SUMMARYThe simultaneous deleclion of anti-La. anti-60-kD Ro and anli-52-k[5 Ro anlibodies by immunobloUing is greatly improved by changing the crosslinking level in the gel lo an aerylamide/ bisacrylamide ratio of 19:1. Using this method Tor the analysis of a number of systemie lupus erythemalosus (SLE) and Sjogren's syndrome patienl sera il was observed thai antibody to the 52-kD Ro protein without anii-60-kD Ro antibody was restrieted to Sjogren's syndrome patients (9/26). whereas antibody to tlie 60-kD Ro protein without contaminating anti-52-kD Ro antibody was only found in SLE patients (8/38). Moreover, in Sjogren's sydrome patient sera anti-Ro antibody was found only in eombination with anti-La antibody (20/26), whereas in SLE patienl sera anti-Ro antibody eould be found without detectable anti-La speeifieity (4/38). Double immunofluoreseenee mieroseopy revealed that the 52-kD Ro and lhe 60-kD Ro proteins eo-locali/e in the cytoplasm as well as in the nucleus, whereas immunoprecipitalion of f'-P]-labelled HeLa cell extract wiih monospecific anti-52-kD Ro and anli-60-kD Ro sera showed that bdlh proteins are assoeiated wilh lhe Ro RNAs, These dala suggest the presenee of boUi lhe 52-kD and lhe 60-kD Ro proteins in the same ribonueleoproiein eomplexes. To study the evolutionary conservation ofthe 52-kD Ro. the 60-kD Ro and the La proteins, e.xiracts of eell lines derived from various mammalian speeies were analysed on Western blots using monospecitic human antibodies. In eontrast lo lhe(il)-kD Roand the La aniigens whieh are well conserved in evolution, the 52-kD Ro antigen could be detected in primate eells only by this immunologieal approach.

The clinical utility of the carbonic anhydrase (CA) inhibitor acetazolamide (ACTZ) is limited because of rapid development of tolerance to its effects. Tolerance is thought to develop as a result of glial cell proliferation and/or increased CA synthesis. DBA mice, susceptible to audiogenic seizures (AGSs) in an age-dependent manner, have increased CA activity as compared with C57 (non-audiogenic seizure susceptible) mice at 21 and 110 days of age. The present work utilized ACTZ to help determine the relationship between increased CA activity in brain and AGSs in DBA mice. Also, minimal electroshock seizure threshold (EST) was measured at various ages in DBA and C57 mice to determine age-related changes in CNS excitability. EST was significantly lower in DBA as compared with C57 mice at 18 days and between 40 and 115 days of age, suggesting that DBA mice remain hyperexcitable to electrical stimulation after they develop resistance to AGSs. ACTZ ED50s against maximal electroshock seizures (MES) were significantly higher in DBA as compared with C57 mice at 26,36, and 115 days of age. This finding correlates with higher CA activity in this strain at 110 days of age, noted previously. However, at 21 days of age, when CA activity is also higher in DBA versus C57 mice, there were no significant differences in ACTZ ED50s against MES between the strains. ACTZ ED50s against AGSs in DBA mice were considerably lower than ACTZ ED50s against MES in either strain, suggesting that a particular fraction of CA is intimately involved in the production of AGSs.(ABSTRACT TRUNCATED AT 250 WORDS)

DBA/2J (DBA) mice are susceptible to audiogenic seizures (ASs) in an age-dependent manner. Anion transport as measured by radioiodide uptake was determined in thyroid gland, salivary gland, skeletal muscle, cerebral cortex, cerebellum, brainstem, and CSF from these mice at various ages. Anion transport was also determined in C57BL/6J(C57) mice, an AS-resistant strain. In thyroid, DBA mice had an enhanced ability to concentrate iodide at 21 days of age when they have maximal AS susceptibility, as compared with the same-aged C57 mice. This difference in thyroid function was less marked at 40 days of age, when DBA mice are less AS susceptible, and was absent at 110 days of age, when DBA mice are AS resistant. In brain, differences in iodide uptake were also noted between these two strains of mice at 21 days of age. DBA mice had an increased concentration of iodide in CSF, an indication that they have a defect in the transport of iodide out of the CSF across the choroid plexus. In addition, DBA mice had a lower ratio of cerebral cortex to CSF iodide, which suggests that DBA mice have a defect in the transport of this anion into cerebral cortical cells from brain interstitial fluid. These differences in iodide transport in brain decreased with age as the AS susceptibility of DBA mice decreased. These results suggest a relation between anion transport in thyroid gland, cerebral cortex, and choroid plexus and AS susceptibility in DBA mice at 21 days of age.

The effects of thyrotrophin, hypophysectomy, and chronic treatment with thyroxine and methimazole on radioiodide uptake (thyroid/plasma (T/P) 125I-ratio), protein and DNA contents and activities of Na+, K+-ATPase, HCO-3 ATPase, and carbonic anhydrase (CA) of rat thyroid gland were evaluated. Thyrotrophin given to intact rats slightly increased thyroid iodide uptake, did not affect protein or DNA content, and slightly inhibited CA activity (units/g cell water). Hypophysectomy markedly decreased T/P 125I-ratio, increased protein content, decreased activity of Na+, K+ -ATPase, and slightly increased HCO-3 -ATPase(nmol/mg DNA per min) and CA (units/g cell water) activities. Thyrotrophin given to hypophysectomized rats (as compared with untreated hypophysectomized control animals) markedly increased T/P 125I-ratio, slightly decreased protein content and decreased Na+, K+-ATPase and CA activities. Chronic treatment with methimazole increased T/P 125I-ratio, decreased protein content, markedly increased NA+, K+-ATPase and HCO-3-ATPase activities, and decreased CA activity. Chronic treatment with thyroxine, in contrast, decreased T/P 125I-ratio, decreased Na+, K+-ATPase activity, and increased CA activity. There was a significant inverse correlation between T/P 125I-ratio and CA activity in follicular cells for the various induced functional states of the thyroid.

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