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A monoclonal antibody has been produced that recognizes the cytochrome P450 form, cytochrome P450IA1, but not cytochrome P450IA2 in rats and recognizes a single protein band of similar mol. wt on immunoblots of human liver microsomes. Immunohistochemical studies have been carried out with this antibody to investigate the localization and distribution of cytochrome(s) P450 of the P450IA family in human liver. Cytochrome P450IA was identified in both adult and fetal liver and in each case it was localized predominantly to hepatocytes. In adult liver there was a heterogeneous distribution of cytochrome P450IA immunoreactivity with cytochrome P450IA mainly present in zone 3 hepatocytes of the liver acinus. Within fetal liver there was a uniform distribution of cytochrome P450IA immunoreactivity with no apparent zonal distribution. Bile duct epithelium did not show definite immunostaining for cytochrome P450IA in either adult or fetal liver.

The purpose of this study was to validate an experimental method for quantifying the pain producing potential of intravenously administered solutions. Response was measured in a Broome restraint tube modified by the addition of strain gauges. Struggling caused flexion of the tube, changing strain gauge output and increasing output variance. In experiment 1, five groups of 10 male Sprague Dawley rats were given intravenous injections of 1 ml of saline, acetate, HCl, citric acid vehicles, or KCl over a 1-min period. Results showed significant increases in output variance between saline and treated groups during the infusion period. In experiment 2, five groups of five rats were given intravenous injections of saline or 0.1, 0.05, 0.025, or 0.0125 M KCl. Rats responded in a dose-dependent manner, demonstrating the sensitivity of this technique. In experiment 3, two groups of four rats were given injections of morphine sulfate (2 or 4 mg/kg, ip) prior to administration of 0.05 M KCl. Two additional groups received no pretreatment prior to administration of saline or 0.05 M KCl. Results demonstrate that morphine ablates the response to intravenous administration of KCl. This model provides information concerning the pain producing potential of intravenously delivered compounds or formulations.

Concurrent use of more than one antibiotic in clinical treatment of serious infections is common. Trospectomycin sulphate, a semi-synthetic aminocyclitol, may be used in combination with the aminoglycoside gentamicin sulphate. To investigate any potential interaction, trospectomycin and gentamicin toxicity were assessed in vitro using a two-factor response surface design study with each factor at four levels. Cultures of the LLC-PK(1) cell line (proximal renal epithelium) were treated with 0, 125, 250 or 500 mug/ml of the drugs, alone or in combination, and cytotoxicity was evaluated at 3, 7, 10 and 14 days of continuous exposure. Cytotoxicity was assessed by morphological and biochemical criteria (lactate dehydrogenase, LDH; alkaline phosphatase, ALP; gamma-glutamyl transpeptidase, GGT; aspartate transaminase, AST; alanine transaminase, ALT; acid phosphatase, ACP). ALP, GGT, LDH and AST activity increased in the control cultures over the experimental period. Cytoplasmic vacuolation, increased number of detached cells and reduced dome formation occurred at 250 and 500 mug gentamicin/ml and in combination with these levels of trospectomycin at study days 10 and 14. There was a statistically significant (P < 0.05) interaction (decrease) for ALP and GGT at study day 14. In summary, the LLC-PK(1) culture system provides a useful in vitro screen to evaluate potential xenobiotic interactions to assess nephrotoxicity.

Bovine somatotropin (bSt) was given either orally or subcutaneously to groups of female hypophysectomized rats daily for 9 days. Ten rats per dose group were given oral dosages of 0 (buffered-water vehicle control), 40, 400, 2000, and 4000 micrograms of bSt per day. Similar groups of ten rats each received subcutaneous doses of 0 (buffered-water vehicle control), 15, 30, and 60 micrograms of bSt per day. Rats were weighed daily to observe their body-weight gain, which is a measure of the biological activity of bSt in the hypophysectomized rat. At study termination, serum of treated rats was monitored for the presence of bSt and antibody to bSt. Bovine somatotropin was detected in the serum of the subcutaneously treated rats, but not in those rats treated orally. Of 18 rats treated subcutaneously with bSt, 14 developed antibodies to bSt, whereas of 38 rats treated orally with bSt, 11 developed antibodies. Subcutaneously treated rats grew in a dose-related manner as expected in this assay. Orally administered bSt failed to elicit a growth response at any dose in this sensitive bioassay system. The data suggest that neither bSt nor growth-promoting fragments of bSt are absorbed after oral administration of doses up to 40,000 micrograms/kg/day in the hypophysectomized rat.

