Form, weight, and indole content of pineal organs of red and grey kangaroos.

1965 ◽  
Vol 13 (5) ◽  
pp. 727 ◽  
Author(s):  
WB Quay ◽  
PC Baker

The pineal organ of the red kangaroo (Megaleia rufa) is shown to be distinguishable from that of the grey kangaroo (Macropus canguru) by being symmetrically bilobate instead of rounded distally. Pineal weights in the two species were similar. At least in M. rufa pineal size appeared to increase with age - from 6.4-15.6 mg in animals aged about 1 yr to 40.1 mg in a female 6+ years old. In comparison with the nocturnal indole contents of the pineal in rats, those of kangaroos have similar levels of 5- methoxy-N-acetyltryptamine (melatonin) and 5-hydroxyindole-3-acetic acid to the nocturnal values recorded in the literature for rats, but a lower level of 5-hydroxytryptamine (serotonin). Available information on vertebrate pineal weights and indoles does not provide evidence for any obviously distinctive evolutionary or functional status for the marsupial pineal organ as compared with that of some eutherian mammals or of some birds and reptiles.

2003 ◽  
Vol 22 (2_suppl) ◽  
pp. 1-10

Triacetin, also known as Glyceryl Triacetate, is reported to function as a cosmetic biocide, plasticizer, and solvent in cosmetic formulations, at concentrations ranging from 0.8% to 4.0%. It is a commonly used carrier for flavors and fragrances. Triacetin was affirmed as a generally recognized as safe (GRAS) human food ingredient by the Food and Drug Administration (FDA). Triacetin was not toxic to animals in acute oral or dermal exposures, nor was it toxic in short-term inhalation or parenteral studies, and subchronic feeding and inhalation studies. Triacetin was, at most, slightly irritating to guinea pig skin. However, in one study, it caused erythema, slight edema, alopecia, and desquamation, and did cause some irritation in rabbit eyes. Triacetin was not sensitizing in guinea pigs. Triacetin was not an irritant or a sensitizer in a clinical maximization study, and only very mild reactions were seen in a Duhring-chamber test using a 50% dilution. In humans, Triacetin reportedly has caused ocular irritation but no injury. Triacetin was not mutagenic. Although there were no available reproductive and developmental toxicity data, Triacetin was quickly metabolized to glycerol and acetic acid and these chemicals were not developmental toxins. Reports of 1,2-glyceryl diesters, which may be present in Triacetin, affecting cell growth and proliferation raised the possibility of hyperplasia and/or tumor promotion. The Cosmetic Ingredient Review (CIR) Expert Panel concluded, however, that the effects of 1,2-glyceryl diesters on cell growth and proliferation require longer ester chains on the glycerin backbone than are present when acetic acid is esterified with glycerin, as in Triacetin. On the basis of the available information, the CIR Expert Panel concluded that Triacetin is safe as used in cosmetic formulations.


1978 ◽  
Vol 26 (3) ◽  
pp. 487
Author(s):  
AW White ◽  
CJF Harrop

The development of the endocrine pancreas in kangaroos was examined histologically with tissue from three kangaroo species, the red kangaroo Megaleia rufa, the euro Macropus robustus erubescens, and the grey kangaroo Macropus giganteus. The relative size of the pancreas of the pouch young was found not to differ significantly from that of adults. Stages of pancreatic development were described from the frequency of the occurrence of the pancreatic epithelial ducts and the B or insulin-secreting cells, while the development and distribution of the A2 or glucagon-producing cells was also observed. In pouch young of less than 22 days of age the pancreas is dominated by ductular epithelial and undifferentiated pancreatic cells. From days 42 to 97 of pouch life B endocrine cells tend to be concentrated together and ductular tissue encroaches into areas previously dominated by connective tissue. After 120-135 days the first A2 cells are apparent and are usually located at the periphery of the islets, which now take on a distinctive appearance as the acinar tissue expands and separates them. After 135 days of pouch life A2 cells outnumber B cells; the endocrine tissue assumes an adult appearance after 150-160 days. The major difference between the development of pancreatic tissue in foetal sheep and pouch-young kangaroo is the prolonged dominance of connective tissue and the slow development of endocrine tissue in the former.


