Growth of the Parts of the Alimentary Tract of the Rat, and the Small Intestine of the Sheep, Relative to Growth in Live Weight.

1976 ◽  
Vol 24 (3) ◽  
pp. 383
Author(s):  
VJ Williams
Keyword(s):  
Small Intestine ◽  
Metabolic Rate ◽  
Alimentary Tract ◽  
Causal Relation ◽  
Live Weight ◽  
Dry Weight ◽  
Female Rats ◽  
Percentage Increase ◽  
Male And Female Rats ◽  
Age Range

The dry weight of stomach, small intestine, caecum and colon was obtained from male and female rats from 8 to 184 days old weighing from 18 to 400 g. The length of the colon and small intestine was also measured. The length and dry weight of the small intestine of 35 merino sheep from birth to aged or 3 to 40 kg liveweight were also measured. Regressions between the logarithms of gut measurements and logarithms of the liveweights were calculated. The gut measurements were length, length/kg liveweight, DM, DM/kg liveweight and DM/m for the tubular small intestine and colon, and DM and DM/kg liveweight for the saccular stomach and caecum. For the rat, 2 relations were required to describe the data from all organs. A change in percentage increase or decrease relative to percentage liveweight increase occurred at about 70 to 80 g liveweight or 37 to 44 days old. This is the age range at which increase in metabolic rate relative to liveweight declines to about one-quarter of its previous rate. It is unlikely that there is a causal relation between the maturation of sex hormone output and gut growth and metabolic rate. One allometric regression coefficient adequately described growth of the small intestine of the sheep relative to weight gain.

Variation in the size and position of Hymenolepis diminuta (Cestoda: Cyclophyllidea) within the rat intestine

1969 ◽  
Vol 47 (6) ◽  
pp. 1091-1101 ◽  
Author(s):  
D. F. Mettrick ◽  
Lorna C. Dunkley
Keyword(s):  
Body Weight ◽  
Experimental Design ◽  
Frequency Distribution ◽  
Dry Weight ◽  
Pyloric Sphincter ◽  
Hymenolepis Diminuta ◽  
Female Rats ◽  
Rat Intestine ◽  
Male And Female ◽  
Male And Female Rats

Data on the dry weight of 410 worms from both male and female rats is shown not to differ significantly from the normal (Gaussian) frequency distribution. This finding justified the use of statistics based on this function.Host body weight is shown to have a highly significant (P < 0.01) effect upon worm dry weight. The heavier the rat, the smaller the worms. An experimental design taking rat body weight into consideration is shown to be up to 36% more efficient in demonstrating differences between groups than one that ignores this source of variation. The point of scolex attachment behind the pyloric sphincter also has a significant effect (P < 0.05) upon worm dry weight. The nearer the scolex is to the stomach, the smaller the worm.The distribution of worm biomass in the intestine does not follow a normal (Gaussian) frequency, but is both asymmetrical (P < 0.001) and flattened (P < 0.001). Over 50% of the parasite biomass lies within the second quarter of the intestine. The distribution of the median points of worm strobilae in the rat intestine is also asymmetrical (P < 0.01) with a peak in the zone which represents a distance of 30–35% from the stomach.The migration of H. diminuta within the rat intestine results in the greater part of the parasite body lying in the second quarter of the intestine. The median points of the strobilae are concentrated at the junction of the first and second quarters of the intestine. This region of the rat intestine appears to offer the optimum site for the growth of H. diminuta.

scholarly journals Absorption, Distribution, Excretion, and Pharmacokinetics ofC-Pyronaridine Tetraphosphate in Male and Female Sprague-Dawley Rats

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Sang Hyun Park ◽  
Kannampalli Pradeep
Keyword(s):  
Clinical Trials ◽  
Small Intestine ◽  
Oral Administration ◽  
Female Rats ◽  
Sprague Dawley ◽  
Male And Female ◽  
Phase Ii Clinical Trials ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Peak Value

The main objective of this investigation was to determine the absorption, distribution, excretion, and pharmacokinetics of the antimalarial drug pyronaridine tetraphosphate (PNDP) in Sprague-Dawley rats. Following oral administration of a single dose (10 mg/Kg) ofC-PNDP, it was observed that the drug was readily absorbed from the small intestine within 1 hour following oral administration and was widely distributed in most of the tissues investigated as determined from the observed radioactivity in the tissues. The peak value of the drug in the blood was reached at around 8 hours postadministration, and radioactivity was detected in most of the tissues from 4 hours onwards.C-PNDP showed a poor permeability across the blood-brain barrier, and the absorption, distribution, and excretion ofC-PNDP were found to be gender-independent as both male and female rats showed a similar pattern of radioactivity. Excretion of the drug was predominantly through the urine with a peak excretion post 24 hours of administration. A small amount of the drug was also excreted in the feces and also in the breath. It was found that theCmax, AUC (0-inf), andTmaxvalues were similar to those observed in the Phase II clinical trials of pyronaridine/artesunate (Pyramax) conducted in Uganda.

