[Intracellular regeneration of neurons in the rat lateral hypothalamic area of the brain after resumption of food intake]

Electron microscopy was used to explore changes in intracellular regeneration processes in neurons of the anterior, medial and posterior parts of the lateral hypothalamus area (LHA) of rats at various time (10, 20, 30, 50 and 70 days) after resumption of food perception. Ultrastructural changes observed during 7 days of food deprivation in intact neurons were of a reversible character. Recovery processes initially appeared and finished earlier in the neurons of medial (day 30) and anterior (day 50) parts of the LHA, in the posterior part of LHA the normalization of the neuronal structure was slower and was over only by the 70th day after the resumption of food reception. The above data are both of theoretical and practical importance, serving as a base for the study of directed treatment of diseases caused by hunger.

Epithelial cell proliferation and intestinal absorptive function during starvation and refeeding in the rat

1. Intestinal epithelial cell production and intestinal absorption were measured in fed, starved and refed rats. 2. Four days' starvation significantly decreased the crypt cell production rate (CCPR), absorption, small intestinal length and crypt cell population. 3. There was an immediate increase in absorption 1 day after refeeding, which preceded a slower increase in CCPR. The absorption rate then decreased progressively after refeeding, and was significantly lower than control levels 1 week after refeeding. The CCPR, however, increased more gradually, reaching control levels after 2 days and then 'overshooting' control values. 4. There was no significant change in the crypt cell population immediately after refeeding; thus we propose that the initial increase in absorption on refeeding is either due to an accelerated maturation rate of the enterocytes or to the migration of enterocytes from the base of the villus to the functional zone. 5. The rapid recruitment of absorptive function appeared to be a 'one-off' event, the villus compartment then having to wait for increased cell production in the crypts to repopulate the villi.

Morphological changes and catalase activity in the hearts of CD 1 mice following acute starvation or single doses of doxorubicin, epirubicin or mitoxantrone

The cardiac morphology of CD 1 mice undergoing two different schedules of acute (5 day) starvation and that of animals treated with a single dose (15 mg/kg i.p.) of doxorubicin, epirubicin or mitoxantrone were studied by light microscopy. Determinations of heart catalase were also carried out. Mice subjected to moderate starvation had a mean weight reduction of 18.7% and did not show heart morphological damage. A slight increase (38%) of heart catalase specific activity occurred in these animals. In animals subjected to severe starvation the weight loss was 32.2%. In this case considerable heart damage, in the form of myofibrillar loss, and a striking increase of catalase (158.5%) were seen. In the drug groups comparable weight reductions (about 15%) occurred 5 days after the treatment. Moderate heart lesions, represented by myolysis and especially by myocytic microvacuolation, were observed and appeared to be of similar degree in the 3 drug groups. Catalase specific activity increased by 119.9% in the doxorubicin animals, by 73% in the epirubicin mice and by 30.3% in the mitoxantrone ones. Light microscopy made it possible to distinguish between cardiac alterations induced by starvation and those specifically induced by antiblastics. Catalase may be helpful to indicate the existence of heart damage but it does not correlate well with the severity of the lesions by antiblastics. An additional cause of heart catalase elevation might be the free radical generation induced by the anthracyclines but not by mitoxantrone.

Significance of increase in glucose 6-phosphatase activity in brown adipose cells of cold-exposed and starved mice

Cytochemical and biochemical glucose 6-phosphatase (G6Pase) activity was examined in brown adipose tissues of normal, cold-exposed, or starved mice. In addition, G6Pase activity in white adipose tissue and hexokinase activity in brown and white adipose tissues were biochemically measured. In normal animals, the reaction product for G6Pase activity was localized in the endoplasmic reticulum and nuclear envelope of brown adipose cells. The amount of the reaction product increased in cold-exposed or starved animals. Biochemical G6Pase activity (259.7 +/- 48.5 ng Pi/min/mg protein) in brown adipose tissues of normal animals was higher when the value was compared with values of other organs. Biochemical G6Pase and hexokinase activities increased rapidly in brown adipose tissues of cold-exposed animals, and a close relation was found between activities of the two enzymes. In brown adipose tissues of animals starved for 3 days, biochemical G6Pase activity increased, but hexokinase activity did not change. In white adipose tissues of normal, cold-exposed, or starved animals, G6Pase activity was very low, although the enzyme activity increased slightly in animals starved for 3 days. The results show that the high G6Pase activity in brown adipose cells probably relates to thermogenesis in cold-exposed animals and may be concerned with glucose release into the blood in starved animals.

