Guinea Pig Feces Research Articles

Preliminary Study of Scent Rolling in Captive Wolves (Canis lupus L. 1758) in Response to Olfactory Enrichment.

Scent rolling, a behaviour observed in various large carnivores like wolves, entails the animal lowering its chin and neck towards a scent, followed by rubbing the head, neck, shoulders, and back into it. This behaviour is prevalent among wolves exposed to diverse scents, though its exact purpose remains uncertain. In this study, captive wolves at Osijek Zoo responded differently to odours during olfactory enrichment sessions. In the initial year of this study, the highest level of interest, evidenced by both the frequency of responses and scent-rolling behaviour, was noted when the wolves encountered odours such as curry and rosemary, along with deer/mouflon and rat faeces. While certain odours, such as llama faeces and deer/mouflon faeces, garnered longer durations of interest in the second year of study, others, like guinea pig faeces and oregano, elicited shorter responses. Female wolves demonstrated a higher level of engagement with scents compared with males, particularly through scent rolling behaviour, which was exclusively observed in females during the second year of this study. Interestingly, certain odours did not trigger scent rolling, suggesting selective preferences. On the other hand, sheep's wool induced the longest duration of scent rolling, and a lack of significant differences in behaviour was observed between morning and afternoon sessions. Despite the existence of multiple hypotheses put forward to explain the causation of scent rolling in wolves, it seems to be elicited by unfamiliar odours.

Increased abundance of bacteria of the family Muribaculaceae achieved by fecal microbiome transplantation correlates with the inhibition of kidney calcium oxalate stone deposition in experimental rats.

The incidence of nephrolithiasis is increasing rapidly worldwide. Calcium oxalate is the most common constituent, contributing to approximately 80% of all kidney stones. The gut microbiome, through its oxalate-degrading ability, may play a role in decreasing morbidity due to urinary calculus. Fecal microbiome transplantation (FMT) has been reported to be effective in restoring the gastrointestinal microbial community in different conditions. The transplantation of whole communities that have oxalate-degrading function may be a more effective strategy than the transplantation of isolated strains. FMT was carried out in male guinea pigs and male Sprague-Dawley laboratory rats (SDRs). Fresh feces were collected from guinea pigs housed in metabolic cages. SDRs were divided into four groups: two groups received standard rat chow (SC) (groups SC and SC + FMT), and two groups were fed a 5% potassium oxalate diet (OD) (groups OD + phosphate-buffered saline (PBS) and OD + FMT). On day 14, groups OD + PBS, OD + FMT, and SC + FMT received either PBS or guinea pig feces by esophageal gavage. The composition of the microbiota of guinea pigs and SDRs was analyzed using a 16S rRNA gene sequencing approach. Biochemical analysis of urine samples from SDRs revealed the presence of calcium oxalate (CaOx) crystals, which were presumed to originate from kidney stones. Renal function was examined using real-time PCR analysis and immunohistochemical staining for renin, angiotensin-converting enzyme, and osteopontin (OPN) expression. FMT resulted in a gut microbiota that was a mixture of guinea pig and SDR bacteria. A microbial network involving Muribaculaceae, Lactobacillus, and Bifidobacterium was activated by FMT in group OD + FMT. As a result, urinary oxalate, calcium, uric acid, creatinine and urea in urine samples were reduced significantly. Similarly, significant reduction of uric acid and blood urea nitrogen to creatinine ratio in serum samples was observed (p < 0.05). Microscopic observations revealed a high CaOx crystal score (4+) in the kidneys of rats in group OD + PBS, whereas a lower score (2+) was observed in the rats in group OD + FMT. Up-regulation of OPN and down-regulation of renin were also associated with FMT. A microbial network involving Muribaculaceae and other oxalate-degrading bacteria achieved by FMT was capable of reducing urinary oxalate excretion and CaOx crystal deposition in the kidney through increasing intestinal oxalate degradation. FMT may exert a renoprotective function in oxalate-related kidney stones.

Biotransformation of Morphinone and Its Glutathione Adduct Derived from Morphine by Anaerobic Gut Microbes in Guinea Pigs.