scholarly journals Blockade of beta adrenergic receptors protects the blood brain barrier and reduces systemic pathology caused by HIV-1 Nef protein

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259446
Author(s):  
Jocelyn Rivera-Ortiz ◽  
Jessalyn Pla-Tenorio ◽  
Myrella L. Cruz ◽  
Krystal Colon ◽  
Jaileene Perez-Morales ◽  
...  
Keyword(s):  
Small Intestine ◽  
Female Rats ◽  
Sprague Dawley ◽  
Beta Adrenergic ◽  
Male And Female ◽  
Blood Brain ◽  
Male And Female Rats ◽  
Junction Protein ◽  
Systemic Pathology ◽  
Hiv 1

Combination antiretroviral therapy (cART) targets viral replication, but early viral protein production by astrocytes may still occur and contribute to the progression of HIV-1 associated neurocognitive disorders and secondary complications seen in patients receiving cART. In prior work with our model, astrocytic HIV-1 Nef expression exhibits neurotoxic effects leading to neurological damage, learning impairment, and immune upregulation that induces inflammation in the lungs and small intestine (SI). In this follow-up study, we focus on the sympathetic nervous system (SNS) as the important branch for peripheral inflammation resulting from astrocytic Nef expression. Male and female Sprague Dawley rats were infused with transfected astrocytes to produce Nef. The rats were divided in four groups: Nef, Nef + propranolol, propranolol and naïve. The beta-adrenergic blocker, propranolol, was administered for 3 consecutive days, starting one day prior to surgery. Two days after the surgery, the rats were sacrificed, and then blood, brain, small intestine (SI), and lung tissues were collected. Levels of IL-1β were higher in both male and female rats, and treatment with propranolol restored IL-1β to basal levels. We observed that Nef expression decreased staining of the tight junction protein claudin-5 in brain tissue while animals co-treated with propranolol restored claudin-5 expression. Lungs and SI of rats in the Nef group showed histological signs of damage including larger Peyer’s Patches, increased tissue thickness, and infiltration of immune cells; these findings were abrogated by propranolol co-treatment. Results suggest that interruption of the beta adrenergic signaling reduces the peripheral organ inflammation caused after Nef expression in astrocytes of the brain.

Influence of long-term ethanol treatment on in vitro biotransformation of benzo (a)pyrene in microsomes of the liver, lung and small intestine from male and female rats

1992 ◽  
Vol 44 (10) ◽  
pp. 1977-1984 ◽  
Author(s):  
Jeanine A.G. van de Wiel ◽  
Marly Meuwissen ◽  
Heimen Kooy ◽  
Peter H.S. Fijneman ◽  
Jan Noordhoek ◽  
...  
Keyword(s):  
Small Intestine ◽  
Female Rats ◽  
Ethanol Treatment ◽  
Male And Female ◽  
Male And Female Rats

scholarly journals Effects of Caecectomy on the Digestibility of Food and Rate of Passage of Digesta in the Rat

1982 ◽  
Vol 35 (4) ◽  
pp. 373 ◽  
Author(s):  
VJ Williams ◽  
W Senior
Keyword(s):  
Small Intestine ◽  
Young Adult ◽  
Transit Time ◽  
Crude Protein ◽  
Dry Matter ◽  
Alimentary Tract ◽  
Female Rats ◽  
Soluble Carbohydrate ◽  
Apparent Digestibility ◽  
Stock Diet

Minimum transit time through the alimentary tract of young adult female rats fed a stock diet adlibitum was reduced from 6� 6 � 0�4 h for sham-operated rats to 5�0 � 0�3 h for caecectomized rats, but there was no effect on transit time of digesta along the small intestine. Caecectomy decreased the apparent digestibility of crude protein, soluble carbohydrate, cellulose and hemicellulose. Digestibility of lipid was not affected. However, caecectomized rats did not increase their dry matter intakes to compensate for the reduced digestible energy intakes.