[Histostereological analysis of the parenchyma and stroma of the atrophied myocardium in alimentary starvation]

The sexually mature Wistar rats were placed in separated cages and totally deprived of food (but allowed water ad libitum) for 2, 4 and 8 days. Tissue stereological analysis of myocardium included the determination of volume and surface densities of cardiomyocytes, volume density of stroma, volume and surface densities of capillaries and interstitial cells, volume-to-volume and surface-to-volume ratios of the basic components of parenchyma and stroma. The correlation and information analyses of the stereological parameters were carried out. It was shown that the development of myocardial atrophy (a decrease in heart weight and cardiomyocyte diameter) was accompanied by decreasing the volume density of parenchyma and increasing the volume density of stroma. A decrease in the surface of the exchange between the cardiomyocytes and microcirculatory bed was also revealed in alimentary starvation.

Superinduction of the Dictyostelium discoideum cell surface cAMP receptor by pulses of cAMP

Extracellular cAMP plays a crucial role in regulating the developmental program of Dictyostelium discoideum, functioning as a chemotactic agent, as well as a signal that regulates expression of developmentally expressed genes. These activities appear to be mediated by a cell-surface receptor for cAMP. We have studied the regulation of this receptor in cells developed in starved suspension cultures exposed to 50 nM pulses of cAMP every 6 min. cAMP-pulsed cells display roughly 10-fold higher cAMP receptor levels than cells that developed on filters or that were starved in suspension without cAMP pulses. Based on saturation binding analysis, the superinduced binding activity represents an increase in receptor number, while receptor affinity for cAMP is unaffected. Photoaffinity labeling of superinduced cells results in specific labeling of the same molecules that are labeled in starved cells. This increased cAMP binding activity was also detected in membrane preparations from cAMP-pulsed cells. These results provide evidence for an unusual mode of receptor regulation: autogenous induction of the receptor by its ligand.

Annulate lamellae of the pancreatic exocrine cells in starved rats

The ultrastructure of annulate lamellae in the pancreatic exocrine cells of rats starved for 3-42 days was studied. Annulate lamellae were rarely encountered in the pancreatic exocrine cells of control rats, but their incidence and size of stack was increased in those of starved rats depending on the duration of starvation, despite marked ultrastructural changes in these cells. Annulate lamellae were located in the para- or infranuclear cytoplasm of the cells and most of them were continuous with the relative normal rough endoplasmic reticulum. A close apposition in parallel was often found between the annulate lamellae and the outer nuclear envelope and occasionally pores in line with those of the nuclear membrane were observed in the lamellae of rough endoplasmic reticulum in 35- and 42-day-starved rats. An unequivocal continuity between the annulate lamellae and the nucleus and/or rough endoplasmic reticulum in pancreatic exocrine cells might be related to their origin and function.

Immunohistochemistry and morphometry of gastrin cells in the rat pyloric antrum during starvation

The gastrin cells (G cells) in the rat pyloric antrum after 7, 14, 21 and 28 days of starvation were investigated by immunohistochemistry and electron microscopy. In the peroxidase anti-peroxidase method for light microscopy, gastrin immunoreactive cells during starvation markedly decreased in number and size. Quantitative electron microscopy revealed that during starvation the number of electron-lucent granules were greatly reduced, but the number of electron-dense granules increased; the number of intermediate granules were not remarkably changed in G cells. These results may suggest that the synthesis of gastrin and granule maturation were greatly inhibited during long-term starvation.

Effects of semi-starvation and potassium deficiency on the concentration of [3H]ouabain-binding sites and sodium and potassium contents in rat skeletal muscle