Morphinone (MO) and its glutathione adduct (MO-GSH) are excreted into bile of guinea pigs after subcutaneous administration of morphine (M). In the present study, we examined metabolites of M in guinea pig feces. Surprisingly, minimal amounts of MO and MO-GSH were excreted into the feces, whereas dihydromorphine (DHM) and dihydromorphinone (DHMO), which are not found in bile of guinea pigs administered M, were detected in the feces. Incubation of MO and MO-GSH with the contents of the large intestine under anaerobic conditions resulted in their conversion into DHMO. These results suggest that MO-GSH undergoes C-S cleavage by gut microbes to form MO, which is anaerobically reduced to DHMO excreted into feces.

약물 투여에 따른 기니피그 대장 운동 측정을 위한 압력센서 개발

Department of Electronics Engineering, Hanbat National University, Daejeon 34158, Korea(Received September 21, 2015; Revised December 2, 2015; Accepted December 7, 2015)Abstract: In this paper, in order to quantify the peristalsis occurrence in a guinea pig`s large intestine, a miniaturized air-gap capacitive pressure sensor was fabricated through micro-electro-mechanical system (MEMS). The proposed pressure sensor is a two-layered biocompatible polyimide substrate consisting of an air-gap capacitive plates between the substrates. The proposed pressure sensor was designed with a careful consideration of the structure and motility mechanism of the guinea pig`s large intestine. Artificial pellets were mounted on a prototype pressure sensor to provide some redundancies in the form of size and shape of the guinea pig feces. Capacitance of a prototype sensor was recorded to be 2.5 ~ 3 pF. This capacitance value was later converted to count value using a lab fabricated data conversion system. Sensitivity of the pressure sensor was recorded to be below 1 mmHg per atmospheric pressure. During in vivo testing, artificial peristalsis caused by drug injection was measured by inserting the prototype pressure sensor into the guinea pig’s large intestine and pressure data obtained due to artificial peristalsis was graphed using a labview program. The proposed pressure sensor could measure the pressure changes in the proximal, medial, and distal parts of the large intestine. The results of the experiment confirmed that pressure changes of guinea pig`s large intestine was proportional to the degree of drug injection.Keywords: Pressure sensor, MEMS, Polyimide, Artificial pellet, Intestinal motility ,-

Distribution and excretion of 2,2′,3,4′,5,5′,6-heptachlorobiphenyl (CB187) and its metabolites in rats and guinea pigs

4-Hydroxy (OH)-2,2′,3,4′,5,5′,6-heptachlorobiphenyl (CB187) is a polychlorinated biphenyl (PCB) metabolite present in human serum at the highest concentration of the PCB metabolites. Our previous study demonstrated that CB187 was metabolized by rat and guinea pig liver microsomes to the major metabolite 4′-OH-2,2′,3,3′,5,5′,6-heptachlorobiphenyl (CB178), and the two minor metabolites 4-OH-CB187 and 4′-OH-2,2′,3,5,5′,6-hexachlorobiphenyl (CB151). In this study, the distribution of these metabolites in serum, liver and kidney, and their fecal excretion, were examined in rats and guinea pigs intraperitoneally dosed with CB187. Similarly to the in vitro study, 4′-OH-CB178 was a major metabolite in the liver, serum and feces of both animal species on day 4 after CB187 injection, and the level in the liver was about 20 times higher in untreated guinea pigs than in untreated rats. In addition, 4-OH-CB187, a minor metabolite, was detected in the serum and kidneys, but not in the feces, of both guinea pigs and rats. Another minor metabolite, 4′-OH-CB151, was detected at a lower level only in guinea pig feces; little was found in the serum or liver of either animals. Over the 30d following CB187 injection into guinea pigs, 4′-OH-CB178 and 4-OH-CB187 in the serum was observed at higher level on day 4 and day 16 after injection, respectively. The majority of the 4′-OH-CB178 was rapidly excreted to the feces following unmetabolized CB187, whereas 4-OH-CB187 was not found in guinea pig feces and liver during 30d. These results support previous reports that 4-OH-CB187 is retained persistently in animal blood.

Olfactory memory in the mosquito Culex quinquefasciatus.

