Biomedical subjects

M A Quintana

Publications and source records attributed to M A Quintana.

3 recordsLinked to original sources

PubMed1995

Dental mineralization.

Extracellular matrix components and cell-derived microstructures are implicated in mineralization processes which occur in dental tissues. The respective role(s) of collagenic and non-collagenic matrix components are reviewed: phosphorylated and non-phosphorylated proteins, proteoglycans and phosphpholipids. Space-filling amphiphilic molecules seem to play an important role in the preorganization and oriented deposition of calcium phosphate on structures serving more or less as passive support in dentine as well as in enamel.

Amelogenesis↗

PubMed1988

Effects of indomethacin and diclofenac on cerebral blood flow in hypercapnic conscious rats.

Cerebral blood flow (CBF) was measured in conscious rats treated with indomethacin, diclofenac or the vehicle for indomethacin during hypercapnia of three different degrees. Similar values were found for CBF in rats treated with diclofenac or vehicle and there was a direct correlation between CBF and the arterial blood carbon dioxide values. In contrast, indomethacin completely blocked the increase of CBF during hypercapnia. These results suggest strongly that prostaglandins are not involved in the hypercapnia-induced cerebral vasodilatation.

Animals↗

PubMed1983

Effects of aspirin and indomethacin on cerebral circulation in the conscious rat: evidence for a physiological role of endogenous prostaglandins.

The purpose of this work was to evaluate the effects of equipotent doses of two different inhibitors of cyclo-oxygenase, indomethacin and aspirin, on cerebral blood flow and cerebral vascular resistances in the conscious undisturbed rat, using the reference sample radioactive microsphere method. We found that both, aspirin (50 mg/kg) and indomethacin (5 mg/kg) at 3, 15 and 60 min after their intravenous administration, increased cerebral vascular resistances and decreased cerebral blood flow to a similar extent. Both drugs completely abolished the hypotensive effect of 5 mg/kg i.v. arachidonic acid and they did not change arterial PO2, PCO2 or pH values. We conclude that the pharmacological inhibition of cyclooxygenase in the conscious undisturbed rat leads to a cerebral vasoconstriction and consequently to a decrease in cerebral blood flow. Our results evidence that prostaglandins are a physiological factor that actively contributes to the maintenance of cerebral circulation.

Animals↗