Gibberellin-like activity in berries of both ;Tokay' (seeded) and ;Seedless Tokay' grapes (Vitis vinifera L.) at different stages of development was determined. Activity in both seeded and seedless berries was mainly in the acidic ethyl acetate fraction. In seeded berries there was very high activity beginning at the early fruit-set stage and persisting for about 3 weeks after which the activity fell to low level and vanished by the middle of July. On August 1 there was another activity peak. The activity in ;Seedless Tokay' was similar except the decline was considerably more rapid and a secondary peak was reached in mid-June instead of August. The gibberellin-like substances in the acidic ethyl acetate fraction occurred mainly between R(F) 0.3 and 0.6 when the chromatogram was developed with ammoniacal isopropanol.The gibberellin-like substances from both types of berries were active in dwarf pea, dwarf corn, and lettuce hypocotyl bioassays, but not in the cucumber hypocotyl test. The role of gibberellin-like substances in berry development is discussed.

Roots of Vitis vinifera L., were treated with benzyladenine when the plant shoots were 38 cm long. Seventy-two hours after benzyladenine treatment, apical or basal leaves on separate shoots were exposed to (14)CO(2). Control shoots received (14)CO(2) but no benzyladenine. Application of benzyladenine directed (14)C-photosynthate to roots, but a small amount of radioactivity was detected in the shoot tip when (14)CO(2) was administered to an apical leaf. Distribution of radioactivity among the sugar, organic acid, and amino acid fractions was altered by benzyladenine treatment. In all parts of plants with roots treated with benzyladenine and apical leaf fed (14)CO(2), the percentage of the total label in the sugar fraction comprised of fructose was generally more than twice that in control plants.

Leaves of Vitis vinifera L., nearly fully expanded, imported only trace amounts of (14)C following assimilation of (14)CO(2) by a lower leaf on the same shoot, but benzyladenine (BA) application at 4.4 x 10(-3)m caused a marked increase in the movement of (14)C into these leaves. Older leaves near the shoot base were less responsive; BA treatment alone had little effect on import of labeled assimilates from adjacent leaves but when the BA-treated leaves were darkened there was an increased import of labeled materials. When these 2 treatments were combined and applied to leaves on shoots with ringed bases, relatively high levels of radioactivity were detected in the BA-treated leaves but under these conditions darkening, without the application of BA, also resulted in an increased import of (14)C. Accumulation of imported (14)C was found to be restricted to the area of the leaf blade treated with BA. Separation of labeled compounds in ethanol extracts of treated leaves showed a lower percentage of radioactivity present in the sugar fraction from BA-treated leaves and an increased percentage present in the amino acid fraction.

The effect of exogenous growth regulators on movement of assimilates into flowers and young fruits of ;Black Corinth' grapes was studied. Clusters were treated with growth regulator and after 0.5 hr to 5 days the leaves above the clusters were exposed to (14)CO(2). Control shoots received (14)CO(2) but no growth regulator. At harvest, counting and radioautographic techniques were used to ascertain amount and distribution of activity in clusters. Clusters were dipped in 4-CPA (4-chlorophenoxyacetic acid), GA(3) (gibberellic acid), or BA (benzyladenine). All berries were heavier than controls within 3 days. Total counts in the fruits were increased by 4-CPA, and the distribution of radioactivity among the sugar, organic acid, and amino acid fractions was usually altered by all treatments. In a time series experiment, within 6 hr after treatment of fruits with GA(3) there was almost an 8-fold increase in total counts relative to the control. After 12 hr there was about a 9-fold and 6-fold increase in counts in tartaric and malic acids, respectively, and in gamma-aminobutyric acid, pipecolic acid, and valine increases of 56, 150, and 330%. Radioactivity in fructose was increased 70% in gibberellin-treated clusters over the controls. After 96 hr there were only about 1000 cmp per g fr wt in controls, but there were about 31,000 cpm counts in treated clusters. Treatment of clusters with gibberellin attracted less assimilates into the fruits when shoots had also been sprayed with gibberellin. Dipping portions of clusters in gibberellin increased the movement of (14)C assimilates into the treated portions. Hormonal control of mobilization is discussed.

During the prebloom and bloom stages, no movement of labeled photosynthates occurred from a shoot of Vitis vinifera L. fed with (14)CO(2), to an adjacent shoot on the same spur. Movement of labeled assimilates into the unfed shoot was induced when this shoot was sprayed with 2.89 x 10(-3)m gibberellic acid during the prebloom stage. During the bloom stage darkening or defoliation of the unfed shoot resulted in the import of labeled photosynthates from the adjacent fed shoot. Similarly, movement of (14)C into an untreated shoot was induced by removing the terminal 7.5 centimeters and deblossoming the fed shoot. During the berry set stage, translocation of labeled photosynthates from a newly exporting leaf was upwards to the shoot tip, but the direction of movement was reversed by removal of the shoot tip or by darkening or removal of the leaves below the fed leaf. Translocation of photosynthates was predominantly basipetal from a fed leaf near the base of the shoot during the berry set stage, but upward movement was induced by darkening or defoliation of the upper part of the shoot.