Pulmonary Effects due to Subchronic Exposure to Oil Fog

1990 ◽  
Vol 6 (1) ◽  
pp. 123-143 ◽  
Author(s):  
Maryjane K. Selgrade ◽  
Gary E. Hatch ◽  
Elaine C. Grose ◽  
Andrew G. Stead ◽  
Frederick J. Miller ◽  
...  
Keyword(s):  
Recovery Period ◽  
Dry Weight ◽  
Lavage Fluid ◽  
Female Rats ◽  
Lubricating Oil ◽  
Exposure Level ◽  
Concentration Effects ◽  
Post Exposure ◽  
Male And Female Rats ◽  
Histopathologic Changes

Male and in some cases female rats were exposed to an oil fog generated by flash vaporization and subsequent condensation of lightweight lubricating oil. Exposures were for 3.5 h/d, 4d/wk for 13 wk. Males were exposed at concentrations of 1.5, 0.5, 0.2 or 0.0 mg/l (1500, 500, 200, and 0 mg/m3) and a particle size of approximately 1 μm (mass median aerodynamic diameter). A number of biologic end-points were assessed the day after the last exposure and, in some cases, after a 4 wk recovery period. Effects of 1.5 mg/l on male and female rats were compared. Diffuse accumulation of macrophages in the alveoli was observed in all oil fog exposed groups. The degree of severity was concentration dependent. Histopathologic changes were more prominent in males than in females and represented the most notable gender-related differences. Histologic effects observed one day and 4 wk post exposure were similar. Minimal histopathologic changes and minimal increase in lavage fluid protein were the only effects observed at the 0.2 mg/l exposure level. There was a significant increase in lavage fluid protein, percent lavagable polymorphonuclear leukocytes and lung wet and dry weight following exposure to both 0.5 and 1.5 mg/l. At the highest exposure concentration effects on lung weights were still evident 4 wk post exposure. Pulmonary function endpoints including total lung capacity, vital capacity, residual volume, diffusing capacity to CO, compliance, and end expiratory volume (EEV) were unaffected by oil fog exposure with the exception of EEV in males exposed at the 1.5 mg/l level. All of the changes observed following oil fog exposure were consistent with a mild inflammatory edema.

Evaluation of thyroid function in neonatal and adult rats: The neglected endocrine mode of action

2003 ◽  
Vol 75 (11-12) ◽  
pp. 2055-2068 ◽  
Author(s):  
M. S. Christian ◽  
N. A. Trenton
Keyword(s):  
Metabolic Rate ◽  
Thyroid Function ◽  
Critical Period ◽  
Serum Levels ◽  
Thyroid Stimulating Hormone ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female Rats ◽  
Serum Tsh

Although known to regulate growth and development, cellular metabolism, the use of oxygen, and basal metabolic rate, thyroid hormones have been only minimally evaluated in neonatal rodents at critical times of development. Despite some modulation of metabolic rate by other hormones, such as testosterone, growth hormone, and norepinephrine, 3,5,3'-triiodothyronine (T3) and 3,5,3',5'-tetraiodothyronine (T4) are the most important metabolic rate modulators. Endpoints used for thyroid function assessment in neonatal and adult rats include thyroid-stimulating hormone (TSH), T3, and T4 levels and histopathology. In rodents, decreased serum levels of T3 and T4 and increased serum TSH levels, with sustained release of TSH and resultant follicular cell hypertrophy/hyperplasia, are typical hormonal and histopathological findings attributable to compounds altering thyroid function. Hypothyroidism early in the neonatal period can affect reproductive endpoints in both male and female rats, with the critical period of exposure being the first two weeks postnatal. Hypothyroidism has been shown to reduce gonadotrophin levels and delay pubertal spermatogenesis in male rats and to block gonadotropin-induced first ovulation in immature female rats by decreasing FSH and luteinizing hormone (LH) serum concentrations. Inclusion of evaluations of TSH, T3, and T4 assays in multigeneration and developmental neurotoxicity protocols may assist in risk assessments.

scholarly journals Production, absorption, distribution and excretion of vitamin B12 in sheep

1970 ◽  
Vol 24 (4) ◽  
pp. 857-877 ◽  
Author(s):  
R. M. Smith ◽  
Late H. R. Marston
Keyword(s):  
Small Intestine ◽  
Urinary Excretion ◽  
Alimentary Tract ◽  
Basal Diet ◽  
Dry Weight ◽  
Particulate Material ◽  
Vitamin B ◽  
Deficient Diet ◽  
Faecal Excretion ◽  
Micro Organisms

