Is there a seasonal variation in mucus transport and nutrient absorption in the leopard frog?

We postulated that as a hibernating species, frogs might have variable demands for nutrients at different seasons of the year and that this must be reflected in seasonal variations of physiologic processes related to nutrient transport and absorption. We examined the rate of mucus transport on the ciliated palate and the movement of nutrients across the intestinal lumen of leopard frogs, Rana pipiens. Mucus transport on the frog palate was strongly influenced by season, with maximal transport occurring in late June (Julian day 178, p = 0.0001; r = 0.58). This increased transport rate was associated with a summertime increase in mucus recoil (lower tangent δ) and a decrease in mucus hydration (increase in percent solids composition). Intestinal transport of leucine, lysine, and galactose did not appear to exhibit seasonal variability. These data suggest that different mechanisms may operate in determining seasonal variability in physiologic responses.Key words: mucociliary clearance, mucus viscoelasticity, intestinal absorption, Anura, seasonal variation.

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Mucus-depleted frog palate as a model for the study of mucociliary clearance

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.2.424 ◽

1990 ◽

Vol 69 (2) ◽

pp. 424-429 ◽

Cited By ~ 57

Author(s):

B. K. Rubin ◽

O. Ramirez ◽

M. King

Keyword(s):

Viscoelastic Properties ◽

Rana Pipiens ◽

Mucociliary Clearance ◽

Transport Rate ◽

Leopard Frog ◽

Mucociliary Transport ◽

Percent Solid ◽

Frog Palate ◽

The Stability ◽

Solids Content

To better understand the frog palate model of mucociliary transport, we measured the transport rate of mucus (MTR) from the leopard frog, Rana pipiens, and from the bullfrog, R. catesbeiana, recorded the stability of the MTR over a period of hours and days and over the course of 1 yr, and measured the viscoelasticity, percent solid composition, and spinnability (filance) of mucus from both species. Bullfrog mucus was less rigid than leopard frog mucus (log G* at 1 rad/s 2.09 vs. 2.61; P less than 0.01) and had a higher viscosity-to-elasticity ratio (tan delta at 1 rad/s 0.36 vs. 0.26; P less than 0.05). It also had a lower solids content (8.71 vs. 13.72%; P = 0.02), and there was a trend to lower spinnability for bullfrog mucus (filance 26.7 vs. 33.5 mm). These data suggest that bullfrog mucus has viscoelastic properties similar to normal mammalian respiratory mucus and leopard frog mucus has viscoelasticity similar to sputum samples. MTR was significantly slower in the winter than in the summer months (17 vs. 30 mm/min; P less than 0.0001). Although the leopard frog palate could be used for at least 7 consecutive days without exhaustion, bullfrog palates could be used for only 5 days. Palates of either species could generally be tested for 6 h/day without a significant decrease in MTR. These data clarify some of the sources of variability in the use of this system and suggest methods of standardization.

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Development and Survivorship of Northern Leopard Frogs (Rana pipiens) and Green Frogs (Rana clamitans) Exposed to Contaminants in the Water and Sediments of the St. Lawrence River near Cornwall, Ontario

Water Quality Research Journal ◽

10.2166/wqrj.2004.025 ◽

2004 ◽

Vol 39 (3) ◽

pp. 160-174 ◽

Cited By ~ 10

Author(s):

Tana V. McDaniel ◽

Megan L. Harris ◽

Christine A. Bishop ◽

John Struger

Keyword(s):

Rana Pipiens ◽

Early Stage ◽

Sediment Quality ◽

Leopard Frog ◽

Reference Sites ◽

Aquatic Life ◽

Leopard Frogs ◽

Water And Sediment ◽

Northern Leopard Frogs ◽

St Lawrence River

Abstract High levels of contamination in the aquatic environment and wildlife within the Ontario portion of the St. Lawrence River at the Cornwall Area of Concern (AOC) have raised questions about potential impacts on wildlife health. Northern leopard frog embryos were raised in two wetland sites within the AOC and at two reference sites to assess differences in water and sediment quality on survivorship and deformity rates. Chlorinated hydrocarbons (total polychlorinated biphenyls, organochlorine pesticides), polycyclic aromatic hydrocarbons, nutrients and heavy metals were measured in sediment and/or water from the study sites. Levels of some metals such as aluminium, cadmium, chromium and copper, exceeded federal and provincial guidelines for the protection of aquatic life, especially in the two AOC wetlands. Early stage tadpole survivorship was significantly lower and deformity frequency significantly higher at wetlands within the AOC; however, differences were likely not biologically significant. Survivorship and deformity rates of leopard frogs (Rana pipiens) at metamorphosis did not differ significantly among sites. Onset of metamorphosis was accelerated in tadpoles raised in wetlands within the AOC. Tadpoles raised in wetlands within the St. Lawrence River AOC took significantly less time to complete metamorphosis (53–55 days) than did tadpoles raised at reference sites (61–64 days). The phenology of metamorphosis was also more synchronous in tadpoles raised in the AOC, with all tadpoles reaching metamorphosis within a space of 3 to 7 days, as compared to 9 to 12 days at reference wetlands; these differences could not be accounted for by water temperature. Differences in development and survivorship rates between AOC and reference sites may be related to contaminant concentrations in water and sediment. However, no strong evidence for beneficial use impairment in terms of reproductive impairments or elevated deformity rates were seen from caged leopard frogs in the two AOC wetlands.