The cosmotropical urban mosquito Culex quinquefasciatus Say (Diptera: Culicidae) uses chemical cues to locate suitable water pools for oviposition. Although gravid females are innately attracted to or repelled by certain compounds, this study found that an individual mosquito's preferences for these odours could be altered greatly by prior experience. Mosquitoes reared in water containing skatole, at a level normally repellent to ovipositing females, preferred to oviposit in water containing that compound rather than in water with an otherwise attractive odour compound (P-cresol). This behaviour occurred regardless of whether mosquitoes were tested individually or in groups of up to 50 per cage. The F1 progeny of conditioned mosquitoes did not exhibit the parental preference, but were as susceptible to conditioning as their parents. Moreover, rearing mosquitoes in infusions of hay or animal (guinea-pig) faeces produced a similar although less dramatic change, such that the innate propensity for hay infusion could be cancelled by rearing in guinea-pig faeces infusion. The results demonstrated a change in odour preference by Cx. quinquefasciatus following exposure to the odour during development or pupal eclosion, suggesting that some form of larval conditioning or early adult imprinting occurred. Precisely when that conditioning occurred remains to be determined.

Rapid and specific determination of free cortisol in guinea pig urine and faeces by thin-layer chromatography-competitive protein-binding assay

The present work describes a specific, rapid and sensitive determination of free cortisol in the urine and faeces of guinea pigs. This method offers some advantages over previous methods including the use of dexamethasone as a marker for cortisol localization on TLC sheets, the use of buffer instead of organic solvents to recover cortisol from silica gel 60 and the rapidity of the competitive protein-binding assay (1–2 h).

Liquid Chromatographic Determination of Dipicolinic Acid from Bacterial Spores

Dipicolinic acid was determined by reverse-phase liquid chromatography. Elution was with 0.2 M potassium phosphate, pH 1.8, containing 1.5% tert-amyl alcohol or higher concentrations of lower alcohols or acetonitrile. The normal analytical range was 50 to 1,000 muM, which is equivalent to 0.1 to 1 mg of spores per ml with a relative standard error of 2 to 4% and a detection limit of <100 pmol. Dipicolinic acid was fully extracted from spores by heating at pH 1.8 for 10 min at 100 degrees C. Sporulating cultures may be analyzed in less than 20 min without separation of cells from media. Liquid chromatography was also used to detect dipicolinic acid in more complex substrates, e.g., guinea pig feces containing Metabacterium polyspora spores and canned food. Dipicolinic acid could be detected in unspoiled canned salmon containing <10 added Bacillus cereus spores per g.

Metabolism of phenformin in the rat and guinea-pig.

1. Following administration of [2'-14C]phenformin to rat and guinea pig, the guinea-pig showed a slower rate of excretion of radioactivity than the rat, together with a slower rate of metabolism, which may partly explain the increased pharmacological response of the guinea-pig to the drug. 2. The rat eliminated 26% of an intraduodenal dose of [2'-14C]phenformin (20 mg/kg) in the bile in 6 h compared to 6% in the guinea-pig. 3. The rat excreted large amounts of 4-hydroxyphenformin (free and conjugated with glucuronic acid) and also some unchanged phenformin, but the extent of metabolism varied with dose and route of administration. 4. The guinea-pig excreted no 4-hydroxyphenformin after an oral dose (25 mg/kg) and only a small amount after i.p. administration (12.5 mg/kg). After oral administration, guinea-pig urine contained an unidentified metabolite, and its glucuronide, which may be a product of aliphatic C- or N-hydroxylation and which accounted for 47% of the 24 h urinary radioactivity (17% of the dose). Guinea-pig faeces contained an unidentified metabolite which had similar chromatographic properties to the novel urinary metabolite.

