewes before the anticipated surge release of LH. Pituitary content of LH and FSH also tended to be lower ( P ≤ 0.09) at 96 h in fasted ewes than at 72 h in control ewes, but did not differ ( P ≥ 0.4) at hour 0 following PGF 2α. Hypothalamic and stalk median eminence contents of GnRH were not influenced ( P ≥ 0.2) by fasting at any time period. Fasting during the luteal phase perturbs gonadotropin secretion and may influence fertility by causing a delay in ovarian follicle development.

The influence of short-term fasting on the quality of small bowel graft preservation

Introduction Donor nutritional status may be a determinant of small bowel (SB) quality following storage. In this study, we investigated the effect of donor nutritional status and a proven nutrient-rich preservation solution on graft quality following cold storage. Methods Rats were fasted (12–14 h) or non-fasted. SB ( n = 6) was flushed vascularly with modified University of Wisconsin (UW) solution and flushed luminally with UW or an amino acid-rich (AA) solution as follows: Fasted. UWV, none; UWL, UW solution; AAL, AA solution. Non-fasted. UWV, none; UWL, UW solution; AAL, AA solution. Energetics, peroxidation (malondialdehyde; MDA), glutathione and histology were assessed over 24 h at 4 °C. Results Energetics (ATP, ATP/ADP, and energy charge) were significantly higher in AAL (fasted and non-fasted) groups than other groups. However, there were no differences in energetics parameters between fasted and non-fasted animals in all groups. MDA was higher in fasted groups than non-fasted tissues; interestingly, AAL values were up to 10-fold lower than other groups. Higher glutathione levels were detected in non-fasted AAL tissues. Mucosal integrity was markedly superior in luminally treated tissues (UWL and AAL) in fasted and non-fasted states. Most noteably, AAL tissues from fasted animals exhibited grade 2 injury (villus clefting), whereas normal mucosa was observed in non-fasted tissues (grade 0). Conclusion Luminal flushing and a nutrient-rich preservation solution improve energetics, oxidative stress, and mucosal integrity during storage. Poorer donor nutritional status does not affect energetics throughout storage, but causes mucosal injury as a result of increased oxidative stress, even after a brief period of donor fasting.

Suppressive effects on allergic contact dermatitis by short-term fasting.

Fasting alters various hormonal and immune conditions. It has been reported that delayed type immune response to the injection of keyhole limpet hemocyanin was depressed by short-term fasting. In this study, we adopted the computer-assisted image analyzer for histopathological analysis and evaluated the influence of short-term fasting on allergic contact dermatitis induced by 2,4-dinitrofluorobenzene (DNFB). Mice were sensitized by painting of DNFB to the abdomen. After the sensitization, mice were challenged by DNFB painting to the ear. Fasting started 24 hour before (48-hour fasted group) or immediately after (24-hour fasted group) the challenging. Fasting without DNFB treatment did not induce remarkable change of ear thickness, ear tissue, serum albumin, serum total protein, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase. or serum creatine phosphokinase. In contrast, lasting suppressed the increment of ear thickness in the DNFB-treated group in this study. We could also demonstrate, using the computerized image analyzer, that both lymphocyte infiltration and the edema in the dermis were suppressed in fasted mice treated with DNFB. Further, edema in the dermis was inhibited more strongly in 48-hour fasted mice than in 24-hour lasted mice. These findings indicate that short-term fasting induce histopathological changes in the state of contact dermatitis.

