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

1997 ◽  
Vol 75 (3) ◽  
pp. 472-477 ◽  
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.

Effects of testosterone administration and gonadectomy on nuptial pad morphology in overwintering male leopard frogs, Rana pipiens

1995 ◽  
Vol 16 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Daniel G. Blackburn ◽  
Laura C. Lynch
Keyword(s):  
Rana Pipiens ◽  
Secretory Product ◽  
Physiological Control ◽  
Leopard Frogs ◽  
Testosterone Administration ◽  
Cytoplasmic Accumulation ◽  
Induced Changes

AbstractOverwintering Rana pipiens were studied to clarify physiological control of the nuptial pad, a digital specialization of male frogs that is used in mating. Testosterone cypionate implants stimulated nuptial pad growth in both castrated and sham-operated males relative to placebo-treated controls. Androgen-induced changes in the nuptial pad simulated seasonal recrudescence, and included significant increases in thickness of both the epidermis and dermis, formation of keratinized epidermal papillae, hypertrophy of the gland epithelium, enlargement of the gland lumina, and cytoplasmic accumulation of secretory product. Castration did not influence the response to testosterone, nor did it markedly affect nuptial pad morphology, probably because the pads were in maximal regression. These findings, in conjunction with previous work, implicate testicular androgens in seasonal cyclicity of the nuptial pad.

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

2004 ◽  
Vol 39 (3) ◽  
pp. 160-174 ◽  
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.

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

1992 ◽  
Vol 70 (4) ◽  
pp. 442-446 ◽  
Author(s):  
Bruce K. Rubin ◽  
Chris I. Cheeseman ◽  
Sita Gourishankar ◽  
Malcolm King
Keyword(s):  
Seasonal Variation ◽  
Seasonal Variability ◽  
Rana Pipiens ◽  
Mucociliary Clearance ◽  
Intestinal Transport ◽  
Leopard Frog ◽  
Intestinal Lumen ◽  
Leopard Frogs ◽  
Different Seasons ◽  
Frog Palate

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.

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

1997 ◽  
Vol 75 (11) ◽  
pp. 1883-1890 ◽  
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.

scholarly journals INDUCTION OF METASTASIS OF FROG CARCINOMA BY INCREASE OF ENVIRONMENTAL TEMPERATURE

1949 ◽  
Vol 89 (3) ◽  
pp. 269-278 ◽  
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.

Hopping and swimming in the leopard frog,Rana pipiens: I. Step cycles and kinematics

1996 ◽  
Vol 230 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Susan E. Peters ◽  
Lynn T. Kamel ◽  
David P. Bashor
Keyword(s):  
Rana Pipiens ◽  
Leopard Frog
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