30 adult animals (14 females, 16 males) were studied macroscopically. The main findings are as follows: 1. The intestine is without striking macroscopic features that characterize the different parts of it. A variation of position of ileum, cecum, and colon, respectively, is due to the length of their mesenteries. 2. In adult males, the intestines are displaced from their position in the caudal part of the abdomen by the urethra (the urethral diameter is even wider than that of the gut, because the wall contains masses of prostatic glandular tissue). 3. The liver is clearly divided into lobes, however, there is no notch between the quadrate lobe and the left medial lobe. The falciform ligament is regarded as the border-line between these lobes, while the gall bladder separates the quadrate lobe from the right medial lobe. 4. The spleen lies almost entirely caudal to the costal arch. It extends dorsally between the stomach and the left kidney. Along the body wall, it reaches the ventral median line and shows even a slight orientation towards the xiphoid cartilage. 5. The greater omentum may extend to the cranial end to the urinary bladder. It is extremely thin and therefore hardly visible. 6. In females, subperitoneal fat may extend from the caudo-dorsal body wall along the lateral walls down to ventral regions, in some cases even occupying a considerable part of the caudo-ventral abdomen.
Urethane-anesthetized and conscious, immobilized SHR subjected to osmotic diuresis, responded to intravenous saline loading with a larger natriuresis than WKY-rats due to an increased urine sodium concentration without differences in urine flow. Blood pressure and heart rate reactions after saline loading were qualitatively different in anesthetized and conscious rats. The magnitude of these changes was larger in WKY than in SHR in both experimental groups.
Generally, in order to collect faeces and urine of cats, the animals are housed in metabolism cages with wire-mesh bases. We have developed an alternative method to collect faeces and urine quantitatively and separately, using cages with solid floors. The use of such cages allows long-term experiments to be carried out without increased risk for injury to feet or legs. Modified litter boxes were constructed so that faeces and urine were separated and the cats could bury their faeces. With the use of this method the excretion of calcium, magnesium and phosphorus by mature cats was determined. Mineral retention over a period of ten days did not differ significantly from zero, suggesting that the method developed is valid for the measurement of mineral excretion. Evidence is presented that under our experimental conditions faeces should be collected for at least five days so as to cancel out largely the impact of day-to-day variation in defecation on the variance of mineral retention.
The influence of different amounts of oral sodium intake combined with high oral water intake on potassium excretion and plasma potassium concentration (PK) was evaluated. Female beagle dogs (11-16 kg) were divided into 2 groups: 1. Normal Sodium and high Water Intake (NSWI): 2.5 mmol Na, 3.55 mmol K, 91 ml H2O, and 277 kJ per kg body mass and 24 h (31 24 h-balance studies with 11 dogs). 2. High Sodium and high Water Intake (HSWI): Same diet as NSWI but 14.5 mmol Na x kg body mass-1 x 24 h-1 (55 24 h-balance studies with 21 dogs). The 24 h-balance studies were performed after different periods of time after onset of the respective diet (dogs in metabolic cages). Plasma sodium concentration (PNa) on NSWI was 148.4 +/- 2.6 mmol x 1(-1), whereas it was lower on HSWI (145.9 +/- 2.4 mmol x 1(-1). The lower plasma aldosterone concentration (PAC) on HSWI (24 +/- 8 pg x ml-1) compared to NSWI (67 +/- 38 pg x ml-1) may account for the lower PNa on HSWI. 24 h-sodium excretion was 93.6 +/- 6.5% of intake (%i) on HSWI and 91.5 +/- 20.7% i on NSWI. 24 h-water excretion was not different between both groups (81 +/- 7% i). PK was 3.93 +/- 0.25 mmol x 1(-1) on NSWI regardless of the time the dogs were on NSWI.(ABSTRACT TRUNCATED AT 250 WORDS)
The purpose of this investigation was to follow the course of the serum cholesterol, serum triglyceride and HDL cholesterol concentrations of heritable hyperlipidemic (HHL) rabbits (34 animals in total) in order to obtain an early prediction of these parameters, which appear to be highly associated with the presence of arteriosclerotic lesions. Measurements were done at 6-week intervals for one year, beginning at the 10th week of age. At week 10 the serum cholesterol concentration of females was 652.80 mg x dl-1 +/- 103.82 (standard deviation) and that of males was 648.84 mg x dl-1 +/- 146.04. The 10-week serum triglyceride concentration of males was 267.90 mg x dl-1 +/- 93.03, which decreased in two marked steps after week 10 and 40, while that of females was 246.70 mg x dl-1 +/- 67.51, which reached a maximum at 7 months and then decreased. Both the serum cholesterol and the serum triglyceride concentrations decreased significantly in males and females during the investigation period. The 10-week HDL cholesterol concentrations (males: 18.08 mg x dl-1 +/- 12.81; females: 14.61 mg x dl-1 +/- 8.56) remained relatively constant in both sexes during the investigation period. We consider one or two samplings, usually at weaning and at the beginning of an investigation, to ensure reliable biochemical parameters for the state of the animals.