1997 ◽  
Vol 19 (2) ◽  
pp. 157 ◽  
Author(s):  
D Freudenberger ◽  
RB Hacker

In this study we examined the utility of manipulating artificial waters as a means of managing total grazing pressure in semi-arid rangelands of eastern Australia. We tested the efficacy of 'Finlayson trough' exclosure technology at three locations, over two summers, in paddocks with red kangaroos (Macropus rufirs) and two species of grey kangaroo (M. giganteus and M. fuliginosus). We also examined the effect of closing off five waters on the distribution of feral goat grazing intensity at one study site. Generally, there were no apparent reductions in kangaroo and goat grazing intensity following 6-10 weeks of water exclosure, the exception being a minor reduction in red kangaroo grazing intensity at one location. We concluded that kangaroo and goat grazing pressure cannot be substantially reduced by simply closing off waters in and near paddocks for several months. Key words: kangaroos, water exclosure. feral goats, grazing pressure, paddock spelling


1974 ◽  
Vol 1 (1) ◽  
pp. 27 ◽  
Author(s):  
M Griffiths ◽  
R Barker ◽  
L Maclean

In 8 periods between February 1967 and June 1968, covering a severe drought and subsequent rain, samples of 66 species of dicotyledons and 50 species of monocotyledons were collected from a large paddock in semiarid 'mulga-box' country in south-western Queensland. The mean N content of the dicotyledons ranged from 1.51 to 2.85 g/100 g DM, and that of the monocotyledons from 0.70 to 1.86 g/100 g DM.Stomach or faecal samples were analysed for plant parts. When known plant mixtures were given to 2 grey kangaroos (Macropus giganteus) and two sheep there was no species difference in the digestibility of the different plants or in the size distribution of faecal particles. Comparison of stomach and rectal samples from 5 shot kangaroos and 7 shot sheep showed quite good agreement. Samples of the faeces of sheep, grey kangaroo and a few red kangaroo (Megaleia rufa) were collected from the ground at the same intervals as the plant samples, dried and analysed for N and for plant parts. Detailed results are given. The grey kangaroos consistently ate more grasses than the sheep. The N content of sheep faeces was higher than that of kangaroo faeces, reflecting the higher protein intake of the sheep. The results confirm those of an earlier study (NAR 38, 1829) made in 1963–4 in a period of average rainfall. The authors conclude that competition between sheep and kangaroos is small.


1992 ◽  
Vol 40 (1) ◽  
pp. 91 ◽  
Author(s):  
R Osawa ◽  
PF Woodall

Macroscopic and microscopic dimensions of the intestines in five macropod species (the red kangaroo, Macropus rufus; the eastern grey kangaroo, M. giganteus; the agile wallaby, M. agilis; the swamp wallaby, Wallabia bicolor; and the red-necked pademelon, Thylogale thetis) were investigated allometrically in relation to body mass. In general, the length of the small intestine changed in an area : volume (A:V) compensating manner, but the circumference showed negative allometry such that the overall change in surface areas, both ground and mucosal (including the contribution of villi), were isometric but also included the coefficient derived from 'Kleiber's Law' (0.75) in their 95 and 99% confidence limits, respectively. Villous height and width generally showed no significant correlations with body size, but villous density was lower in large individuals. The allometry coefficient for the length of the large intestine was generally near the A:V compensating value (0.5) in most intraspecific analyses but much higher in the interspecific analysis, suggesting that some factor other than body size might be important (possibly dietary fibre). Caecal length was significantly correlated with body size only in two largest species (M. rufus and M. giganteus) and the interspecific analysis gave a value near A:V compensation).


1994 ◽  
Vol 17 (1) ◽  
pp. 73
Author(s):  
R.D. Barker ◽  
G. Caughley

Historical records, and the names of animals within Aboriginal languages, were analysed to compare the distribution and density of kangaroos at European contact with those of today. We gave up this attempt for the Eastern Grey Kangaroo, Macropus giganteus, presently restricted to the extreme south-east of the state, because it was never differentiated historically from the Southern Grey Kangaroo, M. fuliginosus, which occurs right across the southern portion of the state. The historical distribution of the latter species, and of the Red Kangaroo, M. rufus, seems to have been similar to their distribution today. Past densities are difficult to extract from historical records and are not sufficiently reliable to justify comparison with present densities. We note however an apparent increase in density of 'kangaroos' in the mid-1800s.


Parasitology ◽  
1964 ◽  
Vol 54 (1) ◽  
pp. 105-115 ◽  
Author(s):  
R. Mykytowycz

The incidence and prevalence of coccidia have been studied in populations of free-living red kangaroos, Megaleia rufa, and grey kangaroos, Macropus canguru, in four geographically distinct areas in Australia.Two new species of Eimeria—E. wilcanniensis and E. toganmainensis—are described from M. rufa, and five—E. cunnamullensis, E. gungahlinensis, E. purchasei, E. kogoni, and E. hestermani—from M. canguru.The incidence of coccidia ranged from 6 to 14% in populations of M. rufa and from 26 to 70% in M. canguru. The susceptibility of the animals to coccidia was analysed in relation to the tibia length. Red kangaroos with tibia approximately 360 mm. long and corresponding to an age of about 12 months were found to be most susceptible. No clinical cases of coccidiosis were seen in the field.Special thanks are due to the owners or managers of the properties on which the kangaroos were sampled; to members of the staff of the Regional Pastoral Laboratory ‘Gilruth Plains’ for their assistance in sampling, and to Messrs E. R. Hesterman, C. Kogon, and D. Purchase, who assisted in the field and the laboratory. Three species of Eimeria have been named after them in acknowledgement of their work. Messrs B. V. Fennessy and J. H. Calaby of this Division kindly read the manuscript.I wish to thank Dr G. B. Sharman for his permission to work with captive kangaroos in Canberra, and Mr E. Slater who took the photographs.