1. Using vanadate-facilitated [3H]ouabain binding, the effect of semi-starvation on the total concentration of [3H]ouabain-binding sites was determined in samples of rat skeletal muscle. When 12-week-old rats were semi-starved for 1, 2 or 3 weeks on one-third to half the normal daily energy intake, the [3H]ouabain-binding site concentration in soleus muscle was reduced by 19, 24 and 25% respectively. In extensor digitorum longus, diaphragm and gastrocnemius muscles the decrease after 2 weeks of semi-starvation was 15, 18 and 17% respectively. The decrease was fully reversible within 3 d of free access to the diet. Complete deprivation of food for 5 d caused a reduction of 25% in soleus muscle [3H]ouabain-binding-site concentration. It was excluded that the reduction in [3H]ouabain binding was due to a reduced affinity of the binding site for [3H]ouabain. 2. Semi-starvation of 12-week-old rats for 3 weeks caused a reduction of 45 and 53% in 3,5,3'-triiodothyronine (T3) and thyroxine (T4) levels respectively. As reduced thyroid hormone levels have previously been found to decrease [3H]ouabain-binding-site concentration in skeletal muscle, this points to the importance of T3 and T4 in the down-regulation of the [3H]ouabain-binding-site concentration in skeletal muscle with semi-starvation. Whereas potassium depletion caused a decrease in K content as well as in [3H]ouabain-binding-site concentration in skeletal muscles, semi-starvation caused only a tendency to a decrease in K content. Thus, K depletion is not a major cause of the reduction in [3H]ouabain-binding-site concentration with semi-starvation. 3. Due to its high concentration of Na,K pumps, skeletal muscle has a considerable capacity for clearing K from the plasma as well as for the binding of digitalis glycosides. Semi-starvation causes a severe reduction in the total skeletal muscle pool of Na,K pumps and may therefore be associated with impairment of K tolerance and increased digitalis toxicity.

Cardiac function during protein malnutrition and refeeding in the isolated rat heart

In an attempt to elucidate the effect of protein restriction and subsequent refeeding on cardiac muscle function, 133 rat hearts were studied on a Langendorff perfusion apparatus: 19 normal controls, 55 rats during 6 weeks of protein restriction, and 59 rats during 6 weeks of refeeding following starvation. During starvation animals lost 14.3% of body weight and 12.8% in heart weight, both to be gained upon refeeding. Both developed force and force velocity tended to decrease in starving rats compared to control or refeeding rats. This trend was present at time 0, but more so after 60 min of perfusion. Furthermore, these differences became even more obvious and significantly different at the higher heart rates of 300 and 400 beats/min, and less so at 100 or 200 beats/min. These protein malnutrition-associated cardiac function derangements reversed almost completely to normal upon refeeding.

Ileal hyperplastic response to starvation in the rat

The ability to respond to changes in the external and internal environments is a fundamental characteristic of intestinal structure and function. We compared the responses of the rat proximal and distal small intestine to the stresses of fasting and refeeding in the rat. In the duodenum, 3 days of starvation caused villus and crypt hypoplasia, reduced incorporation of [3H]thymidine into crypt cells, decreased cell migration rate on the villus, and lowered specific and total activities of several cellular enzymes. These changes were reversed by 1 day of refeeding. In contrast, mucosal hypoplasia did not occur in the ileum during fasting, and the specific activities of the disaccharidases were increased after 3 days of starvation. However, ileal [3H]thymidine incorporation, thymidine kinase activity, and ornithine decarboxylase activity decreased during starvation. These effects were also reversed by refeeding. The results of these studies illustrate differing responses for the proximal and distal small intestine and suggest the presence of distinctly differing mechanisms for the control of their mucosal mass and enzyme activities.

Starvation-induced microautophagic vacuoles in rat myocardial cells

During prolonged starvation the heart atrophies and loses protein mass. Debate lingers over the basic mechanisms in the production of negative cardiac protein balance during starvation. The extent to which cardiac proteolysis takes place within the lysosomal vacuolar system is unknown. The present communication examines the starvation-induced changes within the lysosomal system of rat myocardial cells, as studied by means of conventional electron-microscopic techniques. Special attention has been paid to the occurrence of microautophagic vacuoles. It is concluded that during prolonged starvation microautophagic vacuoles appear in rat myocardial cells, suggesting the induction of a microautophagic pathway of lysosomal proteolysis.