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Helminth communities in bullfrogs (Rana catesbeiana), green frogs (Rana clamitans), and leopard frogs (Rana pipiens) from New Brunswick, Canada

Canadian Journal of Zoology ◽

10.1139/z97-818 ◽

1997 ◽

Vol 75 (11) ◽

pp. 1883-1890 ◽

Cited By ~ 38

Author(s):

Donald F. McAlpine

Keyword(s):

New Brunswick ◽

Sexual Size Dimorphism ◽

Rana Pipiens ◽

Rana Catesbeiana ◽

Skin Penetration ◽

Life Cycles ◽

Leopard Frog ◽

Green Frog ◽

Leopard Frogs ◽

Helminth Communities

Twenty-three helminth species were identified from bullfrogs, Rana catesbeiana, green frogs, R. clamitans, and leopard frogs, R. pipiens, in New Brunswick. Digeneans dominated adult helminth communities in the aquatic bullfrog and semi-aquatic green frog; nematodes were dominant in the more terrestrial leopard frog. In green frogs and leopard frogs, richness and abundance were greatest in adults; in bullfrogs, juveniles showed the greatest richness and abundance. An increase in vertebrates in the diet of adult bullfrogs influences helminth communities in bullfrogs. Where Glypthelmins quieta and nematodes, which infect the host by skin penetration, predominate in green frogs and leopard frogs, respectively, the increase in epidermal area with age probably influences helminth abundance. Adult female leopard frogs are larger than males and harbour greater numbers of helminths. Within the most heavily sampled component communities only larval digeneans, and less frequently nematodes with direct life cycles, were common (i.e., in > 50% of hosts); other taxa were generally present at prevalences of < 20% and intensities of < 10 helminths per frog. Although wetland characteristics and helminth transmission dynamics play a role in producing variation in helminth communities among sites, ontogenetic shifts in diet and sexual size dimorphism within these anuran species are important in shaping helminth communities in individual frog hosts.

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Histology and histochemistry of androgen-stimulated nuptial pads in the leopard frog, Rana pipiens, with notes on nuptial gland evolution

Canadian Journal of Zoology ◽

10.1139/z97-057 ◽

1997 ◽

Vol 75 (3) ◽

pp. 472-477 ◽

Cited By ~ 13

Author(s):

M. S. Epstein ◽

D. G. Blackburn

Keyword(s):

Rana Pipiens ◽

Hormone Treatment ◽

Reproductive Season ◽

Leopard Frog ◽

Secretory Product ◽

Functional Characteristics ◽

Physiological Control ◽

Tyrosine Residues ◽

Leopard Frogs ◽

Gland Function

Nuptial pads are digital specializations of male frogs that cycle with the reproductive season and are considered to function in mating. Glandular secretions of the nuptial pads were analyzed histochemically in androgen-stimulated overwintering leopard frogs, Rana pipiens, to provide information on gland function and physiological control. In castrated and sham-operated male frogs treated with testosterone cypionate, the secretory product of the nuptial gland epithelium stained positive for carbohydrates and proteins, yet negative for lipids and glycogen. Secretions also stained positive for tyrosine residues and negative for acidic mucosubstances, sulphated mucosubstances, tryptophan, and cystine. Castration prior to hormone treatment had no effect on gland staining properties, and glands of cholesterol-treated castrates and intact controls appeared to be inactive cytochemically. Nuptial glands of frogs treated with 5-α-dihydrotestosterone were histologically similar to those of frogs treated with testosterone cypionate. Nuptial glands share structural and functional characteristics with integumentary mucous glands, and may have been modified evolutionary from that parent gland population.

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Seasonal Variation of Kaurenoic Acid, a Hypoglycemic Diterpene Present in Wedelia paludosa (Acmela brasiliensis) (Asteraceae)

Zeitschrift für Naturforschung C ◽

10.1515/znc-2004-3-419 ◽

2004 ◽

Vol 59 (3-4) ◽

pp. 229-232 ◽

Cited By ~ 16

Author(s):

Louisiane Faccio V. Bresciania ◽

Rosendo Augusto Yunes ◽

Cristiani Bürger ◽

Luis Eduardo De Oliveira ◽

Kauê Leal Bóf ◽

...

