Beneficial effect of a multistrain synbiotic prodefen® plus on the systemic and vascular alterations associated with metabolic syndrome in rats: The role of the neuronal nitric oxide synthase and protein kinase A

A high fat diet (HFD) intake is crucial for the development and progression of metabolic syndrome (MtS). Increasing evidence links gut dysbiosis with the metabolic and vascular alterations associated with MtS. Here we studied the use of a combination of various probiotic strains together with a prebiotic (synbiotic) in a commercially available Prodefen® Plus. MtS was induced by HFD (45%) in maleWistar rats. Half of the MtS animals received Prodefen® Plus for 4 weeks. At 12 weeks, we observed an increase in body weight, together with the presence of insulin resistance, liver steatosis, hypertriglyceridemia and hypertension in MtS rats. Prodefen® Plus supplementation did not a ect the body weight gain but ameliorated all the MtS-related symptoms. Moreover, the hypertension induced by HFD is caused by a diminished both nitric oxide (NO) functional role and release probably due to a diminished neuronal nitric oxide synthase (nNOS) activation by protein kinase A (PKA) pathway. Prodefen® Plus supplementation for 4 weeks recovered the NO function and release and the systolic blood pressure was returned to normotensive values as a result. Overall, supplementation with Prodefen® Plus could be considered an interesting non-pharmacological approach in MtS.This research was funded by Italfarmaco, S.A (L.O.U. 83; 0138/2018), CiberCV (Grant number: CB16/11/00286), the European Regional Development Grant (FEDER) (Comunidad de Madrid, Grant number B2017/BMD-3676), and R + D projects for young researchers, Universidad Autónoma de Madrid (Comunidad de Madrid (SI1-PJI-2019-00321). R.R.-D. received a fellowship from Juan de la Cierva Program (IJCI-2017-31399)

A blunted sympathetic function and an enhanced nitrergic activity contribute to reduce mesenteric resistance in hyperthyroidism

We aimed to determine whether an experimental model of hyperthyroidism could alter the function of sympathetic and nitrergic components of mesenteric innervation. For this purpose, male Wistar rats were divided into (1) control rats (CT) and (2) rats infused with L-Thyroxine (HT). Body weight gain and adipose tissue accumulation were lower in HT rats, while systolic blood pressure and citrate synthase activity in the soleus muscle were increased by HT. In segments from the superior mesenteric artery, the application of an electrical field stimulation (EFS) induced a vasoconstrictor response, which was lower in arteries from HT animals. The alpha-adrenoceptor antagonist phentolamine diminished EFS-induced vasoconstriction to a lower extent in HT arter-ies, while the purinergic receptor antagonist suramin reduced contractile response to EFS only in segments from CT. In line with this, noradrenaline release, tyrosine hydroxylase expression and activation and dopamine β hydroxylase expression were diminished in HT. The unspecific nitric oxide synthase (NOS) inhibitor L-NAME increased EFS-induced vasoconstriction more markedly in segments from HT rats. NO release was enhanced in HT, probably due to an enhancement in neuronal NOS activity, in which a hyperactivation of both PKC and PI3K-AKT signaling pathways might play a relevant role. In conclusion, perivascular mesenteric innervation might contribute to reduce the vascular resistance observed in hyperthyroidism.This research was funded by CiberCV (Grant number: CB16/11/00286), the European Regional Development Grant (FEDER) (Comunidad de Madrid, Grant number B2017/BMD-3676), Ministerio de Economía, Industria y Competitividad (SAF 2016-80905-P) and R + D projects for young researchers, Universidad Autónoma de Madrid (Comunidad de Madrid (SI1-PJI-2019-00321)