Erythrocyte lysate increases intracellular Ca2+ ([Ca2+]i) and contracts cerebral arteries in vitro and has been suggested to be the cause for cerebral vasospasm. We investigated the effect of hemolysate on L-type Ca2+ channels directly by using patch clamp techniques in freshly isolated single smooth muscle cells from rat basilar artery. Patch clamp studies revealed a whole-cell current which resembles the L-type Ca2+ current reported by others. Hemolysate reduced the amplitude of the L-type Ca2+ channel current. The effect of hemolysate was reversible by washout and repeatable. Hemolysate was separated into two fractions by using filter membranes. The fraction > 1 kDa which contains oxyhemoglobin and other proteins mimicked the effect of hemolysate, while the fraction < 1 kDa and ATP were without effect. We conclude that hemolysate does not increase [Ca2+]i by activation of L-type Ca2+ channel.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMedDate not supplied

Changes in vasoactive properties of blood products with time and attempted identification of the spasmogens.

The contractile activity of various fresh, or incubated blood fractions was studied in vitro using the isolated canine basilar artery. Significantly greater contraction was induced by fresh platelet rich plasma (PRP) and serum compared to red blood cells (RBC). Following incubation, the contractile activity of RBC increased, reaching a plateau at day-3 and it was maintained for at least 14 days, while both PRP and serum lost most of their activity after 24 h of incubation. The contractions induced by fresh blood fractions were only partially blocked by desensitization of 5-hydroxytryptamine (5-HT) receptors or by the 5-HT antagonist methysergide. D-600 effectively antagonized the response to all blood fractions. Biochemical analysis of the incubated RBC by means of Sephacryl S-200 column chromatography and SDS-urea polyacrylamide gel electrophoresis revealed that the contractile substance possessed a molecular weight of about 60,000 daltons. Vasoactivity was only present in one peak of the chromatographically eluted fractions which was shown to possess a similar absorption spectrum to that of hemoglobin. Hemoglobin concentration was highest in day 3, 7, and 14 fractions and may be correlated with the contractile activity of incubated samples.

Animals↗

PubMedDate not supplied

Intracranial vascular complications of choriocarcinoma.

Choriocarcinoma is the most malignant of the tumors of chorionic tissue that (most commonly) arise from fetal tissues and invade the maternal vasculature. Two cases of choriocarcinoma are presented. One patient had a suprasellar mass in conjunction with a neoplastic carotid-cavernous fistula. The mass and the fistula disappeared after apparently successful radiation therapy and chemotherapy. The second patient had a ruptured arterial aneurysm associated with an intracerebral hematoma treated by evacuation of the hematoma and resection of the aneurysm. The vascular complications of this tumor are reviewed, and a management plan is suggested.

Adolescent↗