To examine the effects of age and body mass of recipients on embryo survival during gestation, ICR embryos were transferred to nulli- or primi-parous females of 4 strains of mice. Out of 530 recipients, 383 (72.3%) produced a litter. Transfer of 3,465 embryos to 383 recipients resulted in production of 1,637 pups born alive, an overall rate of embryo survival of 47.2 +/- 1.1%. Regression analyses revealed that embryo survival decreased in older recipients and increased in heavier recipients. The results were consistent in each parity/strain group and all groups combined.
On the principle of the single-radial-immunodiffusion a method has been developed to estimate serum vitellogenin quantitatively in maturing rainbow trouts. Serum vitellogenin (VG) content correlates with the egg diameters. Thus it is possible both to establish the beginning of the egg maturation and to monitor it in a simple way.
The effects of group size (individually versus 3 in a cage) and gentling on behaviour and blood constituents were studied in female rats. Gentled rats showed less freezing and/or escaping when approached in an objective handling test than non-gentled rats; the type of caging had no significant influence. In a small field, gentled rats displayed significantly more turning and standing upright, whereas these parameters did not differ between rats housed either individually or three in a cage. In both tests, gentled rats produced significantly less urine than did control rats. Neither caging nor gentling significantly influenced the group mean values and variance of masses of adrenals, spleen and thymus and plasma concentrations of glucose, cholesterol, triglycerides and corticosterone. Removal of a cage from the rack and getting out a rat caused increase in plasma concentrations of corticosterone in its remaining cage mates.
The microflora of the gastro-intestinal tract of dystrophic BIO 8262 Nij Syrian hamsters and Kun:Sh Syrian hamsters as controls was investigated by means of culturing techniques and scanning electron microscopy. The oesophagus, forestomach, stomach, small intestine, coecum and faeces were assessed for the presence of Enterobacteriaceae, Staphylococci, Lactobacilli, Streptococci, Clostridia, Bacteroides and yeasts. The normal hamsters showed low levels of yeasts in the oesophagus, forestomach and stomach; yeasts were not present in the other compartments. Relatively low levels of Staphylococci and Enterobacteriaceae were found in all gut segments; also Bacteroides was found in low levels in the upper part of the gut. The other groups of bacteria showed relatively high levels in all segments. In dystrophic BIO 8262 Nij hamsters no Enterobacteriaceae and yeasts have been detected in the gut. Scanning electron microscopy showed no difference in adhesion between both hamsters strains.
The study compared the fertility of nulliparous Jcl:SD rats, young mature (12-week-old) versus middle aged (47-week-old) or old animals (64-week-old), both groups near the termination of their reproductive capability. Trypan blue (TB) was given subcutaneously at 0 (control), 10 or 50 mg/kg on days 7 through 9 of gestation to increase the malformation rate. However, no clear teratogenic action of TB was observed. The dose of 10 mg/kg TB was well tolerated, while 50 mg/kg was of severe maternal toxicity and 14 of 53 females died. In comparison with the young control group, the average per litter from middle aged or old dams was significantly decreased for implantation sites, live fetuses and fetal weight, while the percentages of pre-implantation loss and dead implants were extremely high. No increase of the malformation rate occurred with maternal aging. Histologically, middle aged and old rats exhibited age-related lesions of the pituitary, adrenals and reproductive organs with pituitary adenomas, cystic endometrium and sclerotic atrophy of uterine glands being significantly increased in non-pregnant, old rats.
Food consumption, development of body weight, lifespan and incidence of spontaneous diseases and tumours were investigated in 3 groups of 96 male Han:SPRD rats each maintained in a longevity study from weaning up to their natural death. All rats were fed a commercial cereal-based diet. One group received food ad libitum and was used as control group. Access to the diet was controlled in the other two groups by means of an automatic timer. The rats of one of the latter groups were fed nocturnally (4 x 42 min daily during the dark period) and those of the other adiurnally (4 x 42 min daily, each two times during dark and light period). Time-scheduled feeding caused an evident food restriction compared with the food consumption of the rats fed ad libitum. This food restriction, however, was significantly more pronounced in the younger animals during the first weeks after weaning than in the older rats. The body weight development corresponded to the feed intake. In animals subjected to food restriction the weight remained below that of rats fed ad libitum during all age periods. Furthermore, time-scheduled feeding caused an important increase of the mean life expectancy and a reduction in the incidences of chronic nephropathy and purulent and chronic forms of prostatitis. Only a slight effect of controlled feeding was observed on the incidence of alveolar lipoproteinosis. Time-scheduled feeding did not cause a reduction in the incidence of tumours, but it delayed their occurrence. The risk to develop various types of tumours during the third year of life was significantly higher in the ad libitum group than in the rats fed by a controlled regime. The automaton Han:CHRONOFEEDER, used in this study, has proved to be an appropriate, relatively inexpensive and easily installable feeding system for automatic control of food accessibility. It is suitable to implement controlled feeding and food restriction of rodents in longterm experiments.