1. The efficiency of production and utilization of vitamin B12 was studied with sheep given a cobalt-deficient diet with and without supplementary Co (1 mg/d). Vitamin B12 to lignin ratios in rumen contents were used to estimate minimum rates of production and these were related to faecal and urinary excretion. Tissue distribution and excretion of vitamin B12 were studied with [58Co]cyanocobalamin and 5′-deoxyadenosyl[60Co]cobalamin.2. Labelled Co was rapidly sequestered by particulate material in the rumen and was largely excreted in the faeces. Most of the vitamin B12 in whole rumen contents was contained in micro-organisms, but was released on incubation at pH 2. Added cyanocobalamin was partly degraded in the rumen.3. The vitamin B12 to lignin ratio in rumen contents began to decline 1–3 d after cessation of a daily Co drench. Estimated ruminal production of vitamin B12 on full feed was not less than 400–700 μg/d with supplementary Co and 50–110 μg/d from the Co (0.01–0.05 μg/g dry weight) in the basal diet. Production of vitamin B12 appeared to be limited by food intake with or without additional Co.4. At full feed the efficiency of production of vitamin B12 from Co in the basal diet was about 13% while that from added Co was about 3%. Part of the vitamin B12 produced in the rumen was degraded before reaching the faeces and about 5% was absorbed. The minimum total requirements of sheep for vitamin B12 are assessed at about 11 μg/d.5. Injected 5′-deoxyadenosylcobalamin was better retained than injected cyanocobalamin, faecal excretion exceeded urinary excretion with both. Labelled cobalamin was selectively retained by liver (particularly by the mitochondria), kidneys and the walls of parts of the alimentary tract. Vitamin B12 was secreted into the duodenum and reabsorbed in the ileum, but little secretion occurred above the duodenum and little absorption below the small intestine.

The distribution of a primary infestation of Nippostrongylus brasiliensis in the small intestine of laboratory rats

Parasitology ◽  
1965 ◽  
Vol 55 (2) ◽  
pp. 313-324 ◽  
Author(s):  
M. R. Brambell
Keyword(s):  
Small Intestine ◽  
Adult Population ◽  
Relative Number ◽  
Egg Laying ◽  
Female Rats ◽  
Nippostrongylus Brasiliensis ◽  
Laboratory Rats ◽  
Male And Female Rats ◽  
Significant Difference ◽  
Reproducible Manner

The small intestine of rats was divided into twenty sections in a reproducible manner in order to study the distribution of Nippostrongylus brasiliensis by stretching it under a tension of 5g in adrenaline saline.A small but significant difference between the distribution of parasites in male and female rats was observed.As larvae had virtually ceased to reach the intestine by the fifth day all changes in distribution after that day were due to movements of the established adult population.Up to the twelfth day of a primary infestation the majority of the worms were found between the third and tenth sections, the population mode being in the fifth or sixth section. After the thirteenth day the number of worms in this region fell sharply.The female worms had not ceased from egg-laying by the time most of the worms were being rejected.The posterior half of the small intestine, i.e. the eleventh to twentieth sections, was not heavily parasitized, many of the worms seen being in passage to the anus.The first section was not parasitized until the seventh day, but thereafter remained parasitized until long after worms had disappeared from the more posterior sections.The relative number of male worms present increased as the infestation aged.Throughout the experiment the relative number of male worms present at the anterior end of the smaller intestine was higher than that at the posterior.Fourth-stage larvae were found chiefly in the sections that were later most heavily parasitized by adult worms.

Endogenous testosterone enhances growth hormone (GH)-releasing factor-induced GH secretion in vitro

1987 ◽  
Vol 113 (2) ◽  
pp. 249-253 ◽  
Author(s):  
L. Ohlsson ◽  
O. Isaksson ◽  
J.-O. Jansson
Keyword(s):  
Growth Hormone ◽  
Basal Medium ◽  
Dry Weight ◽  
Female Rats ◽  
Male Rats ◽  
Testosterone Replacement Therapy ◽  
Female Rat ◽  
Gh Secretion ◽  
Male And Female Rats

ABSTRACT The influence of endogenous gonadal steroids in male and female rats on basal and growth hormone-releasing factor (GRF)-stimulated GH secretion from perifused anterior pituitaries was studied. After 75 min of perifusion with basal medium, freshly dissected pituitaries were exposed to human GRF(1–44) (10 nmol/l) for 15 min. Neonatal (day 1–2) or prepubertal (day 25) gonadectomy of male rats suppressed baseline GH release (ng/min per mg dry weight) as well as GRF-stimulated GH release by 40–70%. This effect was slightly more pronounced in neonatally gonadectomized animals. In prepubertally gonadectomized male rats, the suppression of GH release was completely reversed by testosterone replacement therapy. In female rats, prepubertal gonadectomy did not affect GH secretion from perifused pituitaries. However, treatment of ovariectomized female rats with oestradiol reduced baseline and GRF-induced GH release to levels lower than those observed in sham-operated or vehicle-treated ovariectomized animals. The data suggest that testicular androgen secretion in adult male rats increases the pituitary GH release in response to GRF in vitro, whereas ovarian oestrogen secretion is of less importance for the GRF responsiveness of female rat pituitaries. J. Endocr. (1987) 113,249–253

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