Effects of Winter Fasting and Refeeding on White-Tailed Deer Blood Profiles

This study examined the effects of dietary protein, fasting, and refeeding on blood characteristics of 9 nonpregnant, female white-tailed deer (Odocoileus virginianus) in captivity from 23 February to 3 May 1984. Percent weight loss was greater in fasted deer than in deer fed diets of 2 crude protein levels. Fasting effects were also observed for hemoglobin (Hb), red blood cell (RBC) counts, packed cell volume (PCV), cholesterol, triglycerides, serum urea nitrogen (SUN), potassium (K), glucose, phosphorus (P), insulin, thyroxine (T4), and total protein (TP). Refeeding influenced cholesterol, sodium (Na), and calcium (Ca). Hemoglobin, PCV, Ca, P, and albumin varied with time in fasted deer. Changes over time in the fed deer occurred for several hematological and serum characteristics. Data are presented to serve as reference values for better understanding of data collected from free-ranging deer under less known conditions. J. WILDL. MANAGE. 51(4):865-873 Winter nutrition is most influential on whitetailed deer survival and reproductive success in the northern portions of their range. Artificial feeding in late winter has not always reduced starvation losses, perhaps due to the tardiness of such efforts and the irreversibility of moribund deer (deCalesta et al. 1977). Therefore, more sensitive evaluations of deer nutritional status that anticipate irreversible deterioration of body condition are needed. Numerous studies document the effects of varying dietary protein and energy levels on blood characteristics of captive deer (Seal et al. 1981, Warren et al. 1982, Card et al. 1985). Several examinations of free-ranging deer on northern and southern ranges have described effects of habitat quality and seasonality on blood characteristics (Anderson et al. 1972, White and Cook 1974, Coblentz 1975, Seal et al. 1978a, Kie et al. 1983, Waid and Warren 1984). Results of these studies have varied, depending on the treatment and environmental conditions. Serum urea nitrogen has been the most thoroughly tested and consistent indicator of nutritional condition; however, it has limitations (Warren et al. 1982). Thus, supportive indicators have been sought and examined. Furthermore, research into the potential effects of chemical immobilization and physical restraint on blood characteristics of deer has permitted more accurate interpretations of data relative to nutritional status (Seal et al. 1972a, Mautz et al. 1980). Few deer studies, however, have focussed on the blood effects of complete nutritional deprivation. Only work by deCalesta et al. (1975, 1977) noted the effects of early and prolonged fasting on SUN, glucose, and non-esterified fatty acids (NEFA) in Rocky Mountain mule deer (0. hemionus), whereas Card et al. (1985) examined the influence of short-term fasting in whitetailed deer on serum cholesterol, ketones, and NEFA's. To identify additional indicators of starvation, we studied the effects of dietary protein and fasting during mid-late winter and recovery in early spring on blood and urine characteristics. Here we describe our findings relative to extensive blood profiles; the urinalysis information is reported separately (DelGiudice et al. 1987). We appreciate the financial support of the Spec. Projs. Found., Minneapolis Big Game Club; the Natl. Rifle Assoc.; the U.S. Fish and Wildl. Serv.; the Res. Serv., Veterans Adm.; the Minn. Zool. Soc.; R. Shelton; the James Ford Bell Found.; Safari Club Int.; and the Minn. Dep. Nat. Resour. We thank F. B. Martin for statistical consultation, and M. D. Lewis, N. I. Manning, M. K. Twite, K. D. Kerr, W. J. Paul, S. H. Fritts, E. H. Stege, K. Johnson, J. Lazar, and R. J. Welters for technical assistance. 'Mailing address: North Central Forest Experiment Station, 1992 Folwell Avenue, St. Paul, MN 55108.

Influence of Short-Term Fasting on the Pituitary-Testicular Axis in Normal Men

To investigate whether short-term fasting affects serum testosterone (T) in normal subjects, 10 healthy men of normal weight were studied on two occasions: after an overnight fast (8 h), and after an additional 48 h of fasting. Blood glucose declined by 22 +/- 3% between the tests (p less than 0.001). Basal serum T fell from 8.7 +/- 0.7 to 5.7 +/- 0.8 micrograms/l (p less than 0.01), and LH from 6.9 +/- 0.8 to 5.0 +/- 0.7 U/l (p less than 0.01). Serum estradiol (E2) and FSH remained unaffected. To explore possible mechanisms behind the decreased basal release of T and LH, 9 small doses of glucose were given orally at regular intervals during a 56-hour fast to 9 additional normal men to maintain blood glucose levels. These men did not experience a fall in serum T or LH. Six additional normal men were given 50 micrograms GnRH intravenously after an overnight fast, and after a fasting period of 56 h. No acute increase in T was seen after the overnight fast, but after the 56-hour fast GnRH raised serum T by 55 +/- 14% (p less than 0.02). Moreover, fasting augmented the GnRH-induced LH response by 64 +/- 15% (p less than 0.02. These results imply that: short-term fasting exerts inhibitory influence on Leydig cell function via a mechanism which might involve a reduced hypothalamic and/or pituitary stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of Short Term Fasting on Chicken Alimentary Canal Mucosa

Little is known about the physiological effects of short-term fasting in avian species. The present study was developed to examine the alimentary mucosal changes in fasted birds by scanning and transmission electron microscopy. Chickens of various ages were fasted for periods of 3, 5, and 7 days. Water was provided ad libitum. At the end of the fasting periods the birds were sacrificed along with ad libitum fed controls. Tissue samples from crop, duodenum, and ileum were processed by standard methods for scanning and transmission electron microscopy (SEM and TEM). The SEM samples were prepared by vacuum drying methods. The TEM samples were embedded in Spurrs embedding medium. Mucosal sloughing was observed in the crop and small intestine with SEM only in fasted birds. With TEM, separation was observed between the mucosal cells of fasted birds with membranous whorls in these spaces. Sloughed cells may be an endogenous protein source for the fasting bird.