Polyribosome concentration in human skeletal muscle after starvation and parenteral or enteral refeeding

Posttraumatic and septic states cause a loss of body proteins resulting in a negative nitrogen balance. The major part of the excreted nitrogen is derived from the proteins of skeletal muscle. The loss in proteins is due to a decrease in protein synthesis rather than an increase in protein degradation. Nutritional support may increase protein synthesis, and determination of its activity in skeletal muscle will give information on the utilization of nutrients in catabolic patients. The effect of nutritional support on healthy subjects was studied to achieve a background for future clinical studies. Male volunteers between 20 and 40 years old were refed parenterally or enterally after three days of starvation. Muscle biopsies (50 mg) were analyzed for the size distribution of ribosomes in a sucrose density gradient, and the ribosome concentration was determined per mg of DNA. Changes in the percentage content of polyribosomes preceded those of the total ribosome concentration. The total polyribosome concentration per gram wet weight of skeletal muscle decreased significantly during starvation. After one and two days of refeeding, a significant increase was observed, but the original level of the nonstarved subjects was not reached. The total ribosome concentration increased upon refeeding, but was not significantly different from that of the starved condition. The nitrogen balance was negative during starvation but attained equilibrium after two days of refeeding. Nutrition administered by the parenteral or enteral route were equally effective in restoring protein synthesis.

Quantitative changes in the lysosomal vacuolar system of rat hepatocytes during short-term starvation. A morphometric analysis with special reference to macro- and microautophagy

Ultrastructural morphometric analysis was used to study time-dependent variations in macro- and microautophagy in rat hepatocytes. Except during periods of short-term starvation for up to 24 h, animals were kept under standardized conditions of food intake. In hepatocytes of meal-fed rats the volume fraction of macroautophagic vacuoles is significantly higher at 23:00 h, i.e., immediately before food intake, compared to 11:00 h, i.e., 12 h following feeding. During fasting, macroautophagy drops to a low level. Microautophagic vacuoles in hepatocytes of meal-fed rats, sacrificed at 11:00 or 23:00 h respectively, do not show any significant quantitative differences. However, during 12 h of starvation, the volume fraction of microautophagic vacuoles rises significantly, whereas the numerical density remains constant. Subsequently, during the second 12-h period of fasting, the volume fraction of microautophagic vacuoles remains unchanged, but the numerical density increases. Over a period of 24 h of starvation the volume fraction of the total lysosomal system does not change significantly, whereas the numerical density rises. The time-dependent changes of the macroautophagic vacuolar system correlate with the circadian, food-related variations in the protein content of individual hepatocytes from meal-fed animals. The increase in volume fraction and thereafter in number of microautophagic vacuoles, as observed during starvation, coincides with a large decrease in protein content of individual hepatocytes.

Refeeding differentially affects tumor and host cell proliferation

Tumor and host tissue DNA synthesis in C3H female mice with MA16/C tumors were examined for the effects of starvation and refeeding. Animals with subcutaneously implanted tumors were randomized to either regular diet or starvation for 48 hr followed by refeeding for 6, 12, 24, 48, or 72 hr. With starvation, both tumor and host tissues demonstrated a decrease in DNA synthetic activity. After refeeding, resumption in DNA tumor synthesis preceded that of host tissues and was greatest within the first 6-12 hr. Host tissue DNA synthetic activity resumed at different times in the various tissues examined with bone marrow being earlier than spleen or liver. The differential time course between induction of tumor and host DNA synthesis could allow a more precise modeling in studies dealing with the interaction of nutritional repletion and antitumor therapy.

Effects of cold adaptation and starvation on sciatic nerve fibers in the frog

The conditions under which frogs are kept prior to experimentation were found to have a measurable effect on peripheral nerve structure. Frogs kept for 12 weeks at 4 degree C had markedly shrunken sciatic nerve fibers compared with frogs kept at 19 degrees C. Intermediate fiber shrinkage was found for frogs kept at 19 degrees C without feeding. Counts of neurofilaments and microtubules showed that fiber shrinkage was from a preferential loss of filaments, indicating cold- or starvation-induced atrophy of the axon's cyto-skeleton. This effect, however, was superimposed with additional osmotic axonal shrinkage, causing filament densities to increase per area. There were no changes in myelin sheath thickness due to cold adaptation or fasting.

Infanticide by starvation: calculation of caloric deficit to determine degree of deprivation

A review of medical records and autopsy examination of a six-week-old male revealed the cause of death to be severe malnutrition with dehydration. Weight and caloric deficits were calculated to determine the degree of deprivation, which could be expressed as an interval of days for clear courtroom presentation. These calculations may be useful for quantifying the degree of malnutrition in a variety of child abuse cases.

