TT_I_P: Theoretical and Translational Medicine I. Posters
Bányai Bálint1, Sipos Miklós2, Gerszi Dóra1,2, Dalloul Hicham2, Sziva Réka Eszter1,2, Kollarics Réka1,2, Haoran Ke1, Török Marianna1, Szekeres Mária1, Nádasy György László1, *Hadjadj Leila2, *Horváth Eszter Mária1, *Várbíró Szabolcs2
1 - Department of Physiology Semmelweis University, Budapest
2 - Department of Obstetrics and Gynecology Semmewleis University, Budapest
The higher cardiovascular risk associated with vitamin D hypovitaminosis is well known, however the effects of vitamin D on the cardiovascular system are less understood.
Our aim was to investigate the early effects of insufficient vitamin D levels on vascular reactivity and assess the sex-related differences in rat carotid arteries.
3-4 weeks old male and female Wistar rats, were divided into four groups according to vitamin D intake. For 8 weeks, half of the male (M) and female (F) animals were provided with optimal vitamin D levels (MD+ N=13; FD+ N=13), while their counterparts were fed with vitamin D deficient chow (MD- N=11; FD- N=11). Phenylephrine (Phe)-induced contraction and acetylcholine-dependent relaxation of carotid rings were studied under normal conditions and under nitric oxide synthase (NOS) and cyclooxygenase (COX) inhibition (L-NAME, INDO) using wire myography. Density of elastic and smooth muscle elements in the vascular walls was assessed resorcin-fuchsin (RF) staining, and immunohistochemical staining for the smooth muscle α-actin (SMA) and endothelial nitrogen-oxide synthase (eNOS).
Gender specific difference in Phe-dependent contraction was observed at 10-6 M Phe concentration, male animals showed significantly stronger contraction. Vitamin D deficiency significantly increased contraction independently from gender. (FD+:113±3,4, FD-:124±3,6, MD+:129±8,3, MD-:154±6)
Inhibition of NOS significantly increased contraction in all groups, INDO pretreatment caused no further change. INDO alone reduced contraction only in the FD+ group.
Ach-dependent relaxation showed a vitamin D independent sex difference: relaxation was significantly lower in male groups compared to females. Vitamin D deficiency failed to induce significant change in this function in both genders. (FD+:74±4,2, FD-:73±5,6, MD+:59±5,7, MD-:51±5)
Based on SMA and RF staining, vitamin D deficiency reduced the density of elastic elements in females and smooth muscle elements in males. Vitamin D deficient male rates showed reduced eNOS immunoreactivity of the carotid artery.
Vitamin D deficiency leads to increased contractile reactivity of the carotid artery in both sexes. Our results suggest that vitamin D deficiency leads to gender specific changes in eNOS expression and elastic and smooth muscle elements density of these vessels.
Semmelweis University, Doctoral School of Theoretical and Translational Medicine