Participation of COX-1 and COX-2 in the contractile effect of phenylephrine in prepubescent and old rats

Abstract

Vascular reactivity can be influenced by the vascular region, animal age, and pathologies present. Prostaglandins (produced by COX-1 and COX-2) play an important role in the contractile response to phenylephrine in the abdominal aorta of young rats. Although these COXs are found in many tissues, their distribution and role in vascular reactivity are not clear. At a vascular level, they take part in the homeostasis functions involved in many physiological and pathologic processes (e.g., arterial pressure and inflammatory processes). The aim of this study was to analyze changes in the contractile response to phenylephrine of thoracic/abdominal aorta and the coronary artery during aging in rats. Three groups of rats were formed and sacrificed at three distinct ages: prepubescent, young and old adult. The results suggest that there is a higher participation of prostanoids in the contractile effect of phenylephrine in pre-pubescent rats, and a lower participation of the same in old rats. Contrarily, there seems to be a higher participation of prostanoids in the contractile response of the coronary artery of older than pre-pubescent rats. Considering that the changes in the expression of COX-2 were similar for the three age groups and the two tissues tested, and that expression of COX-1 is apparently greater in older rats, COX-1 and COX-2 may lose functionality in relation to their corresponding receptors during aging in rats.

Evaluation of Cardiovascular Effects of Carvacrol in a D-(+)-Galactose-Induced aging Model

“…Increasing and cumulative addition of Phe promoted concentration-dependent contraction in arteries of all four experimental groups. The Dgal group (91.2 ± 9.03%, n=9) showed no significant increase in contractile response by Phe when compared to the CTL group (100.5 ± 12.2%, n=11), suggesting that the D-(+)-galactoseinduced accelerated aging model does not develop hypercontractility of the rat mesenteric artery, corroborating with Guevara-Balcazar et al (2017) [23], who identified similar results. On the other hand, in animals treated with carvacrol at a dose of 50 mg/kg, a significant increase in the contractile response to Phe was observed (Dgal+C50, 120.4 ± 10.4 %, n=9).…”

The physiological and pharmacological roles of prostaglandins in hair growth

“…They are signaling molecules observed in most tissues, and have various functions including the activation of the inflammatory response, pain production, and fever [ 12 ]. The cyclooxygenase (COX) enzyme metabolizes the arachidonic acid into prostaglandin H2 (PGH 2 ), which is a kind of origin prostaglandin [ 13 , 14 ]. The molecular structure of PGH 2 can be modified by specific synthase to produce several isoforms of prostaglandin such as prostaglandin D2 (PGD 2 ), prostaglandin E2 (PGE 2 ), and prostaglandin F2 alpha (PGF 2α ).…”