[Appearance of clasmatosis in the normal and pathological liver]

It was established that clasmatosis of cytoplasmic fragments toward sinusoids occurred under normal physiological conditions (embryogenesis of chick liver, the liver of starved grass carp and silver carp) and pathological conditions (disturbance of rat hepato-intestinal circulation). The clasmosomes of rat and chick liver cells contained free ribosomes and small vesicles while those in the liver of starved fish consisted of glycogen. It was also shown that mitochondria with the signs of complete clasmatosis appeared in the hepatocyte cytoplasm immediately after the beginning of intensive bile secretion to the bile canaliculus (in liver cells of rat and chick embryo and in those of frogs after complete metamorphosis). Such mitochondria were partially disintegrated and were located near the bile canaliculi. It is assumed that clasmatosis of the fragments of the liver cell cytoplasm or mitochondria takes places where it is necessary to rapidly supply the body or cell with some products of metabolism or to remove something from the cell as is the case with erythroblasts, i. e. clasmatosis is one of the mechanisms of the adaptation of the cell and its organelles to changes in the environment.

The effect of short-term starvation on mucosal barrier function in the newborn rabbit

The compromised human newborn frequently presents with overwhelming feeding problems which lead to inadequate intake. These problems may affect the development of the small intestine, especially mucosal barrier function, leading to increased infections and susceptibility to allergens. To study this, an animal model was established using neonatal rabbits deprived of nutrients from birth until 72 h. Mucosal barrier function was compared in deprived and control (naturally fed 72-h-old animals) rabbits by measuring immunoreactive bovine serum albumin in serum 4 h after intragastric infusion of crystalline bovine serum albumin (200 mg/100 g body weight). Trypsin activity was measured in rinse fluid obtained from the small intestine. Representative sections of jejunum from control and experimental animals were formalin fixed and stained with hematoxylin and eosin for morphologic comparison. Following the bovine serum albumin feeding, a significantly increased serum immunoreactive bovine serum albumin and significantly decreased trypsin-like activity of the small intestinal rinse fluid was noted in starved animals compared to controls. In addition, the enterocytes of malnourished animals were more cuboidal and contained fewer and smaller supranuclear granules on microscopic examination than the enterocytes of controls. This study suggests that short-term starvation in newborns affects mucosal barrier function. Acute starvation may place newborns at increased risk for infections and allergic disease.

Marrow cell necrosis in anorexia nervosa and involuntary starvation

Marrow specimens from six patients with anorexia nervosa and three with involuntary starvation were examined for the presence of gelatinous transformation and marrow cell necrosis. Five of the patients had pancytopenia. Acanthocytes were present in the circulation of all nine. In only two patients was marrow cellularity adequate. Gelatinous transformation was present in every marrow specimen and was of a marked degree in eight. Marrow cell necrosis was identified in all nine marrow specimens. The necrosis was extensive in one specimen, focal in the others and limited to the areas of gelatinous transformation. Severe malnutrition was the single element common to all the patients.

Effects of starvation on the ultrastructure of the mouse parathyroid gland

Ultrastructural changes of the parathyroid glands of starved mice were examined. The parathyroid glands of the starved mice showed a decrease in the volume of Golgi complexes and storage granules and an increase in the volume of lipid droplets, and contained more heterogeneously dense bodies and multivesicular bodies compared with that of the control mice. In addition, the volume of mitochondria, cisternae of granular endoplasmic reticulum and secretory granules and the number of prosecretory granules appeared to be decreased compared to those of the control mice. Myelin-like structures were observed in the parathyroid glands of the starved mice. The results of our study provide support for the hypothesis that starvation exerts an inhibitory influence not only on the synthesis but also on release of parathyroid hormone.

The effects of intermittent starvation on lung development in suckling rats

The effect of starvation on postnatal lung growth in rats was investigated. Litters were starved twice, each time for 24 hours, on Day 1 and Day 5 after birth. One group of littermates was sacrificed on Day 7, and another group, on Day 14 of postnatal life. Intermittent starvation diminished lung growth. This was accompanied by reduced somatic growth. On postnatal Day 7, lung volume, total number of alveoli, and internal surface area of the lung were decreased in starved rats, but structurally their lungs appeared similar to control lungs. On postnatal Day 14, a striking morphologic difference was observed between the lungs of control and starved pups. Following starvation, retardation of lung growth was manifested in all the parameters studied. One week of normal uninterrupted suckling could not overcome the starvation-induced initial effects on growing lungs. It is concluded that starvation, soon after birth, affects adversely the normal development of lung.