Keyword(s):

Seasonal Variation ◽

Kaurenoic Acid ◽

Different Seasons ◽

Hypoglycemic Diterpene

We evaluated the variation of the concentration of kaurenoic acid (1), which is a bioactive diterpene, in leaves, flowers, stems and roots from Wedelia paludosa (Acmela brasiliensis) for different seasons using the HRGC/FID method. The results indicated that the concentration of 1 is higher in the roots and stems during the autumn. The pharmacological results suggested that kaurenoic acid is responsible, at least in part, for the hypoglycemic potential detected in this plant.

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INDUCTION OF METASTASIS OF FROG CARCINOMA BY INCREASE OF ENVIRONMENTAL TEMPERATURE

Journal of Experimental Medicine ◽

10.1084/jem.89.3.269 ◽

1949 ◽

Vol 89 (3) ◽

pp. 269-278 ◽

Cited By ~ 31

Author(s):

Balduin Lucké ◽

Hans Schlumberger

Keyword(s):

Tissue Culture ◽

Elevated Temperature ◽

Constant Temperature ◽

Rana Pipiens ◽

Environmental Temperature ◽

Kidney Tumors ◽

Primary Tumors ◽

Metastatic Dissemination ◽

Leopard Frogs ◽

Tumor Bearing

Metastasis of the kidney carcinoma of leopard frogs (Rana pipiens) has been induced by exposing tumor-bearing animals for approximately 50 days to a constant temperature of 28°C. Under these conditions 54 per cent of the frogs developed secondary growths, whereas in groups kept at 18° or at 7° metastatic dissemination was found in only 6 per cent. Moreover, at the elevated temperature the metastases were usually more numerous and more widely disseminated; they were also fairly uniform in size, suggesting that they had developed at nearly the same time. Dissemination of the kidney tumors was influenced by the nutritional state of the frogs, occurring more readily in well nourished than in poorly nourished animals. Periodic Roentgen ray examinations showed that the size of the primary tumors was not significantly or uniformly affected during the course of the experiments. No correlation was found between change in size of the kidney tumors and the incidence of their metastasis. Although the mechanism by which temperature induces metastasis of frog carcinoma cannot as yet be elucidated, previous experiments with this tumor indicate that certain factors at least may be involved: Elevation of temperature has been found to cause more ready detachment of cells of frog carcinoma in tissue culture; to bring about increased velocity of locomotion of the detached cells; to lead more promptly and efficiently to vascularization of transplants; and to effect their greater invasiveness.

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Seasonal Variability in Middepth Gyral Circulation Patterns in the Central East/Japan Sea as Revealed by Long-Term Argo Data

Journal of Physical Oceanography ◽

10.1175/jpo-d-15-0157.1 ◽

2016 ◽

Vol 46 (3) ◽

pp. 937-946 ◽

Cited By ~ 1

Author(s):

Sok Kuh Kang ◽

Young Ho Seung ◽

Jong Jin Park ◽

Jae-Hun Park ◽

Jae Hak Lee ◽

...

Keyword(s):

Seasonal Variation ◽

Seasonal Variability ◽

Japan Sea ◽

Circulation Pattern ◽

Japan Basin ◽

Wind Stress Curl ◽

Argo Data ◽

Circulating Water ◽

Significant Seasonal Variation ◽

Water Columns

AbstractTrajectories of Argo floats deployed in the East/Japan Sea from 2001 to 2014 reveal that the middepth gyral circulation pattern of the Japan basin, the central part of the East/Japan Sea, undergoes a seasonal variation. The middepth circulation of the Japan basin is found to be characterized usually by the gyres trapped to the east of the Bogorov Rise (E-gyres) and those extending farther westward into the whole basin (BW-gyres). The E-gyre trajectories are generally associated with the turning of the floats toward deeper regions off the isobaths. This occurs in winter either on the northern or eastern side of the eastern Japan basin. It seems that the upstream part of the otherwise BW-gyre is subject to a strong negative wind stress curl in winter, and there the circulating water columns are driven toward the deeper region, thus triggering the formation of the E-gyre. The topographic effect associated with the Bogorov Rise seems to interfere thereafter in the process of determining the passage of the E-gyre. Otherwise, the water columns continue to flow along the isobaths, hence maintaining the BW-gyre. To the knowledge of the authors, this is the first observational evidence of seasonal variability in the middepth gyral circulation pattern in the East/Japan Sea. It suggests that oceanic middepth circulation, usually known to be quasi steady or slowly varying on climatological time scales, might also undergo a significant seasonal variation as it does in the East/Japan Sea.

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