Culturing Phlebotomus papatasii (Scopoli) in the laboratory

An original method of breeding Phlebotomus papatasii (Scop.) in the laboratory in the Egyptian climate was evolved, whereby the development of a fungal growth, a well-known obstacle, was prevented by incorporating, in the larval feeding medium, living material from cultures of a bacterium, Alcaligenes viscosus, which had been found to be the predominant micro-organism in samples of soil collected from breeding places of P. papatasii in the field. Later, eight other Schizomycetes were also found to keep in check the development of mould. Certain fungicides also gave satisfactory results. Breeding pots made of unglazed earthenware were used. A layer of finely sieved sand (18 meshes) about 5 cm. deep was placed at the bottom of the pot and moistened with sterile water. To a mixture of one part dried, ground, sieved guineapig faeces (60 meshes) and two parts sieved dry earth (60 meshes), sufficient of a water suspension of the bacterium was added to impart a damp but friable condition. Granules of this larval feeding medium were then scattered over the sand in a loose layer about 1 cm. thick. Each breeding pot was stood in a petri dish of water and was placed in a small muslin cage to which adult insects were introduced. The females, which obtained their blood-meals from three-day-old white mice, oviposited within the pots, and no eggs were laid elsewhere. Development from egg to adult was completed successfully in this medium, and a healthy culture of the insect was maintained in the laboratory for several years.

Some observations on the excretion of 17-ketosteroids and 17-ketogenic steroids by guinea-pigs.

SUMMARY 1. 17-Ketosteroids (KS) and 17-ketogenic steroids (KG) may be determined in guinea-pig urine by the method of Norymberski, Stubbs &amp; West [1953]. Studies on the fractionation of urinary steroids showed the method was applicable to the urine of pregnant guinea-pigs. 2. So little material in the faeces of guinea-pigs behaved as KS that excretion by this route may be ignored. 3. Daily vaginal lavages shortened the oestrous cycle in the guinea-pig and abolished the peak of KS excretion seen at oestrus in normal cycles. No consistent trend in the excretion of KG was seen during normal oestrous cycles. No cyclical change in KS excretion was seen after ovariectomy. 4. During pregnancy in the guinea-pig, there was a rise in the excretion of KG and KS. The increase was not abolished by ovariectomy. The rise did not occur in one adrenalectomized animal which went to term, though it continued to excrete significant amounts of KS. The contribution of the foetal adrenals to the excretion of steroids by the pregnant mother was probably small. 5. Non-specific adrenal stimulation caused a rise in the urinary excretion of KS and KG. 6. Fractionation of the KS released from the urine of an intact non-pregnant guinea-pig by a mild hydrolytic procedure gave five major compounds, one in the 11-deoxy and four in the 11-oxy fraction. All five compounds were excreted in increased amounts by a pregnant intact and by a pregnant adrenalectomized guinea-pig.

Intestinal sterols. I. Δ 7-cholestenol and 7-dehydrocholesterol in feces

1. 1. Fecal sterols from rats on a fat-free diet were found to contain substantial amounts of fast-acting sterols. Chromatography of the unsaponifiable matter resulted in the isolation of Δ 7-cholestenol, cholesterol, and coprosterol, and in the identification of 7-dehydrocholesterol. 2. 2. Feces from the guinea pig, dog, and man also contained substantial amounts of Δ 7-cholestenol. 7-Dehydrocholesterol was found in guinea pig feces, while only traces could be found in that of dog and man. 3. 3. The fast-acting sterol content of the feces was not altered by the ingestion of cholesterol, squalene, sulfasuxidine, fat, triolein, dextrin, or lactose. 4. 4. Much of the fecal Δ 7-cholestenol and 7-dehydrocholesterol apparently originated in the intestinal mucosa.

EXPERIMENTAL STUDIES ON STRONGYLOIDES AGOUTII IN THE GUINEA PIG

The suitability and tolerance of the guinea pig to infection with Strongyloides agoutii presented an opportunity for the study of the bionomics of this species in an experimental host.Serial transfer of this nematode through the guinea pig yielded a mixed type (free males and filariform larvae) of free-living development in faecal cultures which occasionally reverted to the indirect mode common to S. agoutii. A reversion to the indirect mode of development was produced when ova from faeces of guinea pigs infected with S. agoutii were cultured in sterile agouti faeces.The termination of the prepatent period of S. agoutii in the guinea pig was shown to range from 7 to 10 days, and 71% of 58 animals were positive by faecal test by the eighth day. The patent period ranged from three to eight weeks.The guinea pig was shown to develop an absolute acquired immunity to re-infection with S. agoutii. This resistance has been retained over a period of at least 6 to 13 months. An age resistance was not observed in animals one year old and over.