Temperature-dependent elaboration of collagenase by the renal adenocarcinoma of the leopard frog, Rana pipiens.

Temperature-dependent Elaboration of Collagenase by the Renal Adenocarcinoma of the Leopard Frog, Rana p/p/ens1

Naturally occurring renal adenocarcinoma in North American leopard frogs, Rana pipiens, metastasize frequently (77%) when these ectothermic animals are kept in a warm environment but not when they are kept cold. We have found that expiants of these tumors secrete collagenase, an enzyme capable of dis solving connective tissue fibers and found previously to be closely correlated with metastatic ...

Continued Diminished Prevalence of the Lucke Renal Adenocarcinoma in Minnesota Leopard Frogs

No Luck? renal adenocarcinomas were detected at autopsy of 1216 northern leopard frogs (Rana pipiens) collected in Minnesota during the spring and autumn of 1978 and the spring of 1979, seasons in which the tumor was formerly obtained with a high frequency. The prevalence of renal tumors has been declining in Minnesota since at least 1966, and R. pipiens has become progressively scarce in Minne...

Frog lysozyme. I. Its identification, occurrence as isozymes, and quantitative distribution in tissues of the leopard frog, Rana pipiens.

In the course of examining the etiology of the Lucké renal adenocarcinoma of the frog, Rana pipiens, it was found that organs of the normal adult contain bacteriolytic enzymes. These enzymes all satisfied the six criteria for the identification of lysozymes and at least eight forms were separable by polyacrylamide gel electrophoresis. Their qualitative and quantitative distribution was organ-sp...

Renal adenocarcinomas promoted by crowded conditions in laboratory frogs.

reported by the Raffertys (10) in leopard frogs (Rana pipiens pipiens) that were maintained under crowded con ditions in the laboratory for periods ranging from 3 to 10 months. These incidences (20†" 50 %) are significantly higher than the incidence that Lucké(5) found in newly caught frogs (2.7 %) or in frogs that he maintained in the laboratory for a year or more (6.7 %). Subsequent studie...

Histology of the oviduct of the leopard frog, Rana pipiens.