[Glu34]-thymopoietin II fragment 32-45 and its three analogs were prepared by substitution of the amino acid residue at position 37. These peptides were synthesized by a conventional solution method, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole in trifluoroacetic acid in the presence of m-cresol. These peptides were tested for their effects on impaired T-cell transformation by phytohemagglutinin in the common variable immunodeficiency. The relative potency of the synthetic [Glu34]-thymopoietin II fragment 32-45 was one-half of that of synthetic thymopoietin II fragment 32-45. Among these tetradecapeptide analogs, one analog in which Val37 was replaced by Ile exhibited a potent activity which was more than that of the synthetic [Glu34]-thymopoietin II fragment 32-45. The relative potencies of Thr37 and Tyr37 analogs were one-third and one-half, respectively of that of the synthetic [Glu34]-thymopoietin II fragment 32-45.

Amino Acid Sequence↗

PubMedDate not supplied

Bopindolol and its metabolite 18-502 attenuate regional myocardial acidosis during partial occlusion of the coronary artery in dogs.

The effects of bopindolol (a new, nonselective beta-adrenoceptor antagonist) and its active metabolite, 18-502, on the regional myocardial pH during coronary occlusion were studied. Mongrel dogs were anesthetized with pentobarbital and the thorax was opened to expose the heart. The left anterior descending coronary artery (LAD) was incompletely (or partially) occluded so that the LAD flow could be reduced to about one third of the original flow. Regional myocardial pH of the LAD area was continuously measured by a tissue pH monitor. Drugs were injected intravenously 30 minutes after LAD partial occlusion. The myocardial pH in the LAD area decreased in response to LAD partial occlusion (from 7.3-7.4 to 6.72-6.92), and the low pH value was sustained for 60 minutes after LAD occlusion. Atenolol (1 mg/kg) decreased heart rate markedly and attenuated the regional myocardial acidosis induced by LAD partial occlusion. Bopindolol (1 mg/kg) decreased heart rate and 18-502 (0.5 mg/kg) decreased heart rate and blood pressure. Both drugs attenuated to a similar degree the decrease of regional myocardial pH induced by LAD occlusion. In the dog whose heart rate was maintained constant, however, bopindolol (1 mg/kg) did not attenuate the decrease of regional myocardial pH induced by LAD occlusion. These results suggest that both bopindolol and 18-502 attenuate the ischemia-induced regional acidosis of the myocardium as does atenolol, and, hence, have an anti-ischemic action. The beneficial action of bopindolol on ischemia-induced myocardial acidosis is possibly due to a decrease of heart rate, which corresponds to a saving of energy in the myocardial cells.

Acidosis↗

PubMedDate not supplied

Syntheses and effect of bursin and it analogs on the reduced B lymphocytes of uremic patients.

A selective B-lymphocyte-differentiating tripeptide, bursin, H-Lys-His-Gly-NH2, and its 10 analogs were synthesized by a solid-phase method and were tested for their effect on reduced B lymphocytes of uremic patients. Incubation of peripheral lymphocytes isolated from uremic patients with the synthetic bursin showed an enhancing effect on the reduced B lymphocytes. Of the s synthetic analogs, [Sar3]bursin exhibited the most potent effect.

Adjuvants, Immunologic↗