2005 ◽  
Vol 53 (4) ◽  
pp. 257 ◽  
Author(s):  
R. Zabaras ◽  
B. J. Richardson ◽  
S. G. Wyllie

The nature and distribution of the components, and evolution of the suite of compounds, secreted by the sternal gland of marsupials were studied. Individuals from nine families (18 species) of marsupials and from the echidna were sampled over an 18-month period. The assay system used gas chromatography/mass spectrometry and utilised thermal desorption with cryofocusing. Parsimony analysis, constrained by an assumed phylogeny, was used to examine the evolution of the suite of compounds detected. Large interspecies variation in secretion composition was observed with acetic acid, short-chain (C6–C10) aldehydes, long-chain (>C15) hydrocarbons and 1,1-bis-(p-tolyl)-ethane being constituents of the secretion of most species. The suite of compounds, however, varied from three compounds in the yellow-bellied and feathertail gliders to 41 in the koala. The most complex suites of compounds were found in the brown antechinus, red kangaroo, tammar wallaby and koala. Radical differences were observed between the secretions of related species (for example, brown antechinus and mulgara, tammar and parma wallabies, wombat and koala). Compounds appeared and disappeared repeatedly across the phylogeny. No compound constituted a synapomorphy for the Australian marsupials and only one compound was considered a synapomorphy for the Diprotodontia.


1971 ◽  
Vol 51 (1) ◽  
pp. 79-90 ◽  
Author(s):  
PAMELA A. SIMPSON ◽  
J. R. BLAIR-WEST

SUMMARY A renin—angiotensin system was shown to be present in several marsupial species in plasma and homogenates of the renal cortex. Species studied were: Eastern Grey kangaroo (Macropus giganteus), Red kangaroo (Megaleia rufa), common wombat (Vombatus hirsutus), pademelon (Thylogale billardierii), Bennett's wallaby (Wallabia rufogrisea frutica), a quokka (Setonix brachyurus) and a tiger cat (Dasyurus maculatus). Renin-substrate was found in the plasma of the Eastern Grey kangaroo, the Red kangaroo and the wombat. Renin was shown to be present in the plasma of all species by incubation alone or with heterologous marsupial renin-substrate. Plasma renin concentration and renal renin content were estimated by an established method using standard sheep renin-substrate. Plasma renin concentration was high, suggesting that marsupial renins have a high affinity for sheep substrate; renal renin estimates were low relative to eutherian species, suggesting that renal storage may be small. Plasma renin concentration and renal renin levels were proportionately related. Renin levels were consistently lowest in the wombat. Bilateral nephrectomy of an Eastern Grey kangaroo reduced plasma renin concentration to zero and increased renin-substrate concentration eightfold. The angiotensin-like incubation product from Eastern Grey kangaroo renin-substrate did not cross react with antibodies to [5-Ile]-angiotensin I, suggesting that the product has a different sequence of amino acids.


2000 ◽  
Vol 48 (4) ◽  
pp. 335 ◽  
Author(s):  
C. E. Blaney ◽  
T. J. Dawson ◽  
H. C. K. McCarron ◽  
R. Buffenstein ◽  
A. K. Krockenberger

The eastern grey kangaroo (M. giganteus) is usually found in mesic habitats but in the past 30–40 years it has expanded its range into arid rangelands. A suggested reason for this expansion has been the provision of additional water sites for domestic stock. In this study we examined aspects of kidney function and water metabolism of M. giganteus. This was done during normal hydration and water restriction so that the water-conserving abilities of M. giganteus could be compared with those of the red kangaroo (M. rufus), the habitat of which is arid rangelands and desert. The indices relative medullary thickness (RMT) and medullary to cortical ratio, derived from the morphology of the kidney, are indicators of renal concentrating ability. In M. giganteus both these indices were lower than in M. rufus: the RMT was 5.24 0.15 (mean s.e.) for M. giganteus and 6.00 0.10 for M. rufus. Measured maximal urine concentrations of these species were 2444 59 (M. giganteus) and 3135 165 mosmol kg–1 (M. rufus), with the respective maximum individual concentrations being 2752 and 4054 mosmol kg–1. Kidney function in hydrated and dehydrated M. giganteus was assessed via glomerular filtration rate, urine flow rate and concentration index. As measured by these parameters, M. giganteus had renal water-conserving capacities similar to, or superior to, those of many comparable-sized arid-zone-inhabiting placental mammals, but below those of M. rufus. Water metabolism, as measured by water turnover, showed a similar pattern.


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