Stable hybrid zones in which ecologically divergent taxa give rise to a range of recombinants are natural laboratories in which the genetic basis of adaptation and reproductive isolation can be unraveled. One such hybrid zone is formed by the fire-bellied toads Bombina bombina and B. variegata (Anura: Discoglossidae). Adaptations to permanent and ephemeral breeding habitats, respectively, have shaped numerous phenotypic differences between the taxa. All of these are, in principle, candidates for a genetic dissection via QTL mapping. We present here a linkage map of 28 codominant and 10 dominant markers in the Bombina genome. In an F2 cross, markers that were mainly microsatellites, SSCPs or allozymes were mapped to 20 linkage groups. Among the 40 isolated CA microsatellites, we noted a preponderance of compound and frequently interleaved CA-TA repeats as well as a striking polarity at the 5 0 end of the repeats.

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Human urinary kallikrein was purified by gel filtration on Sephacryl S-200 and affinity chromatography on aprotlnin-Sepharose, followed by ion exchange chromatography on DEAE-Sepharose. In dodeeylsulfate gel electrophoresis two protein bands with molecular weights of 41,000 and 34,000 were separated. The amino acid composition and the carbohydrate content of the kalllkrein preparation were determined; isoleuelne was identified as the only aminoterminal amino acid. The bimolecular veloeity constant for the inhibition by dilsopropyl fluorophosphate was determined as 9 +2 I tool -1 min -1. The hydrolysis of a number of substrates was investigated and AePheArgOEt was found to be the most sensitive substrate for human urinary kallikrein. Using this substrate an assay method for kallikrein in human urine was developed.It was shown by radiolmmunoassay that pig pancreatic kallikrein can be absorbed in the rat intestinal tract. Furthermore, in dogs the renal excretion of glandular kallikrein from blood was demonstrated by radioimmunological methods.

Abstracts 431 isotopic method of Schayer, and expressed as dpm per gram. Varying concentrations of bradykinin were used. One group received 50 micrograms per injection, another 250 jug. By day 14 tumors on animals from the 250 /~g bradykinin dose group were retarded in growth (6. 2-+ 0.7 S.E.M mm diameter increase) as compared with the saline-injected controls (16 + 2.5 S.E.M. mm diameter increase). The 50 #g dose group was intermediate in growth rate between the control and the 250 #g group. Results are significant by value of less than ap.005 T-test. Splenic HDC the 250/~g bradykinin dose group was significantly elevated (p = .05) over the saline control group, (111,905 + 23,000 dpm vs 49,597 -+ 18.077 dpm), 8 hamsters per group. Normal hamster histidine decarboxylase levels were measured at 300,000 -+ 95,000 dpm. Histological study demonstrated no lymphocytic infiltration in non-injected tumor controls; saline-injected controls contained scattered lymphocytes, and bradykinin-injected tumors were massively infiltrated by mononuclear cells (with evidence of increased tumor cell destruction in these areas), as well as mononuclear cells in non-injected tumors on two-tumor bearing bradykinin injected animals. Second tumors on controls contained no lymphocytic infiltration. Non-injected tumors on two-tumor animals were not retarded in growth significantly despite accumulation of mononuclear cells. These findings suggest a potential role for inter-related vasoactive substances (which act as mediators of inflammation) in the growth and development of neoplasms and possibly in the therapy of neoplasia. ISOLATION OF PORCINE SUBMANDIBULAR KALLIKREIN M. LEMON, B. FOR G-BREY and H. FRITZ Institut fiir Klinische Chemie und Klinisce Biochemie der Universitiit Miinchen, Miinchen, W. GermanyKallikrein from porcine submandibular glands was isolated by acetone precipitation, batchwise DEAE-sephadex adsorption, and affinity chromatography on trasylol-linked sepharose resin. Benzamidine was used to elute bound kallikrein from the resin. The specific activity of the purified kallikrein, assayed by the combined ADH/BAEE method, was 107.4 U/E280. When this kallikrein was subjected to disc gel electrophoresis at pH 8.9, only one band was observed. However, after treatment with SDS, disc gel electrophoresis gave one major band with 3 faster-running, less intense bands. Isoelectric focusing of the kallikrein on polyacrylamide gel discs gave an isoelectric point of 3.8 -+ 0.2. This is similar to the isoelectric point 4.05/g pancreatic kallikrein B, measured on a sucrose-density gradient (Fiedler, Hirschauer and Werle, 1970).