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Chromatographic procedures have been developed for resolving all of the known enkephalins and endorphins on a single column. The effect of eluant pH on the retention times and separation of the enkephalins and beta-endorphin was determined. By combining these separations with a sensitive radioreceptor assay it is possible to assay all of the opioid peptides in the pituitary gland or in various regions of the brain from individual small laboratory animals.

Two novel heterobifunctional cross-linking reagents, which can be used to attach photoactivatable nitroaryl azides to primary amino groups of proteins, have been synthesized. The two compounds, N-5-azido-2-nitrobenzoyloxy-succinimide and ethyl N-5-azido-2-nitrobenzoylaminoacet-imidate-HCl, as well as ethyl 4-azidobenzimidate-HCl have been attached to lysine residues of cobra venom phospholipase A2 without a loss in enzymatic activity. Subsequent illumination of the modified forms of the enzyme at appropriate wavelengths under conditions in which the native enzyme exists in an aggregated state led to the formation of covalently linked dimers and large aggregates which could be separated by electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate.

An enkephalin-containing peptide originating from ovine adrenal proenkephalin has been purified and sequenced. The sequence of the peptide is: GLY-GLY-GLU-VAL-LEU-GLY-LYS-ARG-TYR-GLY-GLY-PHE-MET (preproenkephalin 128-140) which represents a portion of peptide F (preproenkephalin 107-140). This peptide has a sequence identical to that of bovine preproenkephalin 128-140 while it differs from the corresponding human sequence in positions 129, 131 and 133.

Twelve patients (mean age 48.8 years, 5 females) with untreated labile or mild essential hypertension completed a randomised, double-blind crossover study comparing the effects of two-week courses of indomethacin, sulindac and matching placebo upon sitting and standing blood pressure. Both indomethacin and sulindac significantly increased systolic BP when compared with placebo; indomethacin tended to have a greater pressor effect than sulindac. During treatment with indomethacin, the mean BP rose from 136/86 to 149/92 (sitting), and from 136/93 to 150/99 standing. The extent of the pressor response was unrelated to baseline BP. The results indicate that both non-steroidal anti-inflammatory drugs (NSAIDs) have a significant pressor effect in individuals with untreated labile or mild hypertension. The fact that sulindac had a pressor effect implies that this response may be unrelated to inhibition of renal prostaglandins, or that the renal-sparing effect of sulindac is only relative. Extra-renal prostaglandins may play a role in the control of BP in this population. Individuals with labile or mild hypertension do not appear to exhibit exaggerated pressor responses during treatment with these NSAIDs, as similar increases in BP have been reported in normal subjects.

Proenkephalin peptide F immunoreactivity, epinephrine, and norepinephrine were measured in the plasma of endurance-trained and untrained male subjects riding on a bicycle ergometer at 28%, 54%, 83%, and 100% of maximum oxygen consumption (VO2). At rest the trained group had peptide F levels almost twice the level of the untrained group, whereas all other variables measured were the same. The maximum epinephrine and norepinephrine levels were found at 100% exercise intensity, with a precipitous drop in the levels at 5 min of recovery. In contrast, the peptide F immunoreactivity reached a maximum at 5 min of recovery and was still substantially above the initial level after 15 min of rest. In addition, the trained subjects showed another peak of peptide F immunoreactivity at 54% VO2max. Possible explanations for the different patterns of catecholamine and peptide F levels are presented.

A 24 amino acid polypeptide that does not originate from (pre)proenkephalin has been isolated from ovine adrenal chromaffin granules. Its sequence is: Arg-Leu-Pro-Gly-Glu-Leu-Arg-Asn-Tyr-Leu-Asp-Tyr-Gly-Glu-Glu-Val-Gly-Glu- Glu-Ala -Ala-Arg-Gly-Val. This peptide is generated from a precursor molecule that has also been purified and partially sequenced. The proteolytic cleavage occurs at a triple Arg site. A search of the available protein sequence data banks shows very little homology to any known protein.

A variety of Gram-negative and Gram-positive bacteria possess crystalline surface layers, although little is known of their function. We previously have shown that the high molecular weight surface-array proteins of Campylobacter fetus are important in both the pathogenicity and antigenicity of this organism. For biochemical and immunological characterization, we purified high molecular weight (100,000, 127,000, 149,000) surface-array proteins from three C. fetus strains using sequential gel filtration and ion exchange high performance liquid chromatography. These proteins are acidic with pI values between 4.12 and 4.25 and contain large proportions of acidic amino acids (19.7%-22.0%) in addition to hydrophobic amino acids (37.3%-38.5%). They share a novel amino-terminal sequence through at least 19 residues. Carbohydrate analysis using periodic acid-Schiff staining and treatment with trifluoromethanesulfonic acid shows no evidence of glycosylation. Antiserum to a purified Mr = 100,000 protein from C. fetus 82-40 LP cross-reacts with three other purified C. fetus surface-array proteins by enzyme-linked immunosorbent assay with titers greater than 12,800. We conclude that: 1) there is a family of surface-array proteins of C. fetus with common structural and antigenic characteristics; 2) that these molecules have similar biochemical characteristics to surface-array proteins described for other bacteria; but however, 3) by amino-terminal sequence analysis these are unique.

We have isolated a previously unknown peptide and its precursor from bovine adrenal medullary chromaffin granules. The peptide sequence is Leu-Pro-Val-Asn-Ser-Pro-Met-Asn-Lys-Gly-Asn-Glu-Val-Met-Lys. The peptide is cleaved from the precursor at a Lys site. The sequence shows no homology to any known protein in the largest sequence data bank available.

Beta-blockers are often prescribed for patients who are asymptomatic and for whom the benefits of therapy are likely to be small. Side-effects are therefore of great importance. Symptoms such as muscle fatigue and peripheral coldness are commonly associated with treatment with beta-blockers but these subjective phenomena are difficult to detect and quantify so that their prevalence and severity are uncertain. Conventional symptom questionnaires may be relatively insensitive and visual analogue scales (VAS), which permit interval quantification of subjective phenomena, may have some advantages. They appear to be able to detect the presence of tiredness of the legs and peripheral coldness among hypertensive patients taking beta-blockers and are more sensitive than descriptive or 'category' questionnaires. However, some patients find VAS hard to understand and a minority of patients score erratically for all symptoms. A most detailed explanation is of paramount importance. Scores derived from VAS surveys are not normally distributed and should be examined using non-parametric statistical methods; normalising transformations do not improve the sensitivity of the method.

The amino terminal sequences of bovine and human adrenal medullary chromogranin A have been determined. Their sequences are identical and also identical to the published sequence of secretory protein I from the parathyroid gland. This data indicates that the previously published sequence of chromogranin A is incorrect at residues 2 and 19. These data confirm earlier observations of a substantial similarity between secretory protein I and chromogranin A and, in fact, strongly suggest that they are identical.

Fourteen patients (four females) with chronic atrial fibrillation were entered into a randomized, double-blind crossover study to compare the effects of treatment with diltiazem alone, digoxin alone, and a combination of diltiazem plus digoxin. The dose of digoxin was adjusted so as to achieve serum concentrations within the range 1.3-2.6 nmol l-1 between six and eight hours after dosing. Four patients were withdrawn from the study; three patients experienced side effects while taking diltiazem and one reverted to sinus rhythm while taking digoxin. Among the remaining 10 patients, mean heart rates were significantly lower during treatment with the combination of digoxin and diltiazem than with digoxin alone both at rest, after exercise and during ambulatory ECG monitoring. Post-exercise heart rates were reduced by 15% with combination therapy when compared with digoxin alone (151.9 vs. 128.1 bpm), but there was no evidence that this reduction in ventricular rate was associated with improved exercise tolerance. The results suggest that further reduction of the rapid ventricular rates seen in digitalized patients with AF by the use of diltiazem does not appear to be of benefit in the majority of patients.